So I'm trying to change out my a/c compressor today old one puked on me. Ordered a kit off rockauto with compressor, dryer, expansion valve...
pull old compressor off and it looks completely different than the new one but seems like it should mount up. Did somebody stick a random compressor on at some point or what? Any ideas? Stick the new one on and go?



Overall length is different but brackets seem close? TIA

 

It looks like the important parts are all there...Be sure to flush the system thoroughly before reassembly, and add the recommended amount of compressor oil...Let there be cold!......Ben

 

One BIG consideration is what refrigerant to use. If you use R134a you will need a different oil than if you go back to R12. When I replaced my compressor, condenser and lines I went to R134a and I used PAG oil which is compatible with R134a. It doesn't cool anywhere near where I think it should though.

I just ordered 40 oz of R12 off Ebay so I plan to flush out the PAG oil and use POE (ester) oil which is compatible with both R134 and R12. I believe the amount of oil is 8 oz.

I had to dump the oil out of my new compressor when I got it but I didn't flush it with anything. I just took off the inlet and outlet covers and rotated the compressor shaft until no more oil came out. The mineral oil is not compatible with R134. I don't know what oil came in the compressor.

I also plan to replace the filter/dryer which should be replaced anytime the system is opened.

Edwin

 

Well I got everything flushed and put back together with pag oil and vacuumed the system down for about 45 minutes and charged with 2.2 lbs of R134. System is operational and cooling some but seem to have a bad expansion valve out of the box or something. High pressure was running around 400 and the low side about 45. Took some freon back out and both high and low dropped but high side stayed around 325 and low side 35. Ran out of daylight and energy to continue so will work on it another day. Didn't have my thermometer so couldn't check temp drop.

 

That's similar to what I got with R134a The system is designed for R12 and any new parts you get are R12 parts. In order to not pop the high pressure valve on the compressor I had to add much less R134 than would seem to be optimal. My low pressure switch always cycles which is not right.

I'll post back when I get the R12 installed.

Edwin

 

Those pressures are about what I would expect with your system at a road rpm......Ben

 

Your evaporator may be clogged up.I believe that low airflow will cause high pressures.see here:

https://www.dieseltruckresource.com/...18.html...Mark

 

Ive been thinking I should clean my heater/evap box now I'll have to get on it...I have lost some airflow over time I'm sure it's probly got a bunch of junk in it👍

 

Anyone know where to get good complete kits for these trucks? I bought a dorman kit and lost all my R12 though a pin hole on a seal. What happen to the old green gaskets you could get.

 

Do you mean like a complete kit with everything, compressor, expansion valve, oil and o-rings? If just the o-rings you can get them online or at any good ac shop. I put a Chinese made kit in several years ago and it is still freezing me out. I believe it was from car parts.com but I’ll check the thread to be sure...Mark

 

Do you mean like a complete kit with everything, compressor, expansion valve, oil and o-rings? If just the o-rings you can get them online or at any good ac shop. I put a Chinese made kit in several years ago and it is still freezing me out. I believe it was from car parts.com but I’ll check the thread to be sure...Mark

 

Yeah, everything.

I ended up with a few leaks, compressor side and also into the firewall.