A/C Test nad diagnosis

[alexwolf1216]

Now that my brakes are done, the next item I want to tackle is the AC system. Its HOT in Texas, and I dont want to wait until winter to drive this thing.....I read through a buch of threads including Alex's detailed replacement thread, which was a little over my head. I saw something about jumpering the compressor to see if it powers, but I couldnt find any instructions on how to do that. My blower works fine, and I hear the vacuum when it first starts up. So, my questions:

1.) How do I jumper the compressor?
2.) Where do I start to see what the problem might be? Would this be to put dye in or soap and check for leaks? Is this something I can have an AC shop do just for diagnosis?

I really dont want to replace everything if I dont have to....it seems like a TON of work and some of it looks a little complex, like jacking the body off the frame to get the hoses in.

[Kevin]

You've confirmed your compressor isn't cycling on, correct? You can tell if the center of the compressor is spinning or not. If it's not, it's either not getting power due to low pressure or electrical fault, or the clutch coil is bad.

To jumper the compressor, disconnect the compressor at the connector, should be right by the compressor covered in some protective rubber, just pull it out and that should expose the metal. Then find a 12v source, such as the positive battery terminal in the engine bay, and touch a wire between the two. If the clutch engages, your compressor should be fine.

If the compressor seems fine, you need to figure out why it's not getting power normally. Next place to check is the low pressure switch on the accumulator. The accumulator is the cylindrical thing by your right front tire, the low pressure switch has two wires coming out. Unplug it, ensure you're getting 12v at one of the two wires when the A/C is switched on. If that looks good, test resistance across the low pressure switch on the accumulator, you should get 0 ohms if you have enough pressure in your system. If you get lots of resistance or an open, you either have low refrigerant or a bad low pressure switch (just happened to me last week). It's really convenient to have a set of manifold gauges in this case to confirm you have enough refrigerant so you're not chasing down an electrical or mechanical problem when you had low refrigerant all along, so I'd recommend a way to check pressure if you can just to eliminate that variable.

If you find you have a leak, then yes you could put dye into the system or you can use a leak detector around the connections. If you're using R-134a with the original hoses, it could be leaking out through the hoses since R-134a molecules are smaller than R-12 and can seep out of hoses if they're not barriered with nylon.

[alexwolf1216]

Kevin,

Thanks for the reply. I have not confirmed yet. I havent even breached the subject yet. As soon as I get the angle drive Monday I will get her running and check out the compressor in better detail. It looks like getting the gauges is a good idea either way, so I will probably just pick some up. The car sat for 25~ years, so no clue what could be the problem.

[David T]

Kevin,

Thanks for the reply. I have not confirmed yet. I havent even breached the subject yet. As soon as I get the angle drive Monday I will get her running and check out the compressor in better detail. It looks like getting the gauges is a good idea either way, so I will probably just pick some up. The car sat for 25~ years, so no clue what could be the problem.

The most likely reason you have no A/C is that the refrigerant leaked out and the low pressure switch is preventing the compressor from running. The first step is to get a set of gauges on the system. Once you confirm the pressure is low you need to find and fix the leaks. That usually means replacing the 3 hoses, all of the seals, and the dryer/accumulator. Now you remove as much oil as you can from the compressor and replace the oil. Replace the service valve cores. Once you are confident you have all of the leaks fixed you vacuum the system and fill with refrigerant. You may also need to replace the vee belt and the idler pulley bearings. Without all of the specialized tools necessary to do the "finish" work, you can replace all of the parts and let a shop finish up the job of finding any leaks, vacuuming the system, and filing with refrigerant.

[alexwolf1216]

The most likely reason you have no A/C is that the refrigerant leaked out and the low pressure switch is preventing the compressor from running. The first step is to get a set of gauges on the system. Once you confirm the pressure is low you need to find and fix the leaks. That usually means replacing the 3 hoses, all of the seals, and the dryer/accumulator. Now you remove as much oil as you can from the compressor and replace the oil. Replace the service valve cores. Once you are confident you have all of the leaks fixed you vacuum the system and fill with refrigerant. You may also need to replace the vee belt and the idler pulley bearings. Without all of the specialized tools necessary to do the "finish" work, you can replace all of the parts and let a shop finish up the job of finding any leaks, vacuuming the system, and filing with refrigerant.

Letting a shop do the rest doesnt sound like a bad option. I am going through the site now trying to get a comprehensive list of parts. I consider myself a novice on these repairs, but the parts mentioned dont look to be so bad, except the hoses. The evaporator looks to be a bit of a time consuming endeavor.

Alex

[Kevin]

If you end up needing to replace the hoses, you can either try Hervey's:

http://www.specialtauto.com/delorean-parts/AC-Cooling.html

Or contact Josh at DPI and he'll send you Aeroquip hoses (I just did this a couple months ago).

I mention both these sets of hoses because they do not require you to separate body from the frame, and they're ready for R-134a. And yes, the evaporator will be a pain to replace, but you might not have to unless you want to, I'm trying to see how long I can rock my original.

[alexwolf1216]

If you end up needing to replace the hoses, you can either try Hervey's:

http://www.specialtauto.com/delorean-parts/AC-Cooling.html

Or contact Josh at DPI and he'll send you Aeroquip hoses (I just did this a couple months ago).

I mention both these sets of hoses because they do not require you to separate body from the frame, and they're ready for R-134a. And yes, the evaporator will be a pain to replace, but you might not have to unless you want to, I'm trying to see how long I can rock my original.

Josh has been really great to me, so certainly I will get with him. That in depth write up really put me off about the evaporator, unless I have the desire to dismantle half the damn car, which I dont. It did show that the split hoses still didnt fit in between the frame, but that was the Hervey set he used.

Alex

[David T]

Josh has been really great to me, so certainly I will get with him. That in depth write up really put me off about the evaporator, unless I have the desire to dismantle half the damn car, which I dont. It did show that the split hoses still didnt fit in between the frame, but that was the Hervey set he used.

Alex

The split hose set is the way to go. You should not need an evap coil (or a condenser coil) unless you mess up the pipes going to it. That should not happen if you are careful and "back up" with a second wrench and do not twist the pipes. If they are clean inside do NOT try to replace the orifice tube. You should check the system BEFORE you go ordering stuff. If it is all black inside you may have to replace everything. When you do order stuff call and discuss this with the vender, they will help you get what you will need.

[alexwolf1216]

I am not sure what you mean by "back up", but it might be clearer when I start to actually work on it.

[NightFlyer]

The A/C system on my car hadn't worked since the mid '80's, but I recently revived it to fully operable condition without replacing a single component.

1) Disconnect the hoses from the compressor and pull the compressor (I found that it was easier removing the compressor and mounting brackets as an assembly from the valve cover as opposed to trying to remove the compressor from the brackets).

2) Drain the compressor of any oil that might be in it - do this from both the fill hole and hose connection end (I left it sitting in such a position to gravity drain the oil from both locations for 12 hours each, occasionally manually rotating the clutch).

3) Back flush the system by pouring a flushing agent (mineral spirits, lacquer thinner, etc) into the low side hose, and then use compressed air to push the flushing agent through the system and out the high side hose and into a catch contain of some sort. Flush this way multiple times - I used roughly 1.5 gals of my flushing agent.

4) Blow the system out with compressed air until it's relatively dry - do this from both low to high (back blow) and high to low.

5) Fill the compressor with 6oz-8oz of ester oil in the oil fill port only (do not add any oil to the hose connection ports as it's not necessary). Ester will work with whatever type of refrigerant you wish to run in your system - R-12, R-134a, R-152a, 12a product, etc.

6) Reinstall the compressor and the hoses to the compressor. Replace the o-rings on the hose connection ports, or if they appear to be visually ok, you might get away with simply reversing the existing ones.

7) Replace the schrader cores in the service ports with new ones (teflon seal cores are highly recommended, but standard nitrile seal cores will work just fine).

8 ) Pull a vacuum on the system for 1-2 hours, as this will boil out any residual flushing agent and atmospheric moisture that may have infiltrated the system. Then hold the vacuum on your system for 12 hours - this will let you know if you have any major leaks that you'll need to identify and remedy and before charging your system.

9) If the vacuum you pulled in step 8 appears to hold fine for 12 hours, then you're reading to charge the system with your choice of refrigerant. Start the car, set the mode switch to Max or normal A/C, adjust the mixture control all the way to cold, and turn the fan speed to 4. Always charge only on the low side and always charge only as a gas, and not as a liquid. Best way to charge as a gas is to pre-heat your refrigerant container using some hot water. Add the required amount of refrigerant needed to constitutes a full charge of the system: R-12 = 2.2 pounds (35.2oz); R-134a = 1.87 pounds (30oz); R-152a = 1.21 pounds (20oz); etc. The vacuum on the system will instantly pull in several ounces of refrigerant. A few minutes in, and the compressor should start cycling. The close you get to a full charge, the longer the compressor will stay running. Make sure that you don't introduce air into the system during your refrigerant charge.

10) Adjust the low pressure switch if needed based upon the pressure readings obtained from your manifold gauge set.

11) Enjoy your A/C system!

[David T]

What I mean by "back up" is to use two wrenches, one to hold the pipe from turning while using the other to unscrew the connection. I do not recommend using the original hoses. They are leaky and old and if you don't lose all of your refrigerant from leaks they will just blow up and you will lose it all. If you are on a tight budget that is one thing but if you are looking for long term reliability you should replace the hoses and dryer. On a hot, sunny day you can lose a lot of weight driving a Delorean without A/C. And it doesn't take very long!

[DMCMW Dave]

Even with this care you may end up finding that the steel hose fittings have bonded themselves to the aluminum evap or condenser fittings. When that happens you can take all the care in the world and will find the aluminum threads embedded in the steel hose fittings, and you then in line for a component replacement. This is why most evaporators or condensers get replaced, rather than actual holes in the core.

[NightFlyer]

Even with this care you may end up finding that the steel hose fittings have bonded themselves to the aluminum evap or condenser fittings. When that happens you can take all the care in the world and will find the aluminum threads embedded in the steel hose fittings, and you then in line for a component replacement. This is why most evaporators or condensers get replaced, rather than actual holes in the core.

This is exactly why I (and others) recommend trying the system as is first and foremost, without replacing any of the components (hoses included). You've got nothing to lose other than the time it takes to put a vacuum on it and see if it holds or not.

I admittedly screwed up my charging and probably introduced some air into the system, but I'm currently running 48F vent temps in mid 80's ambient temps without having replaced anything in the system (other than the oil and refrigerant).

[David T]

This is exactly why I (and others) recommend trying the system as is first and foremost, without replacing any of the components (hoses included). You've got nothing to lose other than the time it takes to put a vacuum on it and see if it holds or not.

I admittedly screwed up my charging and probably introduced some air into the system, but I'm currently running 48F vent temps in mid 80's ambient temps without having replaced anything in the system (other than the oil and refrigerant).

While it is possible you may damage the fittings taking them apart, sooner or later you have to to either replace the hoses or even just the "O" ring seals to fix the leaks. The hard truth is your old hoses ARE leaky and need to be replaced. Face it, if you didn't have leaks you would still have refrigerant and none of this would be necessary in the first place. Take the fittings apart as carefully as you can. Hey, we have to replace water pumps and no one is saying not to do it because you may break off a few bolts! Sometimes there is "collateral damage". You try to minimize it but no matter how careful you are things go wrong. Most of the time, once you loosen the A/C fittings you can undo the connection with your fingers.

[Bitsyncmaster]

Actually I found all the hose and piping on my AC were very loose. You do not need much torque at all on those fittings. Now if they are corroded then you may have problems.

[NightFlyer]

While it is possible you may damage the fittings taking them apart, sooner or later you have to to either replace the hoses or even just the "O" ring seals to fix the leaks. The hard truth is your old hoses ARE leaky and need to be replaced. Face it, if you didn't have leaks you would still have refrigerant and none of this would be necessary in the first place. Take the fittings apart as carefully as you can. Hey, we have to replace water pumps and no one is saying not to do it because you may break off a few bolts! Sometimes there is "collateral damage". You try to minimize it but no matter how careful you are things go wrong. Most of the time, once you loosen the A/C fittings you can undo the connection with your fingers.

Can't remember what book it was, but I recall reading somewhere that a majority of slow refrigerant leaks from automotive A/C systems are caused by leaky service port schrader valves - not the hoses or even worn o-rings.

Again, you lose nothing other than a little bit of time testing the system as is. If it holds vacuum for over 12 hours, charge it up and see what you get.

If you use R-152a or a 12a product, you can even add a 10oz can to the system every year and not feel guilty about any environmental consequences, as R-152a and 12a products are NOT ozone depleting or global warming refrigerants, unlike R-12 and R-134a. Not to mention that R-152a and 12a products work just as good as R-134a. Not to mention that R-152a can be had for as little as $2.79/10oz can and even cheaper if buying en bulk....

[jawn101]

FWIW, I replaced my whole A/C system stem to stern with the exception of the condenser and evaporator. Condenser would have been a piece of cake with the system open, but it wasn't needed. Evaporator is a bitch, but fortunately not required in very many cases. Split hoses are the way to go for sure - Hervey's were the only option at the time I did mine, but Josh's are beautiful (if expensive)

[NightFlyer]

Actually I found all the hose and piping on my AC were very loose. You do not need much torque at all on those fittings. Now if they are corroded then you may have problems.

The fittings on my accumulator look delicate enough to where I don't even want to try messing with getting them apart if I don't have to (but then again, it could just be all surface rust and easier than pie getting everything apart). Unless I absolutely have to start cracking open those fitting and replacing components though, why not just run what's currently working fine?

Admittedly, your A/C is a good 10F-15F degrees colder than mine is (I really need to redo my refrigerant charging properly - BTW, thanks for reminding me about the hot water trick at the show), but mine prevents me from breaking a sweat and keeps me cool on hot sunny days just fine :)

[David T]

Can't remember what book it was, but I recall reading somewhere that a majority of slow refrigerant leaks from automotive A/C systems are caused by leaky service port schrader valves - not the hoses or even worn o-rings.

Again, you lose nothing other than a little bit of time testing the system as is. If it holds vacuum for over 12 hours, charge it up and see what you get.

If you use R-152a or a 12a product, you can even add a 10oz can to the system every year and not feel guilty about any environmental consequences, as R-152a and 12a products are NOT ozone depleting or global warming refrigerants, unlike R-12 and R-134a. Not to mention that R-152a and 12a products work just as good as R-134a. Not to mention that R-152a can be had for as little as $2.79/10oz can and even cheaper if buying en bulk....

Testing for leaks using a vacuum tells you only that you have no big leaks. You are only testing at negative 15 psi. And if you do have leaks you are only pulling in air with moisture and dirt. The only way to test is to pressurize the system to at least 100 psi. Yes the Schrader valve cores leak. You replace them and get brass caps that will not only keep out the dirt but can actually hold any pressure that may leak past the cores. The plastic caps are only meant to keep out any dirt and are useless for pressure. The real problem is the hose. It has a leak specification per foot. And that is for NEW hose, not 30 year old sh-t. On a Delorean we have an overabundance of hose, therefore a higher leak rate already. Newer barrier type hose has a much lower leak rate. Are you still running on 30 year old cooling hoses? They only have to hold 12 psi! The high side hose has to handle around 150 psi at around 200 degrees. Do you still think you should be using original hoses? it is like sitting on a loaded gun. BTW, you did replace the plastic header tank, right? Plastic and rubber does not last forever.

[NightFlyer]

Are you still running on 30 year old cooling hoses? They only have to hold 12 psi! The high side hose has to handle around 150 psi at around 200 degrees. Do you still think you should be using original hoses? it is like sitting on a loaded gun. BTW, you did replace the plastic header tank, right? Plastic and rubber does not last forever.

Obviously, David is not very familiar with my car :biggrin:

I'm running original A/C hoses, original belts, original coolant hoses, original fuel hoses, original plastic header bottle, original plastic tanked radiator, original Ducey alternator, original NCTs, original door and louver struts, original bushings and suspension components, original fan fail, original relays, original fuses, etc. My car is 99% exactly as it was delivered to the dealership by the QAC to the dealership back in 1981. Just took it on a 1000 mile round trip to DCS, and while there, took it drag racing at Kil-Kare on Thursday night. Performed flawlessly without incident.

Won third place in the mileage category and a silver level certification in concours judging (would have been gold, and could potentially be stainless with a little more work on presentability, but as to originality, no car there was more original than mine was - judges even commented that my NCTs were the nicest that they had ever seen and that I had one of the nicest interiors that they had ever seen). In fact, I was the only concours entrant that even had NCTs (Ken K's car rode in on its NCTs, but he was local and wasn't entered in concours).

At the awards ceremony on Saturday, I shouted all that out in addition to the fact that I wouldn't hesitate to take my car to California and back the next day in its current condition without hesitation, rose my arms up in the air, asked who else here would be willing to do that, dropped my arms and left the stage.

If this makes me crazy, so be it.

I view it as dispelling bad conventional wisdom with every mile that I put on my car :biggrin:

[Rich_NYS]

I had no A/C on the way to DCS, it sure does get hot in that car.

At DCS, Bill R. got my A/C working for the short-term by pulling vacuum using the car's engine vacuum, then charged it with a few cans.

It was intended to just be a quick fix [to get me home with A/C] but it's still holding. I borrowed a vacuum pump & set of gauges to do a more thorough job.

I'm going to flush, vacuum, and recharge, but I'm definitely not going to be wrenching on anything unless I absolutely have to. I wouldn't doubt there's a minor leak (the R-12 had to go somewhere,) but I'd rather hit it with $5 of refrigerant every year than break & replace stuff.

I'm all for: "charge it & see how it goes."

[tom kish vin. 4357]

Obviously, David is not very familiar with my car :biggrin:

I'm running original A/C hoses, original belts, original coolant hoses, original fuel hoses, original plastic header bottle, original plastic tanked radiator, original Ducey alternator,

At the awards ceremony on Saturday, I shouted, rose my arms up in the air, asked who else here would be willing to do that, dropped my arms and left the stage.

If this makes me crazy, so be it.

I view it as dispelling bad conventional wisdom with every mile that I put on my car :biggrin:

Yep your crazy!!

[alexwolf1216]

I had no A/C on the way to DCS, it sure does get hot in that car.

At DCS, Bill R. got my A/C working for the short-term by pulling vacuum using the car's engine vacuum, then charged it with a few cans.

It was intended to just be a quick fix [to get me home with A/C] but it's still holding. I borrowed a vacuum pump & set of gauges to do a more thorough job.

I'm going to flush, vacuum, and recharge, but I'm definitely not going to be wrenching on anything unless I absolutely have to. I wouldn't doubt there's a minor leak (the R-12 had to go somewhere,) but I'd rather hit it with $5 of refrigerant every year than break & replace stuff.

I'm all for: "charge it & see how it goes."

How much did you put in? I found 12oz cans on eBay for $30~ each. It would take 3 cans to do it properly, and I am certainly not opposed to spending $90 to see If I can make it through the summer.

[David T]

How much did you put in? I found 12oz cans on eBay for $30~ each. It would take 3 cans to do it properly, and I am certainly not opposed to spending $90 to see If I can make it through the summer.

I can understand authenticity and originality. But they and reliability are mutually exclusive. I was also running on NCT's till I realized how dangerous it is (and how hard the ride is!). One burst hose and you can cook the motor and blow the head gaskets. But it is your car and you can do whatever you want to it. Some choose not to do anything because of money. The Ducey WILL go bad. The door lock module WILL lock you in. The fan fail relay WILL fail. None of this is disputable except as to when but it is generally acknowledged it will happen sooner rather than later. I choose to be proactive and replace stuff known to go bad so I am not stuck on the side of the road and will continue to advise others to do the same. Do you still have the original wiper blades? Are you wiling to scratch the windscreen? Where do you draw the line? I say the car is meant to be used and to do that you must do PM and that means replacing parts as they age. Unless you keep the car in a museum or a glass box in a bank. Do you also have the original brake fluid or battery? As for the A/C, yes, you can keep topping off to keep it running. Two problems with that strategy. One, you must also replace the oil as it leaks out and two, the leaks will not only continue, but they will get worse and you will find yourself topping off more often and with larger and larger amounts. That is till you blow out a hose. Now the system won't hold anything.

[Rich_NYS]

How much did you put in? I found 12oz cans on eBay for $30~ each. It would take 3 cans to do it properly, and I am certainly not opposed to spending $90 to see If I can make it through the summer.

Two cans of 134a.

I'm considering using the refrigerant from compressed air cans like I've seen on Youtube. Nightflyer did it and it seems to work really well.

I didn't use R-12 because I wasn't sure how tight the system is.

After I flush, check for leaks...etc, I'll decide if I want to stick with 134a or go to the other stuff.

[Rich_NYS]

I can understand authenticity and originality. But they and reliability are mutually exclusive. I was also running on NCT's till I realized how dangerous it is (and how hard the ride is!). One burst hose and you can cook the motor and blow the head gaskets. But it is your car and you can do whatever you want to it. Some choose not to do anything because of money. The Ducey WILL go bad. The door lock module WILL lock you in. The fan fail relay WILL fail. None of this is disputable except as to when but it is generally acknowledged it will happen sooner rather than later. I choose to be proactive and replace stuff known to go bad so I am not stuck on the side of the road and will continue to advise others to do the same. Do you still have the original wiper blades? Are you wiling to scratch the windscreen? Where do you draw the line? I say the car is meant to be used and to do that you must do PM and that means replacing parts as they age. Unless you keep the car in a museum or a glass box in a bank. Do you also have the original brake fluid or battery?
I agree, but I consider it all under the heading of "risk-tolerance." Everyone has a different level of risk tolerance; I like to check the car over regularly to try & spot any potential surprises that could put leave me roadside, but if I think something isn't a potential issue I leave it alone. That said, I have learned early on from you more experienced guys that there are those things [like you mentioned] that aren't "if" but "when." So...I proactively checked/replaced a few things to hedge against the inevitable(hoses, relays, tires, lock modules, fuse block...etc,) but mostly I just perform maintenance checks and try to be prepared if I have trouble.




As for the A/C, yes, you can keep topping off to keep it running. Two problems with that strategy. One, you must also replace the oil as it leaks out and two, the leaks will not only continue, but they will get worse and you will find yourself topping off more often and with larger and larger amounts. That is till you blow out a hose. Now the system won't hold anything.

True, I've had leaks in my other cars and they usually do get worse. What I normally do is look for the leak when I feel it's getting bad enough to where:

a) I really need to fix it.
b) The leak is significant enough that I'll be able to find it.



Good stuff....!

[NightFlyer]

Yep your crazy!!

Thanks Tom, knew I could count on you :approve:

[NightFlyer]

How much did you put in? I found 12oz cans on eBay for $30~ each. It would take 3 cans to do it properly, and I am certainly not opposed to spending $90 to see If I can make it through the summer.

The thing about the 'see what you get' method, is that you don't want to charge it with expensive refrigerant, unless you don't mind potentially throwing away $100 worth of R-12 should it not work very well in your car because of a large leak or a failed system component. Even if you have a small leak that requires annual and semi-annual recharges, why not go with cheapest refrigerant available that will perform the job adequately? That's why I'm a proponent of R-152a (aka Dust-Off / Ultra-Duster / etc), as you can get a 10oz can for about $2.79 if you shop diligently (even cheaper if you purchase en bulk online), and a full charge only requires 2 cans (20oz). A full charge of R-134a requires 30oz, while a full charge of R-12 requires 35.2oz.

Rich is currently running R-134a with his system's original mineral oil. While this will work just fine, as he's proving, it's not advisable to run such a setup for very long, as mineral oil isn't very miscible with R-134a, and running it long term like this could potentially significantly decrease the life expectancy of the compressor.

Ester oil is miscible with all of the commonly used automotive refrigerants, which is why I highly recommend that at a minimum, you drain the mineral oil from the compressor, backflush the system with a flushing agent that cuts mineral oil (lacquer thinner, mineral spirits, etc), and refill the compressor with ester oil. With ester in the system, future changes in the type of refrigerant you chose to run will be relatively simply and easy.

Let us know if you have any other question!

Best luck on getting your car cool :thumbup:

[NightFlyer]

I can understand authenticity and originality. But they and reliability are mutually exclusive. I was also running on NCT's till I realized how dangerous it is (and how hard the ride is!). One burst hose and you can cook the motor and blow the head gaskets. But it is your car and you can do whatever you want to it. Some choose not to do anything because of money. The Ducey WILL go bad. The door lock module WILL lock you in. The fan fail relay WILL fail. None of this is disputable except as to when but it is generally acknowledged it will happen sooner rather than later. I choose to be proactive and replace stuff known to go bad so I am not stuck on the side of the road and will continue to advise others to do the same. Do you still have the original wiper blades? Are you wiling to scratch the windscreen? Where do you draw the line? I say the car is meant to be used and to do that you must do PM and that means replacing parts as they age. Unless you keep the car in a museum or a glass box in a bank. Do you also have the original brake fluid or battery? As for the A/C, yes, you can keep topping off to keep it running. Two problems with that strategy. One, you must also replace the oil as it leaks out and two, the leaks will not only continue, but they will get worse and you will find yourself topping off more often and with larger and larger amounts. That is till you blow out a hose. Now the system won't hold anything.

It is possible to preserve original components in a fully usable condition - it's a lot of work and requires the use of the right techniques/products, but it is possible, as I like to think that I'm proving it with every mile that I put on my car.

Not to mention that a lot of what I see in the current market place proves the old adage of 'they don't make 'em like they used to' absolutely true. Take the main belt (water pump and alternator) as just one example - the original stock/OEM Renault belt is actually steel cored. All the rubber could practically disintegrate and the damn thing would probably still work somewhat proficiently. Wouldn't try that with a newly manufactured belt though...

I do have the original wiper blades and they're in great condition - don't scratch the windshield at all. I replaced the original brake fluid just last year, however, I'm still running the original clutch fluid (though I do plan on changing it out within the next couple years) - when I first bought the car, it was still orange, but over the last decade has turned grey. Unfortunately, my car didn't come with the original battery, thus I'm currently running a sealed AGM made by East Penn (here in the USA).

I draw the line where I'm relatively certain that something absolutely warrants replacement - otherwise, if it ain't broke, don't fix it. You mention how the Ducey will eventually fail - but so will a brand new alternator. As for the electronics, so long as they're properly maintained (which hardly anyone does), they'll last just as well as anything else made by the hand of man.

Were several of the components used in building the car weak or severely deficient even when brand new - absolutely, and I'm not disputing that. My point is that you can either conform yourself to adapting to the quirks of the car (which is easy to do as human beings are capable of being dynamic), or you can expect the car to conform itself to how you wish to use it (which as an inanimate object, is impossible for the car to do, thus requiring you to spend large sums of money in replacing and upgrading parts). Case in point is the stock braking system - how many times on the forums have we read complaints from people that they're wholly inadequate? When the fact of the matter is that the system was designed when the preferred method of brake usage was pumping the brakes as opposed to standing on the brakes. With the advent of ABS systems being installed on all car over the last two and half decades, several owners today simply stand on the brakes as opposed to pumping them and then wonder why they're not as proficient as they believe they should be, when the reality is that if they used the system as it was originally intended/designed to be used, the system is actually extremely durable and proficient.

IMHO, it takes a lot more dedication, commitment, passion, whatever you want to call it, to conform one's self to the car and preserve the original parts to the best of one's ability than it does to simply buy something new/upgraded and swap it out.

How many part swaps/modifications/upgrades does it take before it's not really a DeLorean anymore, but rather simply a Giugiaro design on a Lotus frame? (that's a rhetorical question, of course)

[DMCMW Dave]

It is possible to preserve original components in a fully usable condition - it's a lot of work and requires the use of the right techniques/products, but it is possible, as I like to think that I'm proving it with every mile that I put on my car.
)

It's important to note that NightFlyer's car was stored for decades more or less in an environmental bubble. Try this with the average DeLorean Barn Find (or worse, Back Yard Find) and you'll see that the wiper blades have dry rotted, the belts have rotted and caused rust on the pulleys, and the NCTs and wipers will look like the ones on this car that just came in. . . . and yes the tires are holding air, but I would not drive it across the parking lot.

So your mileage may vary.

28456

28457

[NightFlyer]

It's important to note that NightFlyer's car was stored for decades more or less in an environmental bubble. Try this with the average DeLorean Barn Find (or worse, Back Yard Find) and you'll see that the wiper blades have dry rotted, the belts have rotted and caused rust on the pulleys, and the NCTs and wipers will look like the ones on this car that just came in. . . . and yes the tires are holding air, but I would not drive it across the parking lot.

So your mileage may vary.

28456

28457

Thanks Dave - you're giving away my best tricks/secrets :biggrin:

Seriously though, proper storage when the vehicle is not in use is key, and as Dave mentioned, that's an extremely rare thing to find - I was admittedly very lucky with my car.

[David T]

Thanks Dave - you're giving away my best tricks/secrets :biggrin:

Seriously though, proper storage when the vehicle is not in use is key, and as Dave mentioned, that's an extremely rare thing to find - I was admittedly very lucky with my car.


I have seen several of these types of preserved cars. They are a time capsule and everything appears to be in like new shape. That is until you start to actually use it. All of the rubber and plastic seems to age very quickly as if trying to "catch up" to it's chronological age. You may be able to use it in it's present condition but as a general recommendation for reliability the best thing you can do is some proactive maintenance. I would start by replacing all of the fluids, filters, tires, and hoses. The fan fail relay is no myth. Same for the door lock module and the Ducey alternator. Since you have an early car you should make sure all of the recalls and bulletins have been done. If you are willing to put up with the breakdowns you can do it as things fail. Take advantage of the years of experience accumulated for the fleet. We know what breaks and how to fix it.

[alexwolf1216]

Are there instructions on how to pull a vacuum, or is there a special tool required to do that?

[NightFlyer]

Are there instructions on how to pull a vacuum, or is there a special tool required to do that?

There are three popular methods for pulling a vacuum on the system:

1) tapping into and using the engine's vacuum (while this isn't ideal, it does work - requires a barbed hose coupler);

2) using a venturi style pump (pump itself is cheap, but it requires a source of continuous pressurized compressed air); and

3) using an electric vacuum pump designed specifically for the job at hand.

This is the electric vacuum pump that I purchased from Harbor Freight:

http://www.harborfreight.com/25-cfm-vacuum-pump-98076.html

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_18961.jpg

With a 20% off coupon, the total cost, including sales tax, was $83. It worked very well.

[David T]

There are three popular methods for pulling a vacuum on the system:

1) tapping into and using the engine's vacuum (while this isn't ideal, it does work - requires a barbed hose connector);

2) using a venturi style pump (pump itself is cheap, but it requires a source of continuous pressurized compressed air); and

3) using an electric vacuum pump designed specifically for the job at hand.

This is the electric vacuum pump that I purchased from Harbor Freight:

http://www.harborfreight.com/25-cfm-vacuum-pump-98076.html

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_18961.jpg

With a 20% off coupon, the total cost, including sales tax, was $83. It worked very well.

With a vacuum pump you should also use an electronic vacuum gauge. The mechanical compound gauge on a manifold gauge set cannot accurately measure a hard vacuum. Other tools I recommend include a valve core extractor so you do not have to work through the tiny opening in the schrader vave, leak detector solution, a tank of Nitrogen and a regulator, a dipstick to measure the oil in the compressor, a charging cylinder or an accurate scale. You are supposed to replace the oil in the vacuum pump every time you use it.

[NightFlyer]

With a vacuum pump you should also use an electronic vacuum gauge. The mechanical compound gauge on a manifold gauge set cannot accurately measure a hard vacuum. Other tools I recommend include a valve core extractor so you do not have to work through the tiny opening in the schrader vave, leak detector solution, a tank of Nitrogen and a regulator, a dipstick to measure the oil in the compressor, a charging cylinder or an accurate scale. You are supposed to replace the oil in the vacuum pump every time you use it.

While all that fancy stuff that David mentioned is nice to have, it's definitely not required to do an adequate job, FYI.

If you already have a manifold gauge set, then the only other essentials that you need are a tapper of some sort (if you're using cans of refrigerant as opposed to a large cylinder/tank), and a way to pull vacuum.

[alexwolf1216]

6) Reinstall the compressor and the hoses to the compressor. Replace the o-rings on the hose connection ports, or if they appear to be visually ok, you might get away with simply reversing the existing ones.

7) Replace the schrader cores in the service ports with new ones (teflon seal cores are highly recommended, but standard nitrile seal cores will work just fine).



I am assuming I can get the orings from any auto parts store, but is this the same with the schrader cores?

[NightFlyer]

I am assuming I can get the orings from any auto parts store, but is this the same with the schrader cores?

O-rings are standard sizes and available at any decent auto parts store (although I just examined and flipped my stock ones).

As to schrader cores - it depends on what kind of seal you want to run on the cores. If you're OK with standard nitrile, then tire valve cores will work just fine and can be found at any decent auto parts store. But if you're wanting to run a more exotic seal on the core, such as teflon, viton, etc, then you're probably not going to find those at your local auto parts places (I struck out when looking), but should be able to find them at a local A/C supply store or even an A/C shop (where I found my teflon seal cores).

[alexwolf1216]

I received my gauges last night, going to pickup the vacuum pump maybe tonight, maybe tomorrow. I really want to just fill and test with R134a, but thats my impatience talking I suppose.

Are these the right ones?
http://www.ebay.com/itm/A-C-Valve-Core-Teflon-Seal-Schrader-Valves-AC-HVAC-Lot-of-4-BRAND-NEW-/281369783779?pt=Motors_Car_Truck_Parts_Accessories&hash=item4182f22de3&vxp=mtr

[NightFlyer]

I received my gauges last night, going to pickup the vacuum pump maybe tonight, maybe tomorrow. I really want to just fill and test with R134a, but thats my impatience talking I suppose.

Are these the right ones?
http://www.ebay.com/itm/A-C-Valve-Core-Teflon-Seal-Schrader-Valves-AC-HVAC-Lot-of-4-BRAND-NEW-/281369783779?pt=Motors_Car_Truck_Parts_Accessories&hash=item4182f22de3&vxp=mtr

Yes - those are the ones. As I purchased a pack from my A/C place, I have plenty of extras. If you PM me with your address, I'll drop a couple into an envelope and mail them to you, if you're wanting to go with a teflon seal.

[David T]

The type of seal on the cores is not all that important. Get some brass caps to put over the schrader valves to seal them tight and it won't matter if the cores leak. Of course if you have those conversion fittings then you should use the best cores you can. They don't make brass caps for the -134 service fittings, just plastic caps to keep dirt out. All of the tools I suggest are not luxuries for a shop. One mark of a professional shop is having the right tools and knowing how to use them. For the DIY'ers they are an expensive luxury and why I recommend you go to a shop where they know what they are doing and have the tools to do it right. For what you can spend getting the necessary tools you can have a shop do the job for less.

[DMCMW Dave]

Don't go crazy tightening the brass caps. I've had a couple in here now where they crushed the opening to the fitting and then the schraders won't come out without some effort (and they tend to break off in the fitting!).


That's not a problem with the plastic ones, and really the plastic ones do seal tight, as good as the o-ring fittings on the pressure switch and condenser fittings, and everywhere else in the system for that matter.

[NightFlyer]

I went finger tight with the stock/OEM brass caps, and then just a nudge extra with the pliers (not even 1/32 of a turn), as that's about how they were upon removing them.

[David T]

Don't go crazy tightening the brass caps. I've had a couple in here now where they crushed the opening to the fitting and then the schraders won't come out without some effort (and they tend to break off in the fitting!).


That's not a problem with the plastic ones, and really the plastic ones do seal tight, as good as the o-ring fittings on the pressure switch and condenser fittings, and everywhere else in the system for that matter.

Damaging things by overtightening them can be said for many parts in a car. TAB's come to mind right away! And then there are the cases where things aren't tightened enough, like ball joint studs! Tightening things is serious business and if you are not experienced you can do a lot of damage. Especially where aluminum is concerned.