Hi, On a 94 caravan what controls the pressure of the refrigerent? The wifes van keeps killing the compressor. It works for about 2 weeks then stops cooling and the compressor is all shot inside. It is set up for 134a. I took one of the compressors apart and it looked to me like it didn't get enough lube. The pistons and bores were all scored up and the wobble plate was all worn out also. Could something be wrong that the pressure is to high and killing the compressor or is it a oil problem? When I put on a good compressor it sounds like it is working really hard before it burns it self up. I would love to take it in and have someone who really knows this stuff fix it but it would probably cost more than the van is worth. The wife uses the van for work, she is a RN and does homehealth with it so she spends alot of time in it on the laptop and it gets terrible hot in there some days. I don't have a high side guage so I have no idea what it is when it was cooling if I remember right the low side is about 60-65lb area. I may have talked about this problem last year, if I did sorry to bring it up again. I just left it over the winter but its getting about that time again. I know where I can get another good used compressor cheap but I am sure it will just burn it up again if I don't find the problem. Is it possible that metal particals from the first compressor have something plugged up in the system? I put on a new dryer with the last compressor also. If I take the lines off the dryer is there anything I could maybe pump through the system to clean it out good before recharging it again? Is it OK to use envirosafe in place of 134a? Envirosafe says its ok to mix with 134a and there oil is compatable with the 134 stuff but I wonder if its really true with all the problems I have with it. I have it in my old Suburban and has been working good for 5 years now but that had r12 in it I assume, it was empty from a loose connection on a pipe when I got it. Tom
Major compressor failure can plug the condenser. That system needs to at least be flushed. You could try denatured alcohol and compressed air. Dissasemble the system (remove expansion valve, drier and compressor). Pore some in the hoses and blow it out with compressed air. You should change the drier again, might even need an expansion valve. You need to add oil to the system when replacing parts. New, used or rebuilt compressors may have oil in them. Some times just a little, other times a full charge. If you flush it you will need to replace the oil flushed from the evaporator, hose and condenser. That system probably holds 5-8oz of oil. If it has dual air you should do the same for it, and add oil. Low side should not be above 40psi. High side should be about 220psi. max. This varies depending on ambient temp, but is close for ball park. It has a low pressure switch, and should have a high pressure cut off switch. I would only use R134, but I am in the business and play by the rules. I only use new compressors, used and rebuilt usually cause failures or leaks. I would guess you had it over charged and low on oil. Get a service manual, or go to the library. This link may help. http://ackits.com/ HTH John
Thanks for the help/advice. I will get a valve and dryer for it and try to flush it all out. I am thinking I am going to replace the stuff and flush it the best I can then put things together and take it somewhere to have it checked for leaks and recharged. Tom
