A/C Accumulator (dryer) Removal

[bfloyd]

Started working on replacing my A/C Accumulator last night by trying to remove the old one. The big bolt / fitting on the bottom hose was easy, but how do you get tools way up on the top / rear of the accumulator to remove the connection to the evaporator? I don't want to mess up the evaporator, I just can't see how to get to it.
http://i.imgur.com/wWLJv0tl.jpg http://i.imgur.com/LaEoDOZl.jpg

[FABombjoy]

You want to remove the fuel pump access cover. Before you do that, be sure you've presoaked the connection with penetrating oil.

I just did this about a week ago and I was able to get an adjustable crescent wrench on the accumulator body fitting and wedged it against the wheel well. Then on the topside I used another long wrench on the removable fitting and tapped it until it broke free. With the wheel well wrench (say that 3 time fast) secure you'll be able to get a little more aggressive and not damage the evaporator.

[bfloyd]

Thank you... Never even occurred to me to go through the trunk via the fuel pump access panel. Makes sense now. Weekend fun awaits.

[kings1527]

It is a tough angle to get in there but I got a bit creative with a couple wrenches and it worked great.

4470244703

[Bitsyncmaster]

I dropped the accumulator first and then used an impact with a crows foot.

[dn010]

The last one I did I cut the accumulator into sections and used wrenches on the remaining fitting with all freed up space. It took a while but it was done to avoid damaging the evaporator which ended up damaged anyway.

I later found this, if you need a visual:
http://www.deloreanreborn.com/index.php?itemid=126

[jmettee]

Out of all the jobs I've done on my car (& it's been a lot!), this was the job that cause me to cuss & throw things more than anything else. Aside from getting tools at an angle to be effective, I had a heck of a time breaking the original accumulator loose.

All the new stuff going in was lubed with anti-seize.....for the next time!

[Bitsyncmaster]

I dropped the accumulator first and then used an impact with a crows foot.

That suggestion was for the fuel accumulator. I must have been sleeping.

The AC accumulator I had no problems but some fittings used a wrench on top (through the access panel) and the other wrench underneath. The fittings do not need to be very tight since the seals are done with O-rings.

[Christian Dietrich]

http://uploads.tapatalk-cdn.com/20160722/4ecb28afd17fe538b25088005fcabf35.jpg

Lol started doing mine last night. Pretty simple job with the right tool!

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[DMC5180]

I just did this job last weekend using a combination of multiple crowfoot adapters.

Pita

Dennis

[Christian Dietrich]

Anyone have an issue reinstalling the orifice tube? I think someone was in the before and bent the tube that holds the orifice. Came out crooked. This hole job has been simple and everything came apart and had it all out and apart in 35 minutes. Now im getting my butt handed to me with the orifice/expansion valve.

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[Bitsyncmaster]

Anyone have an issue reinstalling the orifice tube? I think someone was in the before and bent the tube that holds the orifice. Came out crooked. This hole job has been simple and everything came apart and had it all out and apart in 35 minutes. Now im getting my butt handed to me with the orifice/expansion valve.

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Coat the new orifice with refrigerant oil and just push it in. It really does not have to be pressed in all the way. Just as long as the o-ring is in the evaporator tube. OK for some to stick into the mating pipe.

[Christian Dietrich]

You know, i never thought it going into the pipe being ok. You think after all the years doing cars, that never crossed my mind! Lol. I guess in my mind, it has to go all the way in!

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[DMC5180]

You know, i never thought it going into the pipe being ok. You think after all the years doing cars, that never crossed my mind! Lol. I guess in my mind, it has to go all the way in!

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If you think about it, the high pressure differential will likely push the orifice in till it fully seats anyway.


Dennis

[gullwinger]

The accumulator is the easy part. USE PB FLUID the night before and use crows feet or really good open ended wrenches I think they are 19mm and 23mm??. The condenser is the worst job I have ever done on the car. But with time and motivation you should be good.

[David T]

The accumulator is the easy part. USE PB FLUID the night before and use crows feet or really good open ended wrenches I think they are 19mm and 23mm??. The condenser is the worst job I have ever done on the car. But with time and motivation you should be good.

Just be really careful not to turn, twist or otherwise put any strain on the large aluminum pipe. If it gets damaged you will be removing the dash and heater box to replace the evap core. SO, if you think replacing the dryer/accumulator is a big job.............

[dn010]

Just be really careful not to turn, twist or otherwise put any strain on the large aluminum pipe. If it gets damaged you will be removing the dash and heater box to replace the evap core. SO, if you think replacing the dryer/accumulator is a big job.............

This is why any future accumulator removal I have to do, if I even have the slightest bit of trouble unfastening the connections, I will be cutting the whole accumulator down in pieces so I can access everything easily. I'm on my third evaporator...

[Christian Dietrich]

If you think about it, the high pressure differential will likely push the orifice in till it fully seats anyway.


Dennis
Yeah and i thought about that also. Other than not thinking clearly on that part the job was fairly simple and it did not take long at all to remove everything and reinstall it and I didn't even soak anything!

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[Bitsyncmaster]

The AC lines on my car were not on very tight. With some other projects, I usually buy some cheap wrenches and grind or bend them to get a good grip on both hex heads.

[Christian Dietrich]

The AC lines on my car were not on very tight. With some other projects, I usually buy some cheap wrenches and grind or bend them to get a good grip on both hex heads.
I usually keep wrenches in my box that are like that. Luckly, i just reached in there and cracked them loose so I guess it's possible mind we're never really that tight as well?

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[Christian Dietrich]

Got my A/C properly charged today to 2 1/2 pounds of R134. Still dont feel all that cold. What im thinking is the cause is because my dumbass not thinking and repainted the condenser with black spray paint when i was restoring the condenser and not knowing there is special paint for condensers to make them look fresh and new. So im going to assume the paint isn't helping to release the heat as the air is going across the fins. Ugh, been a mechanic for 20 years and learned something new. Seriouslyn never heard about the condenser paint when i was at GM, never had that issue nor did i ever restore a car with such great detail!

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[Bitsyncmaster]

Got my A/C properly charged today to 2 1/2 pounds of R134. Still dont feel all that cold. What im thinking is the cause is because my dumbass not thinking and repainted the condenser with black spray paint when i was restoring the condenser and not knowing there is special paint for condensers to make them look fresh and new. So im going to assume the paint isn't helping to release the heat as the air is going across the fins. Ugh, been a mechanic for 20 years and learned something new. Seriouslyn never heard about the condenser paint when i was at GM, never had that issue nor did i ever restore a car with such great detail!

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I would not think your black paint would affect the condenser that much. I did a short drive (4 mile to store) yesterday and my vent temp in the center only got down to 54 deg. The best test of your AC is to record what you get with the AC set to normal and blower on #3 or #4 and note the outside temp. If your using MAX AC then your vent temp depends on how long you drive and if the sun is shinning. If using MAX and your cabin temp is 70 deg. then your vent temp gets a lot colder.

[Christian Dietrich]

I know here its hot and very humid. When i left i didnt have my temp gauge with me but i know my other cars feel much cooler. I was told that the black paint on a condenser doesn't help the heat to dissipate as fast so your AC will be a little warmer than normal. Which is a valid point considering the condenser releases the heat from the fans to cooler the charge. I would like to get the door windows tinted because that's a lot of sunlight that comes in also and later on maybe I'll go out and get a reading with my temperature gauge. I was told a while back that I shouldn't have painted the condenser with black aerosol spray can paint and that there is a special paint specifically for condensers.

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[content22207_2]

In Post #13 you were having trouble seating the orifice tube. You need to put at least a low pressure gauge on to ensure you're getting the low side drop (~30 PSI, though my experience has been R134 works better at 20-25 PSI). If you don't have any gauges all parts houses sell ridiculous expensive freon cans with gauges attached (don't know how accurate they are).

Color of the paint on the condensor wouldn't be an issue, but potentially clogging the fins with paint would. Condensor is made of aluminum so getting any paint to stick will be a challenge. I stripped remaining factory paint off mine (it was flaking off anyway) and just run it bare:

45378

If you have a set of manifold gauges, what is your high side reading? If your low pressure switch is set near 30 PSI, even on a 100 degree day the high side shouldn't get much above 300. If the high side is too high then it is indeed possible the freon can't recondense.

Bill Robertson
#5939

[Christian Dietrich]

In Post #13 you were having trouble seating the orifice tube. You need to put at least a low pressure gauge on to ensure you're getting the low side drop (~30 PSI, though my experience has been R134 works better at 20-25 PSI). If you don't have any gauges all parts houses sell ridiculous expensive freon cans with gauges attached (don't know how accurate they are).

Color of the paint on the condensor wouldn't be an issue, but potentially clogging the fins with paint would. Condensor is made of aluminum so getting any paint to stick will be a challenge. I stripped remaining factory paint off mine (it was flaking off anyway) and just run it bare:

45378

If you have a set of manifold gauges, what is your high side reading? If your low pressure switch is set near 30 PSI, even on a 100 degree day the high side shouldn't get much above 300. If the high side is too high then it is indeed possible the freon can't recondense.

Bill Robertson
#5939
I don't know what the reading was since my car was in the back shop getting done and I used to have a set of AC gauges when I sold them because I never really use them since I got out of the car business a couple years ago. I know the color of the paint doesn't matter but like you said because there is paint on their it retains the heat on the aluminum and prevented from dissipating as the air is coming in to the condenser and I'm sure that's what the issue is because the car will get really nice and cool but not cold like you would feel in a new car and I know my car used to blow colder than this before I did all the AC work. I did use a media Blaster to get all the paint off and then I use black spray paint just because it originally was black. It wasn't until later that I found out that there is a specific paint that you can put on there made specifically for condensers and I know my pressures are fine because I looked at the gauges when I temporarily filled it up with a can and everything was fine with the gauges that it comes with but I definitely would like to get another set of AC gauges and feel like an idiot for selling my old ones.

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[Bitsyncmaster]

Our D is terrible with the sun heating that dash board along with the rest of the cabin. Get one of those little dial temp gauge to stick in your vent which are sold in auto parts stores.

On a real hot day with your circulation fan on speed 3 or 4 you probably would not pull the low side down enough to even shut off the compressor so setting the low pressure switch lower will do nothing but maybe ice your system up on cool days.

With the car not moving and engine RPM about 3000 you would expect to read 40 to 50 PSI on low side and 300 PSI on high side on a 100 deg. day.

Your high side pressure would run about 250 PSI with a larger condenser like in your other cars (designed for R134a) with the same testing.

You may have charged it with to much R134a which would show a higher PSI on the high side.

[content22207_2]

Compressor will still cycle at highway speeds. Doesn't do it very often, but I've heard the radiator fan relay clicking on & off back there. I typically drive at night so outside temps are usually 80-90. Without the sun beating down I've got to turn the blower motor to speed 1 (I use Max A/C so the heater core blend door can't moderate vent temps).

Bill Robertson
#5939

[DMC5180]

Got my A/C properly charged today to 2 1/2 pounds of R134. Still dont feel all that cold. What im thinking is the cause is because my dumbass not thinking and repainted the condenser with black spray paint when i was restoring the condenser and not knowing there is special paint for condensers to make them look fresh and new. So im going to assume the paint isn't helping to release the heat as the air is going across the fins. Ugh, been a mechanic for 20 years and learned something new. Seriouslyn never heard about the condenser paint when i was at GM, never had that issue nor did i ever restore a car with such great detail!

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The factory recommended charge of R-12 is 2.2 lbs per the factory service bulletin.

R134a equivalent is 10% less or 1.98 lbs

(2.0 lbs) rounded up.

2.5 lbs of 134a is TOO MUCH and can cause poor cooling performance.




Dennis

[Christian Dietrich]

The factory recommended charge of R-12 is 2.2 lbs per the factory service bulletin.

R134a equivalent is 10% less or 1.98 lbs

(2.0 lbs) rounded up.

2.5 lbs of 134a is TOO MUCH and can cause poor cooling performance.




Dennis
That was told to me by Don Steger!

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[DMC5180]

That was told to me by Don Steger!

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Are you sure he was talking about 134a or R12?






Dennis

[Christian Dietrich]

Yep cause i sent him a message on fb.

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[Christian Dietrich]

Yep cause i sent him a message on fb.

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http://uploads.tapatalk-cdn.com/20160813/99542cc64eeb08163267857f830f0571.jpg

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[Christian Dietrich]

I can try and release a little and see if it helps? Im still thinking me painting the condenser did it.

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[DMC5180]

I can try and release a little and see if it helps? Im still thinking me painting the condenser did it.

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He is technically correct, but you took it to the MAX thinking More is better. Which is not the case here.

The original factory spec was 2.75lbs Freon (R12). A/C Service bulletin ST 29-11/81 reduced that amount to 2.2 lbs starting at VIN 4080.

134a charge is 90% of R12 charge

R12 2.75 lbs - 10% = 2.475 lbs ( 2.5lbs ) rounded

R12 2.2 lbs - 10% = 1.98 lbs (2.0 lbs) rounded.

The problem with Venting some out is that you never really know where your at unless you start at zero fill.

I charge my own A/C too, but if I am unsure where it is and want to know exactly. I take it to a shop. They will recover want is the system and then put it right back in the amount required or you tell them. typically about a 15-30 minute job with the service machine. they will credit or charge you for the difference in refrigerant used. For me its worth the piece of mind knowing the fill amount is accurate.

[Bitsyncmaster]

If you can get a high pressure gauge on the high side. You could just "recover" the excess R134a until your high pressure drops to about 300 PSI at 3000 RPM.

Another option is put the temp gauge into the center vent and "recover" until your temps drop and then start to rise. To much charge will drive that vent temp higher. Do that testing with both doors open, AC on Normal and fan on #4.

[Christian Dietrich]

He is technically correct, but you took it to the MAX thinking More is better. Which is not the case here.

The original factory spec was 2.75lbs Freon (R12). A/C Service bulletin ST 29-11/81 reduced that amount to 2.2 lbs starting at VIN 4080.

134a charge is 90% of R12 charge

R12 2.75 lbs - 10% = 2.475 lbs ( 2.5lbs ) rounded

R12 2.2 lbs - 10% = 1.98 lbs (2.0 lbs) rounded.

The problem with Venting some out is that you never really know where your at unless you start at zero fill.

I charge my own A/C too, but if I am unsure where it is and want to know exactly. I take it to a shop. They will recover want is the system and then put it right back in the amount required or you tell them. typically about a 15-30 minute job with the service machine. they will credit or charge you for the difference in refrigerant used. For me its worth the piece of mind knowing the fill amount is accurate.
Thanks DMC5180! I should have read my bulletins first. I guess i wasnt think and said the max and should have said the lesser anount. Its been years since i did ac work on a car

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[DMC5180]

Good luck [emoji106]


Dennis

[DMC5180]

If you can get a high pressure gauge on the high side. You could just "recover" the excess R134a until your high pressure drops to about 300 PSI at 3000 RPM.

Another option is put the temp gauge into the center vent and "recover" until your temps drop and then start to rise. To much charge will drive that vent temp higher. Do that testing with both doors open, AC on Normal and fan on #4.

Dave,

Are you being facetious with your "recover"? [emoji6]

I'm not quite sure how you "recover" without a service machine. I have a vacuum pump but don't know how you would add a tank/can for recovery.


Dennis

[Bitsyncmaster]

Dave,

Are you being facetious with your "recover"? [emoji6]

I'm not quite sure how you "recover" without a service machine. I have a vacuum pump but don't know how you would add a tank/can for recovery.


Dennis

Yes. I have the EPA certification to repair AC systems so I don't want to say vent.

[Christian Dietrich]

Good luck [emoji106]


Dennis
Thank you Mr. Dennis! I'm sure it could be just slightly over charged or the fact that I used regular high temperature spray paint instead of using the proper paint for condensers. Either way I screwed up and one or two directions but it's not that big of a deal to fix and I appreciate a nod in the right direction.

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[WHO1DMC]

Need a cross reference for a accumulator for a later vin?

Thanks Dave B.

[WHO1DMC]

OK scratch that I need help on high and low pressure sensors.

Thanks Dave B.

[bfloyd]

Jumping in here late. So starting with an EMPTY system (new hoses, accumulator, condenser, etc.) the correct amount of R134a would be 2.0 lbs?

I literally just dropped my car off at the shop to have the system evacuated and charged. My mechanic asked what the system capacity is and how much refrigerant it will take. Told him I'd ask here and get back with him. Since I'm running the new smaller diameter DPI hoses, does that make a difference in capacities?

[DMC5180]

OK scratch that I need help on high and low pressure sensors.

Thanks Dave B.

The LP switch should have a GM number on. I had to replace mine recently with a crossover Part from 4 seasons. I took the switch with me and looked it up OLD School in Catalog. GM used a half dozen P/N's for the same part over the years. Luckly the parts store had one at there nearby warehouse. I don't have the number now but could get for tomorrow.

I replaced the HP switch with NOS from DMCH.


Dennis

[Delorean Industries]

With a stock capacity condenser the system requires 36oz (three cans) with our lines

[DMC5180]

With a stock capacity condenser the system requires 36oz (three cans) with our lines

R12 or 134a?


Dennis

[Delorean Industries]

134

[bfloyd]

With a stock capacity condenser the system requires 36oz (three cans) with our lines

I've got the DPI lines, compressor and accumulator, however I've got Hervey's new condenser which is a little smaller than the stock condenser. I'd say it covers approximately 3/4's of the face of the radiator.

So still 36oz?

[dn010]

I don't know about the high pressure switch but for the lower pressure switch & accumulator you can shop your favorite parts house for these, tell them they're for a 1984-86 Corvette and you'll get what you need. I believe I used the VOV from the same vehicle.

EDIT:
From Autozone:
Low switch: MT0207
Accumulator: 4430N, it will come with O-rings.


Need a cross reference for a accumulator for a later vin?

Thanks Dave B.

[Delorean Industries]

Back it down just a little and see where pressure is at

[DMC5180]

134

Interesting, that seems to conflict with the factory SB the stated 2.2 for R12 which translates to 2.0 for 134a. Not that the difference is that significant.


Dennis

[Delorean Industries]

Our hoses are actually longer over all compared to stock to allow for routing around the trans/exhaust.

[DMC5180]

I did notice that. I also have the reduced size replacement evaporator from DMCH.


Dennis

[dn010]

Interesting, that seems to conflict with the factory SB the stated 2.2 for R12 which translates to 2.0 for 134a. Not that the difference is that significant.


Dennis

This is why Josh loves the forums!!

Sorry, I just had to.

[WHO1DMC]

Thanks for the help. Went to auto zone but this is not only place for the accumulator and low pressure switch you can find it under 86 corvette and dmcmw for high switch. Can't find the high pressure switch any where else without paying through the nose even though it is spend y.


Thanks Dave B.

p.s. I like working on my D but eeeeesh.

[Morpheus]

I did notice that. I also have the reduced size replacement evaporator from DMCH.


Dennis

Do you have a pic of this?

[Bitsyncmaster]

Our hoses are actually longer over all compared to stock to allow for routing around the trans/exhaust.

It's nice to have the hoses a little long. You can always cut off a little hose if necessary. We ended up cutting about 4 to 6 inches off your low side hose.

[DMC5180]

Do you have a pic of this?

The Replacement Evaporator the DMCH supplied circa 2010 is slightly shorter in length. They send along a big roll of tar tape that you use to build up the ends to fill in the void left from the original ( inside the Evaporator housing)
I think I have photos of it before the housing was assembled someplace. I'll see if I can find then this weekend.




Dennis

[DMCMW Dave]

The Replacement Evaporator the DMCH supplied circa 2010 is slightly shorter in length.

Dennis

BTW the one supplied now is an exact match for the original Evaporator. For some reason they still ship the Evap kit with about a mile of the black tar stuff but you don't need very much at all, just to wrap the outlet lines.

[DMC5180]

I wasn't sure if it had been updated. That's why I included 2010. Glad to here it's a more direct fit. I hope to never need to replace it again.


Dennis

[dn010]

Good to know. The last evaporator I bought from a different vendor was much smaller than original, I wasn't happy about it but installed it anyway ...

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[JAZ_DMC]

You want to remove the fuel pump access cover. Before you do that, be sure you've presoaked the connection with penetrating oil.

I just did this about a week ago and I was able to get an adjustable crescent wrench on the accumulator body fitting and wedged it against the wheel well. Then on the topside I used another long wrench on the removable fitting and tapped it until it broke free. With the wheel well wrench (say that 3 time fast) secure you'll be able to get a little more aggressive and not damage the evaporator.

This is very helpful. Thank you!