Leak in new system

jdfxc49 on Thu July 15, 2010 9:10 AM

Year: 1993
Make: Chevrolet
Model: c1500
Engine Size: 5.7
Refrigerant Type: 134a
Ambient Temp: 103
Pressure Low: 0
Pressure High: 0
Country of Origin: United States

I've just replaced all components of my a/c system. I have a leak and I can not seem to find it at this time.
Any and all ideas on how to find this leak will be appreciated. I can draw a vacuum of around 28 to 29 using my gauge
set but the system will leak down in a few minutes.

Dave in Texas on Thu July 15, 2010 9:49 AM

I had a similar problem after replacing accumulator. All connections had new o-rings and I always use Nylog on all mechanical threaded connections, but had a very slow leak. Finally found the source in High side service port valve. New valve innards and leak all gone! If your truck is a conversion from R12 to R134a, the old schrader valve core could be the culprit.

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At 2, I went home with a 10. At 10 I woke up with a 2 !!

jdfxc49 on Thu July 15, 2010 1:56 PM

I have all new schrader valves with nylon gasket and no leaks detected!
Thanks for your reply
I believe the leak is in the hose to compressor connection?

mk378 on Thu July 15, 2010 2:17 PM

There are different types of sealing washers for that connection; make sure you have the right one. The R-12 compressors and hose sets are different from later ones with factory R-134a ("stepped" vs. "flat" across the block).

Cussboy on Thu July 15, 2010 2:23 PM

A few months ago I re-did brand-new compressor and brand-new accumulator in my Suburban. The accumulator came with 2 O-rings, but one on the system previous was substantially thicker than either of the two supplied. Rather than use one of those, I went to CarQuest and matched up the thicker O-ring, cost 25 cents. What did your new O-rings look like compared to old?

jdfxc49 on Thu July 15, 2010 4:18 PM