rknight

I have a 98 Chevy Express 1500. A/C worked great until a few days ago. Compressor wasn't kicking on at all. Jumpered the low pressure switch and it runs fine. Low charge, right? So I get the guage and put it on the low side valve on the accumulator and observer two things. First, 0 psi ... not good. 2nd, a hissing sound like the guage can't get a good seal. Checked the guage on another truck and it is fine. If I put my head as close as I can (not that close on these vans) when the compressor is running, no guage, no cap on the valve, I *think* can hear some hissing but not sure. Unfortunately I don't have a stethoscope to hear better.

Questions:

1. Is this a common place for leaks?
2. Can the shrader valve be replaced or do you have to do the whole accumulator?
3. How the heck do you get the thing out of there in these vans ... tight quarters.

MDTAHOE

Answers:
1. Yes it is a common place, but it should not leak with the gauge on it.
2. Yes the core inside can be changed.
3. The core is the similar to one on a tire and a tire tool could be used.

However the proper way to repair it would to have a shop completely empty the system, change the part, then the system need to be put under vac for at least 15 min. If it is not Vacuumed then you will never get it to work as good as it could.

rknight

Well it defintily has a leak. Put a can of r134a in ... only took it up to about 25 psi. With the A/C running for about 15 minutes, no pressure loss. Shut off the van, come back 15 minutes later, down to about 20 psi, now down to about 15 psi.

I picked up a 12 oz can of r134 with dye in it. Going to put that in and hopefully will be able to tell where the leak is. If I don't see dye anywhere else, I'll assume it's the shraeder valve.

In terms of having a shop empty it, what's the point if it loses all its pressure eventually anyway? Based on where it was when I started today, I expect 0 psi come morning. Can't I just fix the valve and/or replace the accumulator, then take it to the shop to have them evac and charge?

One other thing I just thought of ... how about if I leave the guage on it overnight ... see if it leaks. That would isolate it to the valve as well right?