Does Defrost work better with A/C Compressor?

[wasted wages]

High side , I agree.....

low side pressure should not exceed what the static system pressure would be with the truck off on a hot day outside......probably not above 150....

with a R22 trace and 150 lbs nitrogen using my halide torch,,, I find 99 % of my leaks....using my H10 pro.....I find the tiny ones..

 

[smalltruckbigcid]

No fair you're using R22. We get to use R134. And I don't get to make shop policy. Thats the way they want it done.

 

[British Slave]

You guys do realize the system equalizes when the compressor is not running. There is no high side/low side unless the system is in operation.
Another note, the shaft seal is designed to hold pressure and vacuum. It has to hold vacuum to prevent the introduction of foreign material and moisture in the event of system pressure loss.

 

[wasted wages]

No fair you're using R22. We get to use R134. And I don't get to make shop policy. Thats the way they want it done.

Buy a 30 pounder of R22 and use it just for leak testing.....your going to pull a vacuum on it anyway.....makes your life a lot easier.......

You guys do realize the system equalizes when the compressor is not running.

Yup....already mentioned that.....but the STATIC pressure of an equalized system is NEVER going to be as high as the 350 psi he is referring to for leak testing.....especially on the low side.

Another note, the shaft seal is designed to hold pressure and vacuum. It has to hold vacuum to prevent the introduction of foreign material and moisture in the event of system pressure loss.

Correct........but they ALL leak.....the final seal is a film of oil...which by design...leaks...it may be on a molecular level....but it does leak and brings refrigerant with it...or in the case of a vacuum, pulls atmospheric pressure into the system...

why do you think 99.9% of the compressors built today are hermetic and semi hermetic ??? to eliminate the shaft seal... I have worked on 3-400 ton open belt driven recip compressors....we would take a beer can and cut the top off and wire it under the shaft seal to catch the oil drips from the seal...it's a given....all shaft seals leak...its just how much...