Uh oh. A/C not blowing cold.

[Morpheus]

Gents,

For the last couple of months, my car has been down for a cooling system overhaul (Rad, hoses, water pump)/tune-up/VOD job. During the course of this work, I had the condenser hanging down, resting on one end. I didn't notice any strain on the hose connections, and make sure that nothing was forced any way it didn't want to be, and all seemed fine. My AC was blowing ice cold before the project.

39755

So, fast forward to this past weekend, and I get the car running again. Tuned the CO, set the idle, all is good. Except, the air isn't blowing cold. The compressor isn't even cycling. Dammit. So, I go to AutoZone and get one of these:
http://www.autozone.com/a-c-charging-and-refrigerant-freon/r134a-refrigerant/a-c-pro-r-134a-a-c-pro-premium-not-for-hybrid-vehicles-with-electrical-driven-compressors/974769_0_0/?checkfit=true
(my car was previously converted to R134 by the PO).

I hook up the hose, the gauge reads 0. I put in about 1/2 the can, and the compressor starts cycling. Yay!

All in all, I put in most of the can. I was paranoid about over charging it. The gauge was reading in the "green zone" and the air was blowing cold, so I left it.

Next day, I take the car out. Air is not quite as cold as it was, but I figure that I can just put in the rest of the can when I get home, no big deal. Then I notice that the compressor isn't cycling. Huh. Head scratcher.

I get home, hook up the can again and notice that the pressure is right in the middle of the "green zone". I suppose this to mean that the pressure is still being held, but all I know is the system isn't blowing cold or even cool at this point. I am beginning to wonder what could be wrong. I have narrowed it down to a few possibilities:

1. The "leak sealing" additives in the can I put in the system clogged the orifice tube.
2. I have a fat leak somewhere, possibly at the condenser.
3. My compressor seals are toast. (This one might be the most probable, as I have spatter marks on the underside of my engine cover just above the AC compressor pulley)
4. All of the above.

I will admit that I am a complete dunce when it comes to AC systems. What limited knowledge I do have led me to the conclusions above. Now, this is where the collective DMCTalk expertise will come in handy:

I have an early car, with the early A/C accumulator setup as seen on this pic from Hervey's site:
39756

Let's hypothetically say that I have to open up the system to replace one or more components. It is my understanding that when you do so, you should replace a few things automatically, such as the accumulator, orifice tube, and o-rings. That said, must I stay with the "early style" accumulator? I'm not sure if they are even available anymore. Furthermore, if I have to change that, I'm probably going to need new hoses and compressor as well. If i'm leaking at the condenser, then I'm looking at a new one of those now too.

I need guidance.

[Morpheus]

Update:

I read the reviews on that can of refrigerant I bought, and almost all of them say that the gauge is horrendously wrong. So, it's possible that I over charged it. Would overcharging prevent the compressor from cycling and make the air blow lukewarm?

[Bitsyncmaster]

I would suggest you inject a UV dye and then look for leaks with the UV light. When I changed my hoses on the condenser, they were pretty loose OEM hoses. Maybe hanging on the hoses moved them and make them leak.

[David T]

At this point, if you aren't sure what you are doing and don't have the equipment, it is time to go to an A/C shop. There should be plenty of them in FL. The system in the Delorean is not so unusual so any good shop should be able to fix it. Make sure you tell them it was converted.

[opethmike]

Dear Guru,

Considering your responses in the door strut thread, I am highly disappointed that you made no remarks about 'blowing' in this thread. Please do better next time.

-Not Guru

[DMCVegas]

At this point, if you aren't sure what you are doing and don't have the equipment, it is time to go to an A/C shop. There should be plenty of them in FL. The system in the Delorean is not so unusual so any good shop should be able to fix it. Make sure you tell them it was converted.

I would second that. If you're going to be messing around with hoses, you at least need to wear some thick leather gloves and a face mask to prevent frostbite if you're not sure of the condition of things.

If however you want, you CAN "rent" things like an A/C pump and other tools from AutoZone to do the work yourself. But you really need to read up on that first.

If it were me, I would first pull a vacuum on the system, let it sit, and see if you have any leaks. If so, check your lines and hoses for tightness, maybe even check/replace seals, and start again. But that is only if you feel confident.

If you are not sure about this, go with Dave's advice and take it to a professional shop.

[DeLorean937]

Are you getting power at the compressor? I had the curled red wire break inside the connection to the cars connection and it looked like it was connected when it was not. I metered it and was getting power I just had to fix the lead. We can checked on my gauges when you make it down if you want. Also, I think I have an extra new accumulator laying around in the box if it comes to that.

[dn010]

Are you testing the pressure at rest or with the compressor jumped or cycling? Are your hoses original? If you end up replacing the condenser, most of them will come as a kit with the accumulator and orifice tube. If you change out hoses and accumulator be extra careful on the connections especially the ones connecting to the evaporator - you don't want to complicate things even more by adding dash removal to replace an evaporator with a broken connection.

[kings1527]

The best place to start with where you're at would be to evacuate the system and start from there. Pull your orifice tube, examine it, and replace it anyways since it's a cheap part. You can definitely convert your setup to a later-style accumulator which crosses over to a 1984 Corvette, I believe. The AC system was designed by Harrison Radiator which is now owned by GM but it's basically a GM-based system. Not very tricky.

With AC systems, I've found it to be much easier to start at level one with an empty system and go from there. Once you get all the new parts and your accumulator conversion purchased and installed, replace all the seals (Pep Boys has those, too), pull a vacuum on the system and make sure it holds. True, a vacuum would be second best to charging the system with dry nitrogen when it comes to finding leaks but I've found vacuum to be highly effective and much more practical when it comes to having the right equipment. An AC vacuum that's pretty darn good can be purchased at Harbor Freight for about $90. Which brings me to my next point.

AC work is all about having the right equipment. You'll need a vacuum, GOOD gauges (yellowjackets are great), and refrigerant. It all depends how vested you want to be in AC work. Not looking to buy all the stuff? Take it to an AC shop. It'll definitely be faster and cheaper in the long run.

Once you know your system holds and there are no leaks, the most accurate way to charge the system is to charge by WEIGHT. Buy a digital scale so you know EXACTLY how much refrigerant you're putting in. I run R12 and have a 30# jug so it makes it much easier to introduce the proper amount of refrigerant without the possibility of putting air in the system. Air = condensation in the system = water in the system = rusting your system from the inside out and poor AC performance. Not only does vacuum check the system for leaks but it boils off the moisture inside the system by reducing atmospheric pressure and drying everything out. Proper charge amount, making clean connections without dirt, and no moisture are all key.

Again, I think it's so much easier to start from ground zero and then you take all of the "is it charged too much? Is it charged too little? Is it a dirty orifice tube?" guesswork out of the equation. And if you've been putting the cans that have leak sealant in them, you'd most definitely want to flush the system too. And that would be another thing to purchase: AC flush kit with solvent and an air compressor to pressurize the kit. But even if you didn't use the leak sealant cans, you'd still want to flush your system in your case when you have it all opened up.

If it's all done correctly the first time, the AC system in the DeLorean will be trouble-free for YEARS. Just like in a brand new car and whether you're running R12 or r134a.

[81dmc]

I changed my radiator and have the same problem. I believe the culprit would be the connections to the condenser.

[Morpheus]

If it were me, I would first pull a vacuum on the system, let it sit, and see if you have any leaks. If so, check your lines and hoses for tightness, maybe even check/replace seals, and start again. But that is only if you feel confident.


My buddy Dmage (Derek) has a vacuum and set of gauges that I can borrow. I think I will give that a shot. Do I need to evacuate the system before I vacuum?


Are you getting power at the compressor? I had the curled red wire break inside the connection to the cars connection and it looked like it was connected when it was not. I metered it and was getting power I just had to fix the lead. We can checked on my gauges when you make it down if you want. Also, I think I have an extra new accumulator laying around in the box if it comes to that.

Thanks, Booby. We can look at it more this weekend.


Are you testing the pressure at rest or with the compressor jumped or cycling?

No, just turned the AC on full blast. It was cycling as I added the freon, but now it will not.


Are your hoses original?

Yes.


If you end up replacing the condenser, most of them will come as a kit with the accumulator and orifice tube. If you change out hoses and accumulator be extra careful on the connections especially the ones connecting to the evaporator - you don't want to complicate things even more by adding dash removal to replace an evaporator with a broken connection.

Understood. Thanks!


The best place to start with where you're at would be to evacuate the system and start from there. Pull your orifice tube, examine it, and replace it anyways since it's a cheap part. You can definitely convert your setup to a later-style accumulator which crosses over to a 1984 Corvette, I believe. The AC system was designed by Harrison Radiator which is now owned by GM but it's basically a GM-based system. Not very tricky.

With AC systems, I've found it to be much easier to start at level one with an empty system and go from there. Once you get all the new parts and your accumulator conversion purchased and installed, replace all the seals (Pep Boys has those, too), pull a vacuum on the system and make sure it holds. True, a vacuum would be second best to charging the system with dry nitrogen when it comes to finding leaks but I've found vacuum to be highly effective and much more practical when it comes to having the right equipment. An AC vacuum that's pretty darn good can be purchased at Harbor Freight for about $90. Which brings me to my next point.

AC work is all about having the right equipment. You'll need a vacuum, GOOD gauges (yellowjackets are great), and refrigerant. It all depends how vested you want to be in AC work. Not looking to buy all the stuff? Take it to an AC shop. It'll definitely be faster and cheaper in the long run.

Once you know your system holds and there are no leaks, the most accurate way to charge the system is to charge by WEIGHT. Buy a digital scale so you know EXACTLY how much refrigerant you're putting in. I run R12 and have a 30# jug so it makes it much easier to introduce the proper amount of refrigerant without the possibility of putting air in the system. Air = condensation in the system = water in the system = rusting your system from the inside out and poor AC performance. Not only does vacuum check the system for leaks but it boils off the moisture inside the system by reducing atmospheric pressure and drying everything out. Proper charge amount, making clean connections without dirt, and no moisture are all key.

Again, I think it's so much easier to start from ground zero and then you take all of the "is it charged too much? Is it charged too little? Is it a dirty orifice tube?" guesswork out of the equation. And if you've been putting the cans that have leak sealant in them, you'd most definitely want to flush the system too. And that would be another thing to purchase: AC flush kit with solvent and an air compressor to pressurize the kit. But even if you didn't use the leak sealant cans, you'd still want to flush your system in your case when you have it all opened up.

If it's all done correctly the first time, the AC system in the DeLorean will be trouble-free for YEARS. Just like in a brand new car and whether you're running R12 or r134a.

Very good advice, thanks. I think I will start with purging and vacuuming the system and go from there.

[dn010]

The system will need to be empty prior to vacuuming.

One thing I don't think was mentioned is the amount of oil in your system as well - if you add R134 with oil your essentially overloading it with too much oil to be efficient. If you change a few components that may have oil in it then you'll never know how much you truly have which will also lead to problems. The last time I did my AC I changed all components aside from the compressor which I drained and refilled so I knew how much I had so that may be something to look into. I too am working on my A/C, I'm just waiting for a condenser to arrive - great time to do it as it's not a million degrees out yet!

Also, original hoses will leak R134 over time.

[DMCVegas]

The system will need to be empty prior to vacuuming.

One thing I don't think was mentioned is the amount of oil in your system as well - if you add R134 with oil your essentially overloading it with too much oil to be efficient. If you change a few components that may have oil in it then you'll never know how much you truly have which will also lead to problems. The last time I did my AC I changed all components aside from the compressor which I drained and refilled so I knew how much I had so that may be something to look into. I too am working on my A/C, I'm just waiting for a condenser to arrive - great time to do it as it's not a million degrees out yet!

Also, original hoses will leak R134 over time.

http://cdn.meme.am/instances/400x/56990095.jpg

Evacuating is basically emptying the entire system of refrigerant by vacuuming it out, and then storing it for reuse later. This is opposed to simply venting the gas out to the atmosphere which is very bad for the environment.

Once all of the gas is out you can safely service your A/C system. I say safely, because if you've ever turned a can of computer duster upside down and sprayed it out, you know that it can freeze things. That's a tiny stream and it can cause real, actual frostbite on human skin. But those are only patches. Now try several POUNDS of refrigerant spraying out and on to your hands or face. That is why when connecting everything, you want to ensure that you're wearing leather gloves and face protection.

Anyhow, moving on...

Once the system is evacuated you can perform work. Replace components, fittings, seals, you name it. A big one is of course your receiver/dryer. Anyway, once the work is complete you will pull a vacuum on the system, and hold it steady for a period of time. This accomplishes to big things:

First, it removes all of the moisture from within the system. Atmospheric air of course has humidity. When you pull a vacuum the pressure inside becomes so low that the water molecules in the air will boil and turn into steam at ambient temperatures. Steam is of course a gas, and so the steam exits out of the system through the vacuum you're pulling.

Second, after vacuuming and reaching a certain pressure, you will then close the valves and let the car sit for a certain period of time to ensure that the car holds it's low pressure. The reason is simple: If the pressure goes up, they you know you've got a leak. Doesn't matter if it's R12, R134a, or even HFO-1234yf. You don't want to just dump the stuff out into the atmosphere. Also, it gets expensive just wasting the stuff. So if you've got a leak, the refrigerant gas is just going to escape and cost you more money. Pulling a vacuum first is crucial to verifying that your system is sealed and has no leaks.

Now if I were you, and you came this far, I'd flush your A/C system out. Not difficult at all. In fact, here's a good example of how you do it:


https://www.youtube.com/watch?v=Lnu8hA9F9S4

Now with a DeLorean that we're converting to R134a, flushing is pretty simple. Remove the Dryer & Orifice tube, and throw them away. Then just disconnect the hoses and flush out your Evaporator and Condenser. Why?

Because you need new hoses! R134a does indeed require a special Barrier Hose. The term "barrier hose" is a bit of a catch-all, but in essence what it means is a certain type of hose that has an inner liner. Pure rubber hoses are porous (think of how balloons deflate by themselves) and will let R134a seep out. R12 molecules are larger and didn't have this problem. So if you're going to convert over to R13a, you're gonna want to replace those hoses, or else you'll just be recharging your system again and again... You'll also need to adjust your high pressure switch a bit since the gasses have different properties, but that's a separate discussion.

If you do need to install the hoses, don't fret. Installing replacement hoses is supposed to be a pain, but there are shortcuts. You can have the hose pushed through between the body and the frame BEFORE you crimp the ends, and you won't have to lift the body and chassis. Either you can do this, or an A/C shop can do it for you.

Personally, after 35 or so years, it's probably best to start from scratch on this system and get it sorted out.

[David T]

The way the whole process starts is to put a manifold gauge set on the system and monitor the system pressures. What you find determines the next steps. If you do not understand how A/C systems work and the procedures used to diagnose and repair them, even if you can get the equipment, you should not be working on it. There are certain dangers involved if you do not know what you are doing.

[Morpheus]

The way the whole process starts is to put a manifold gauge set on the system and monitor the system pressures. What you find determines the next steps. If you do not understand how A/C systems work and the procedures used to diagnose and repair them, even if you can get the equipment, you should not be working on it. There are certain dangers involved if you do not know what you are doing.

I get what you are saying David.

Which is why i'm going to post what my pressures are once I get the gauges hooked up, so I can pick all your brains some more.

[opethmike]

Definitely listen to The Guru. He has an amazing mustache. Much like Samson, if he were to lose it, he would lose all of his Guru-ing prowess.

[Nicholas R]

Gents,
Let's hypothetically say that I have to open up the system to replace one or more components. It is my understanding that when you do so, you should replace a few things automatically, such as the accumulator, orifice tube, and o-rings. That said, must I stay with the "early style" accumulator? I'm not sure if they are even available anymore. Furthermore, if I have to change that, I'm probably going to need new hoses and compressor as well. If i'm leaking at the condenser, then I'm looking at a new one of those now too.

I need guidance.

To answer this specific question, if you open the system up, you do not have to stick with the early style accumulator IF you also change the lines in the process. I too have an early car, and a couple years ago I changed out my lines and accumulator. I purchased the later style lines instead of the early style lines, which allowed me to change to the later style accumulator. I definitely recommend it. The early accumulator is practically $150 now, where the later style can be bought at autozone for about $15. If for no other reason, take that $135 difference in price, and buy new lines with it, instead of spending it on a rare, outdated part.

I'm actually planning to change from R-12 to R134 soon also, and will need to replace the accumulator in the process. I am already thanking myself from several years ago, that this time around I can get away with the cheaper part. Thanks me! :wink:

[Bitsyncmaster]

To answer this specific question, if you open the system up, you do not have to stick with the early style accumulator IF you also change the lines in the process. I too have an early car, and a couple years ago I changed out my lines and accumulator. I purchased the later style lines instead of the early style lines, which allowed me to change to the later style accumulator. I definitely recommend it. The early accumulator is practically $150 now, where the later style can be bought at autozone for about $15. If for no other reason, take that $135 difference in price, and buy new lines with it, instead of spending it on a rare, outdated part.

I'm actually planning to change from R-12 to R134 soon also, and will need to replace the accumulator in the process. I am already thanking myself from several years ago, that this time around I can get away with the cheaper part. Thanks me! :wink:

+1
Most people also think you can dry the accumulator by leaving it on a vacuum for a long time (I was one of those that also thought that). It does not work like that, you need to heat the Desiccant to at least 250 deg. F to dry it. Since there is oil in a used accumulator, you would not want to heat a used one.

[Morpheus]

To answer this specific question, if you open the system up, you do not have to stick with the early style accumulator IF you also change the lines in the process. I too have an early car, and a couple years ago I changed out my lines and accumulator. I purchased the later style lines instead of the early style lines, which allowed me to change to the later style accumulator. I definitely recommend it. The early accumulator is practically $150 now, where the later style can be bought at autozone for about $15. If for no other reason, take that $135 difference in price, and buy new lines with it, instead of spending it on a rare, outdated part.

I'm actually planning to change from R-12 to R134 soon also, and will need to replace the accumulator in the process. I am already thanking myself from several years ago, that this time around I can get away with the cheaper part. Thanks me! :wink:

Since early cars don't have the "hub" assembly and the High pressure switch, I don't need that either correct? This is what I'm talking about:

39775

So, new hoses, accumulator, orifice, and possibly condenser. Possibly even new compressor. This is getting expensive.

[David T]

Since early cars don't have the "hub" assembly and the High pressure switch, I don't need that either correct? This is what I'm talking about:

39775

So, new hoses, accumulator, orifice, and possibly condenser. Possibly even new compressor. This is getting expensive.

If you still have the original hoses they must be replaced at a minimum. If the insides are not contaminated you will also need an accumulator/dryer and replace all of the "O" rings. The oil should also be replaced and the system flushed. If the insides are coated with black goo you could wind up having to replace everything. Since your system was converted that is a possibility.

[Bitsyncmaster]

Since early cars don't have the "hub" assembly and the High pressure switch, I don't need that either correct? This is what I'm talking about:

39775

So, new hoses, accumulator, orifice, and possibly condenser. Possibly even new compressor. This is getting expensive.

The hub lets the high pressure switch and overpressure valve get mounted near the accumulator. Some people mount those at the condenser.

[Morpheus]

Ok kids, here's an update:

I went over to my buddy's house to borrow his gauges and vacuum pump, and while he was showing me how to hook it up, we noticed that the high side port was angled strangely, and actually loose. Like, it moved when we touched it loose. I think I might have found my leak. Considering all the work I was recently doing on the engine, it's feasible that I knocked the fitting loose, or it was just slightly loose all along and leaking out slowly all this time.

So, as my system was evacuated because of a loose service port, I got home, tightened both ports down, and hooked up the vacuum pump. I let it pull vacuum for a couple of hours, closed both high and low side valves, and disconnected the vacuum pump. The gauges read 30 inHg like this:
39785

So, I will let it sit like this overnight. If it holds, can I assume my leak is fixed? If so, all I should need to do now is put in about 36oz of R134A and I should be good for a good while, correct?

I'll just need to know what the gauges should read when the system is full and hopefully this issue can be resolved.

[Nicholas R]

Since early cars don't have the "hub" assembly and the High pressure switch, I don't need that either correct? This is what I'm talking about:

39775

This is up to you. If you add it, you will have to wire up the high pressure switch to turn off the clutch when the switch is triggered (not sure if its NO or NC). I did not add it when I swapped mine out. The only change I made was the later style line to allow me to use the later style accumulator.

[kings1527]

Ok kids, here's an update:

I went over to my buddy's house to borrow his gauges and vacuum pump, and while he was showing me how to hook it up, we noticed that the high side port was angled strangely, and actually loose. Like, it moved when we touched it loose. I think I might have found my leak. Considering all the work I was recently doing on the engine, it's feasible that I knocked the fitting loose, or it was just slightly loose all along and leaking out slowly all this time.

So, as my system was evacuated because of a loose service port, I got home, tightened both ports down, and hooked up the vacuum pump. I let it pull vacuum for a couple of hours, closed both high and low side valves, and disconnected the vacuum pump. The gauges read 30 inHg like this:
39785

So, I will let it sit like this overnight. If it holds, can I assume my leak is fixed? If so, all I should need to do now is put in about 36oz of R134A and I should be good for a good while, correct?

I'll just need to know what the gauges should read when the system is full and hopefully this issue can be resolved.

If the leak is fixed, that's a great place to start. But your system has still been sitting at atmospheric for who knows how long. At a minimum, you'll still need to replace the accumulator and it's still good practice at this point to pull the orifice tube and replace it, flush the system, add oil to it (including directly into the accumulator during installation...I want to say the accumulator holds around 1oz at any given point in time), and then charge the system. If your system isn't up to par before you add refrigerant, eventually it will become contaminated and you'll get poor performance. With an empty system, there's several things can do to make life easier for down the road and keep your performance solid for a long time.

[Bitsyncmaster]

Yes it looks like you found one leak. I would do as you suggest and charge it. Probably will work fine with two cans of R134 but I usually charge about 2.5 cans. Your high pressure gauge usually tells you when to stop charging but a lot depends on the air temp and how much air is passing over the condenser. I would stop charging if the high side starts going over 250 PSI.

With your system working, it will tell you how long it will last and if you should do more work later. I found I needed a new hose on my car since it only held for 3 to 4 months.

[Morpheus]

This is up to you. If you add it, you will have to wire up the high pressure switch to turn off the clutch when the switch is triggered (not sure if its NO or NC). I did not add it when I swapped mine out. The only change I made was the later style line to allow me to use the later style accumulator.

If it's not necessary, I'm not going to add wiring for the heck of it. I'll follow your lead on this one.

[David T]

Holding vacuum is OK but you can't read a hard vacuum on a manifold gauge. To find leaks you pressurize the system with Nitrogen to 150 psi and check with bubbles. A vacuum is only 15 psi negative and it will pull in contaminants, not a good way to look for small leaks. I would replace the seal on the high side hose that was loose. That gets the most heat and pressure and the "O" ring gets hard. If you can hold 150 psi THEN you change the oil and vacuum the system.

[Morpheus]

Thanks again for all the advice gentlemen.

When I got home last night, the needle on the gauge hadn't moved which means the system held vacuum for 18 hours. I put in 3 cans of R134 (of which, about 2.5 cans worth probably made it in) and some dye. Shone a UV light around each connection point and did not observe any leaks. Air was blowing ice cold.

This morning, I fired the car up again and tested. Air is ice cold again, no leaks.

It's safe to say at this point that the leak point was indeed the valve on the High Side at the back of the compressor. Once that was tightened down, it seems to have solved the issue for now. And that's all I needed really: a quick temporary fix to get me through the weekend and perhaps for another month or so. I am keenly aware that this is simply a temporary band-aid solution, and that my system does require further attention.

My plan now is to eventually replace all hoses with newer barrier hoses, change the accumulator to the newer style, new orifice tube & o-rings, new condenser, and new compressor. I can slowly start acquiring these parts over the next few months and hopefully get the system redone before the brutal summer begins.

[bfloyd]

So, I'm about to tackle this myself since riding around in the car in the southeast is like driving an easy bake oven. My intention is to just go ahead and covert the whole thing to R134, which from reading the forums here, I'm looking at basically replacing the entire system?

New compressor, hoses, accumulator, condenser, etc. Does the evaporator automatically need replacing or what? My plan is to buy the parts and have the local mechanic install them.

Am I missing anything?

[dn010]

Don't forget a new orifice tube. Try (or have your mechanic try) to remove your accumulator first, you may need a new evaporator anyway depending on how that goes. Also I did not replace my compressor or condenser back when I first converted my system. I flushed everything out and used Ester oil in the compressor.

[David T]

Even in a moderate climate it is impossible to drive the car without A/C. Usually you can get by by replacing the 3 hoses and the accumulator/dryer if the insides of the system are still clean. Best to try to stay with R-12 if you can. You only need a small amount of it and even though it is expensive, considering what you will be spending on parts and labor, it won't increase the cost much. If your shop doesn't want to get the R-12 you can buy it on the Internet and give it to him to use along with the parts.

[cdrusn]

So, I'm about to tackle this myself since riding around in the car in the southeast is like driving an easy bake oven. My intention is to just go ahead and covert the whole thing to R134, which from reading the forums here, I'm looking at basically replacing the entire system?

New compressor, hoses, accumulator, condenser, etc. Does the evaporator automatically need replacing or what? My plan is to buy the parts and have the local mechanic install them.

Am I missing anything?


Why would you want to replace the entire system just to swap over to R134? The only thing you really have to do is dump out the old oil from the compressor (take it off and open the screw on top and dump). Put new green O rings (harbor freight) on the high and low side connections. Put 8 ozs. of Pag 46 oil in the compressor, 2 cans of R134 and enjoy the a/c. Your accumulator, evap, condenser and hose will do fine without changing anything. You don't want to make the system worse by changing out the evaporator and accumulator nor do you want to pay an overpriced a/c technician $1000 for $100 worth of work. Vacuum the system, hook up your harbor freight gauges and add Freon to about 40" on the low side suction. Most people look at a/c as black magic but it just makes sense, besides with Freon going for $5 a can you can afford to make some mistakes before you get a tight system.:race:

[content22207_2]

I recommend Ester oil over PAG. Ester is compatible with residual mineral oil. PAG has a reputation of reacting badly with any mineral oil (or mineral spirits if you use that as a flushing agent) still in the system to produce "black death" -- a gooey black substance that can clog things up.

Bill Robertson
#5939

[dn010]

At the very least you should still change your accumulator and orifice tube. If you're going to use the original hoses, they will leak R134 so you'll have to recharge it whenever it gets low enough to stop working. If it were me, I'd do it once and do it right (even at $5/can), and enjoy the years to come driving around with nice cold air and without having to add refrigerant or repair something in the system.

When you try removing the accumulator, IF you find your lines beginning to bend or your fittings are frozen, get some R12 and leave it alone for the summer - replace the accumulator and evaporator, lines etc when it is winter.



Why would you want to replace the entire system just to swap over to R134? The only thing you really have to do is dump out the old oil from the compressor (take it off and open the screw on top and dump). Put new green O rings (harbor freight) on the high and low side connections. Put 8 ozs. of Pag 46 oil in the compressor, 2 cans of R134 and enjoy the a/c. Your accumulator, evap, condenser and hose will do fine without changing anything. You don't want to make the system worse by changing out the evaporator and accumulator nor do you want to pay an overpriced a/c technician $1000 for $100 worth of work. Vacuum the system, hook up your harbor freight gauges and add Freon to about 40" on the low side suction. Most people look at a/c as black magic but it just makes sense, besides with Freon going for $5 a can you can afford to make some mistakes before you get a tight system.:race:

[Andrew]

At the very least you should still change your accumulator and orifice tube. If you're going to use the original hoses, they will leak R134 so you'll have to recharge it whenever it gets low enough to stop working. If it were me, I'd do it once and do it right (even at $5/can), and enjoy the years to come driving around with nice cold air and without having to add refrigerant or repair something in the system.

When you try removing the accumulator, IF you find your lines beginning to bend or your fittings are frozen, get some R12 and leave it alone for the summer - replace the accumulator and evaporator, lines etc when it is winter.

Normally, I would agree with the accumulator replacement; however, due to the location of the DeLorean accumulator and evap inlet pipe (both have significant exposure to the elements in the wheel well.) there is a substantial risk of breakage of the fittings upon removal. To make matters worse, the close proximity of the evap lines to the gas tank makes the use of the "orange wrench" downright dangerous. 5052's accumulator sheered off in the fitting of the low side hose, so far that was the only seized connection on 5052...which was an 11,500 mile Texas / Oklahoma car. I was able to get a replacement barbed low side hose fitting at my local A/C repair shop. After the difficulty I had with the accumulator, I decided to leave the orifice tube fitting alone. Frankly I'm glad I did, as the stock orifice tube is delivering 40-44 degree vent temps :-)

The attempted replacement of 1 A/C part can easily turn into a replacement of multiple components or even the entire system due to seized fittings. In addition to the difficulty of replacing the low side hose if necessary, an evap coil is a PITA to replace. Furthermore, the stock serpentine condenser is much better than the tube and fin style replacement that is available. However, as documented on other posts a universal parallel flow in the correct size is better than the tube and fin. If your system is otherwise in good shape, I would recommend starting off with replacement of the compressor oil with ester oil, replacement of the compressor gaskets and adjust the low pressure switch to cut off at around 22 PSI.. 1/2 a turn CCW should do it. Charge it up with 2 pounds of 134a and enjoy a cold car. Since R134a is really cheap these days (Wal-Mart is selling 12 oz cans for less than $5.00...Furthermore, Sam's Club is selling 30 pound tanks for less than $70!) the occasional top-off will be much cheaper than replacing the entire system.

[David T]

If the system has been "atmospheric" for a long time you really need to replace the accumulator/dryer. With the proper tools and some patience you should be able to undo the fittings without damaging the lines. The orifice tube is another story. If the inside of the lines looks clean you should leave it alone. It was placed into the line and the line was then bent so the evap coil could be installed. It is near impossible to get that orifice tube out without destroying it and possibly the soft tube it is installed in. Rob Grady told be about how he melts them out. The hoses and seals have aged to death like tires so they have to be replaced. Replacing the oil is just good practice. As for staying with R-12 or going to some other type of refrigerant, even though R-12 is expensive, you don't need much and the system was designed to work with it, any other refrigerant will not work as well. The newer barrier type hoses should leak less and last longer. Even if you have to "top off" your system once a year with less than 1/4 lb, small price to pay for cool air. Once it gets over 70 degrees and is sunny you can't drive a Delorean without A/C!

[Morpheus]

Rather than start a new thread, I will just resurrect my old one to ask a few questions...

The pulley seal on my stock compressor is leaking, the evidence of which is a fine line of oil spattered on the underside of my engine cover, coolant hose and water pump. I'm guessing that this seal is replaceable, but for the effort involved it's likely better to replace the compressor. Am i correct in this assumption?

After a few conversations with Henrik, I have decided to purchase a new, more modern and efficient model to replace my stock unit: the Sanden SD7H15. Warning, large pic alert.
http://store.sanden.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/4/7/4708.jpg

My next question is related to new A/C hoses. Obviously, barrier hoses are the answer here. After researching this, I have found 3 possible solutions:

Hervey, $230
Pro: New, factory-made Goodyear hoses with a 5 year warranty suitable for R134a. Reasonably priced.
Con: Split-hose design. Despite a seemingly large number of satisfied customers with 0 problems, I agree with Dave Swingle's comment in another A/C thread about the future potential of introducing 6 new possible leak points.

DPI, $395
Pro: New, one piece hoses suitable for R134a.
Con: Pricey. Also, the whole crimp-it-yourself thing is a bit off putting for me. I'm sure they are a quality product and all, but I don't want my ability as a crimper of hose to be the determining factor between having a leak-free system. No offense, Josh.

DMCH, $425? (Cost of all 3 NOS hoses)
Pro: For NOS, none. Might as well keep what I have.
Con: Pricey?

DMCH alludes to selling hoses for R134a on their site; when you pull up a NOS hose, at the top it reads "Original R12 hose - also suitable for RedTek. Not for R143 systems - see 100750A." If you search for that number on their site, you get referred back to the original NOS part. So, do they or don't they?

Is there another option for R134a hoses available that I'm not aware of? I'd like to keep the hoses one piece AND made for R134a.

[FABombjoy]

Also, the whole crimp-it-yourself thing is a bit off putting for me.
Have you watched the assembly videos? It's a piece of cake!
https://www.youtube.com/watch?v=uKExoJPH9NQ

https://www.youtube.com/watch?v=pN8906gP1wU

[content22207_2]

FWIW:

44270

Hasn't leaked yet....

Bill Robertson
#5939

[Henrik]

Rather than start a new thread, I will just resurrect my old one to ask a few questions...

The pulley seal on my stock compressor is leaking, the evidence of which is a fine line of oil spattered on the underside of my engine cover, coolant hose and water pump. I'm guessing that this seal is replaceable, but for the effort involved it's likely better to replace the compressor. Am i correct in this assumption?

That's right, Brandon. I recommend addressing that leaky shaft seal before the compressor clutch's wear surfaces get coated with oil; when/if that happens the slipping clutch will overheat and potentially cause all sorts of damage.

As far as serviceability, the SD-510 is no longer in production so finding the (so called) mechanical seal (as opposed to the SD7's lip seal), you are likely not going to find the parts or tools you need. I looked at Sanden's SD7/SD5 service manual (http://www.sanden.com/servicemanual.html); it covers all service aspects of the compressor but it does not cover shaft seal replacement. It does list the SD7's lip seal tool at the end but as far as the 510: No mention of how to replace the seal or what the tool would (or rather, used to) look like.

Long story short - replace that pump!

[Morpheus]

Have you watched the assembly videos? It's a piece of cake!
https://www.youtube.com/watch?v=uKExoJPH9NQ

https://www.youtube.com/watch?v=pN8906gP1wU

Those videos DO make it look easy. So I take it these hold up well over time? Has anyone (that has gone this route) had any issues?

[Morpheus]

That's right, Brandon. I recommend addressing that leaky shaft seal before the compressor clutch's wear surfaces get coated with oil; when/if that happens the slipping clutch will overheat and potentially cause all sorts of damage.

As far as serviceability, the SD-510 is no longer in production so finding the (so called) mechanical seal (as opposed to the SD7's lip seal), you are likely not going to find the parts or tools you need. I looked at Sanden's SD7/SD5 service manual (http://www.sanden.com/servicemanual.html); it covers all service aspects of the compressor but it does not cover shaft seal replacement. It does list the SD7's lip seal tool at the end but as far as the 510: No mention of how to replace the seal or what the tool would (or rather, used to) look like.

Long story short - replace that pump!

Am I also right in assuming that leaky shaft seal = losing freon as well? I have noticed a reduction in cooling ability as of recent.

[David T]

PJ Grady also sells hoses and his ends at the compressor come off so they can be installed easily. Replacing the compressor is the way to go, no way to tell if the new seal you get will also leak! Be careful with the new one, make sure it has enough of the proper oil in it. Some come dry and some have -134 oil in them. A leaking shaft seal means you lose oil AND refrigerant. I do not recommend field crimping unless there is no other way. You are dealing with HIGH pressures and if you don't do it exactly right the fittings can blow off. Also if you do not index the fittings correctly and put any twist on the hoses it will shorten the life of the hose.

[Henrik]

Am I also right in assuming that leaky shaft seal = losing freon as well? I have noticed a reduction in cooling ability as of recent.

Correct.

[Henrik]

make sure it has enough of the proper oil in it. Some come dry and some have -134 oil in them.

During my years at Sanden, we never shipped dry compressors, and I do not believe that has changed. And once R134a became the de facto industry standard - in the mid 90s - we always shipped it with SP-15, i.e. "134 oil".

BTW, the type and amount of oil shows right on the compressor's label: http://dmctalk.org/showthread.php?13230-Uh-oh-A-C-not-blowing-cold&p=200761&viewfull=1#post200761

[David T]

During my years at Sanden, we never shipped dry compressors, and I do not believe that has changed. And once R134a became the de facto industry standard - in the mid 90s - we always shipped it with SP-15, i.e. "134 oil".

BTW, the type and amount of oil shows right on the compressor's label: http://dmctalk.org/showthread.php?13230-Uh-oh-A-C-not-blowing-cold&p=200761&viewfull=1#post200761

Often parts like A/C compressors are shipped "dry" because some shippers are very fussy about packages dripping oil. In any case good practice would be to check that it has oil in it BEFORE you try using it! It won't last very long at all if it IS dry. If you go to the Sanden website there are instructions on how to make a dipstick and in the Workshop Manual it tells you how to measure the oil level.

[Henrik]

Often parts like A/C compressors are shipped "dry" because some shippers are very fussy about packages dripping oil. In any case good practice would be to check that it has oil in it BEFORE you try using it! It won't last very long at all if it IS dry. If you go to the Sanden website there are instructions on how to make a dipstick and in the Workshop Manual it tells you how to measure the oil level.

I give up...

[FABombjoy]

Those videos DO make it look easy. So I take it these hold up well over time? Has anyone (that has gone this route) had any issues?
I'm about to install this system over the next week with a new compressor, dryer, and condenser. In hand all parts seem quality and there isn't much negative about it on the internet. I like that it will be easy to index and crimp once the hoses are routed to keep the connectors as stress free as possible.

[Morpheus]

I'm about to install this system over the next week with a new compressor, dryer, and condenser. In hand all parts seem quality and there isn't much negative about it on the internet. I like that it will be easy to index and crimp once the hoses are routed to keep the connectors as stress free as possible.

I look forward to seeing your results! Will you be posting pics of the process?

[FABombjoy]

I look forward to seeing your results! Will you be posting pics of the process?
I'll try to take some as I go. I have a bunch of stuff before DCS and its a bit like cramming for an exam!

[DMC5180]

I'm about to install this system over the next week with a new compressor, dryer, and condenser. In hand all parts seem quality and there isn't much negative about it on the internet. I like that it will be easy to index and crimp once the hoses are routed to keep the connectors as stress free as possible.

You and me both, I've just completed the line replacement. The new lines are 2/3 rds the diameter of the originals (modern technology). As far as installing the ends it doesn't get much easier. Plus if you need to go back adjust the fitting rotation to remove twist loading, you can do that by unclipping the rings. Reset the fitting position and re-clip the rings. Also fishing the lines through the frame channels is very easy. Tip : loop a tie-wrap around the hose close to the end (don't cut the tail) now you have a little handle that will stick out of the narrow slot between the frame and underbody. Now you push the with one hand and guide it along with the other use the tie-wrap tail to guide the hose end around any snags. Easy-peezy.

For me push/pulling the old the 35 year old stiff hoses was a pain in the butt. I cut the rear fittings off and pulled all the hose out the front.

I went with condenser flushing vs replacement. New accumulator and cleaned my VOV oriface tube.

This afternoon A new SD7H15 (4708) w/ QD head will go on. One thing to note, I had to replace the original QD head with one has the relief valve port because the system is being upgraded to the later style configuration (no more HUB hose).


Dennis

[bfloyd]

I just ordered the complete system replacement (hoses, fittings, accumulator and compressor) from DPI this afternoon. Besides flushing the condenser, is there any other things I should be looking at while I'm in there?

I noticed that the existing accumulator I have on the car looks a little different than the one that's coming with this kit. Mine has a fitting coming off the bottom,. whereas this new one does not. Since I'm replacing all of the hoses and fittings as well, is this even an issue?

[Morpheus]

I just ordered the complete system replacement (hoses, fittings, accumulator and compressor) from DPI this afternoon. Besides flushing the condenser, is there any other things I should be looking at while I'm in there?

I noticed that the existing accumulator I have on the car looks a little different than the one that's coming with this kit. Mine has a fitting coming off the bottom,. whereas this new one does not. Since I'm replacing all of the hoses and fittings as well, is this even an issue?

No. If you are replacing the hoses, then they will be the correct length for the new style accumulator.

In addition to replacing the parts you listed, I have been advised by some to also replace the condenser with a parallel flow type, which is better for R134a. Houston sells this now instead of OEM.

[DMC5180]

Can you Post a visual of parallel vs OEM? I think mine is parallel ( 2 rows of copper tube going side to side). I think OEM is 1 row flat tube folded like ribbon candy.


Dennis

[Morpheus]

The DMCH page shows a NOS consenser, so it's not of much help.

http://store.delorean.com/p-7716-condenser-includes-accumulatordrier-orifice-tube-and-o-rings.aspx

Hervey's website has a picture of a parallel flow condenser:
http://specialtauto.com/delorean-parts/images/ac-condenser.jpg

[FABombjoy]

I'm going to give the CN20010XC universal parallel flow a shot. Slightly shorter than OEM but only $55.

I scratched up the inside of the evaporator inlet while removing the orifice valve but I think I've smoothed things out enough to make it work again. I straightened the inlet tube out enough that hopefully I can seat the new valve just a hair further into the tube and avoid the damaged spot.

Whole lotta variables going on here before making the 800 mile round trip to DCS!