Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

1976 Buick retrofit questions

cmeseadoin on Fri August 15, 2008 8:40 AM User is offline

Year: 1976
Make: Buick
Model: Electra 225 Limited
Engine Size: 7.5Liter
Refrigerant Type: R134A

Hey guys,

I have a couple of questions. I have been messing around with the A/C on my 1976 Buick Electra 225 limited for a while now off and on trying to get it working correctly. I did a 134A conversion on it and here is what I did several years ago. I replaced the compressor with a new one, I flushed the entire system and installed a bran new EEVIR assy from ackits.com with a new desiccant bag in it and all new orings at all the connections to it. The R12 service port schrader type fitting had the schrader removed and I installed a new r134a retrofit service port connection overtop of those with red and blue caps for high and low side. On the HIGH side, I installed a high pressure switch as part of the service port connection and wired that in to where it could shut off the clutch engagement if needed. There is no low pressure switch currently installed. I had to re-tune the POA valve inside of the EEVIR a little to get the a/c working well, but I had it to where it was doing pretty well....BUT my problem is I keep springing leaks at the front compressor shaft seal on the A6 and losing my refrigerant charge and spinning oil off the pulley all around the engine bay. I have now had front shaft seals on two compressors go on me and I am getting ready to go at it again. Here is what I have observed....

I noticed that before, the compressor clutch never disengaged and the compressor was running and spinning all the time that I had the a/c on. The high pressure switch never disengaged the clutch (don't know what pressure it works at, was from ACKITS too and just screws onto the old r12 port). Seeing as there is no low side cut out, the clutch and compressor is spinning all the time. I am wondering if I could be over-pressurizing the system and causing my shaft seal to blow as I understand from reading that the A6 was prone to doing that. I am not an a/c expert by any means, but I understand how they work and have done a fair amount of various work with good success. I don't have any other leaks in the system that I have ever been able to find, I'm losing it all from the front shaft seal.

To someone that knows the components of this system; could someone tell me what components SHOULD be installed in a 1976 Buick with a 455 V8 running an A6 and a VIR assy with regards to an r134a conversion? Should a LOW pressure switch that can be adjusted to maintain a certain low side pressure in concert with vent temps go into the system so that the compressor should cycle or should I expect that at the proper R134a charge in this system, that my compressor is ok to run all the time that the system is on? Does anyone know what the high side pressure is that the high pressure switch trips out at? I would love to figure all this out and stop my shaft seals from springing catastrophic leaks. Thanks to anyone with an informed opinion!!!

mk378 on Fri August 15, 2008 1:02 PM User is offline

VIR systems will run the compressor all the time normally. The valve regulates the cooling and evaporator temperature via pressure. They do not need a low pressure switch.

The high pressure switch is only to prevent blowing out hoses, etc. under abnormal conditions of excessive pressure, for example if the condenser fan quits. It should never open in normal operation. Typically they are set for 450 psi or so.

The A6 especially and all GM compressors are prone to shaft seal leaks. Are you using lip seals or mechanical seals? The lip seals are reportedly better, as long as the shaft is in good condition.

cmeseadoin on Fri August 15, 2008 10:50 PM User is offline

Hey MK378:

Thanks for the information, what you said makes sense to me and is how I was running the system. I have done some research on the A6 and seem to find that they are def. prone to leaking. Is there some other compressor that I can install in this car other than the A6 do you think? I am, quite frankly, sick of dealing with a leaking compressor because outside of that, I'd have a nice functional a/c system in this car. I am not into it enough to know what type of seals I have....how would I know? I just ordered another reman'd A6 from this site today to try one final time doing it all correctly from A-Z. If this fails, I will probably quit dicking with it and say screw it. The car is a toy and I'd like the A/C to work, but I am not sinking 100's into it. I don't have the tools to pull the seals out and redo them either. I was wondering about trying to do that. I am very mechanically inclined, but I am not sure how much effort I want to exert as I can well afford to keep buying compressors, but I want to find one that is not a leaky pile of junk and be done with it.

cmeseadoin on Fri August 15, 2008 10:53 PM User is offline

For me, it's that fine line between being able to afford compressors and it is easier than buying tools and pulling the other one down.....and also not wanting to waste the money if they keep failing. I don't want to put 425.00 into a new one, just not important enough to me, esp. when a reman'd one is 133.00. The first mistake I prolly made was I used a reman'd, I think Ready Aire or something,buick225 from the local store...been told they are a POS. I figure I'll try one from this site....seem to have good products and name.

JJM on Sat August 16, 2008 12:16 AM User is offline

I somewhat remember you and this project... and thought you bought everything from Tim. If you bought a chain store compressor, no wonder the thing is leaking all over - they're paint 'n ship jobs.

Get the compressor from Tim and you should be fine. You might want to check if they come with the better double lip seal, and if not, perhaps his shop can "update" the compressor for a nominal fee.

Joe

When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com

NickD on Sat August 16, 2008 7:54 AM User is offline

Kind of remember these cars having a large evaporator box on the right side with the compressor right in front of it, was easy to work on compared with some of this new stuff. Isn't there a capillary tube evaporator thermo switch mounted near that evaporator box that is suppose to switch off the compressor when the evaporator temperature hits 33*F? And switch it back on at about 38*F, has a screw adjustment. Of course if you don't hit 33*F and really can't if you have lost refrigerant, the compressor would never turn off. Just rings a bell, but that was a long time ago.

cmeseadoin on Tue August 19, 2008 12:14 PM User is offline

Quote
Originally posted by: JJM
I somewhat remember you and this project... and thought you bought everything from Tim. If you bought a chain store compressor, no wonder the thing is leaking all over - they're paint 'n ship jobs.



Get the compressor from Tim and you should be fine. You might want to check if they come with the better double lip seal, and if not, perhaps his shop can "update" the compressor for a nominal fee.



Joe



When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com

No, I got all the other parts from Tim minus the compressor. This time, I ordered the compressor from Tim. We'll see what happens.

cmeseadoin on Tue August 19, 2008 12:20 PM User is offline

Quote
Originally posted by: NickD
Kind of remember these cars having a large evaporator box on the right side with the compressor right in front of it, was easy to work on compared with some of this new stuff. Isn't there a capillary tube evaporator thermo switch mounted near that evaporator box that is suppose to switch off the compressor when the evaporator temperature hits 33*F? And switch it back on at about 38*F, has a screw adjustment. Of course if you don't hit 33*F and really can't if you have lost refrigerant, the compressor would never turn off. Just rings a bell, but that was a long time ago.


You are correct as far as placement of the evap box and compressor location....but there is no switch in this car that monitors the evap temp that I know of. There is what looks like a resistor in the evap box, but I think that is the resistor for the blower fan itself. There are no other switches or wiring anywhere that looks like it has a thing to do with the A/C system of the car. The system is basically just the condensor in the front end, the eevir assy, the compressor and the lines as well as the evap itself. It is very easy to get to and easy to work on like you said. That is why I was curious if there was some type of clutch cycling switch in the equation other than the HIGH pres. switch I put in when I did the R134a conversion. According to mk378 in an earlier posting, he explained that these VIR driven systems do not typically have cycling switches. From what he says and how he explained it, it makes sence to me. I will be installing the new compressor when it gets here, we'll see what happens this time as far as the leak. The A/C was nice and cold before, just blew the shaft seal.

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.