A/C problems. Help me understand my guages - Page 2 - PeachParts Mercedes-Benz Forum

jcyuhn · #16 08-24-2007, 02:19 PM

Quote:

Originally Posted by tangofox007

You might be right; it could be "pegged" on either end of the spectrum.

Don't think so. He has 110PSI low side with the compressor running. There's no way the guage is going to read lower than that figure when the system is shut down. I think we can have some confidence that "pegged" implies the high end here.

vstech · #17 08-24-2007, 04:51 PM

Quote:

Originally Posted by 777funk

The 87 300d is finally getting the A/C RandR it deserves.
Anyways, I have some gauges and I'm charging the Freon level. I had the compressor off and replaced it and the dryer. I also ordered a new expansion valve but when I saw where it was (Behind the brake booster) it scared me. I pulled a 29"HG vac and it held just fine. Anyways, I started charging it. Here are my numbers:

Car not running:
Low Side-Pegged
High Side-160psi or so

Car Running at idle:
Low Side-110psi
High Side-Pegged until the compressor shuts off. I jumpered the low pressure/level switch on the dryer a moment and the compressor stays on. With out it jumpered it cuts on and off ever 10 seconds or so.

Lastly when the car turns off Low and High should equalize. Am I right??

Any ideas what's the matter here? My guess is maybe the expansion valve.

hey, are you still alive?
did your a/c system explode? let us know how much freon you put in that thing. with those pressures, you have to be pumping liquid in the compressor, so it's gonna be shot if you aren't careful. reclaim all the freon in your system, and weigh it, I be you have like 8 lbs in there.