2002 Silverado V6. A/C worked fine last summer. Had the freon extracted so I could replace the heater core in November. Only two lines unbolted were the two going into the firewall to the evap.
Bought an Amazon gauge set and rented a pump this morning to vacuum down the system. Let the pump run a little over an hour and it would not go below 26hg. (Should be 28?). After turning the pump off, within half an hour, it was at 20, so obviously a leak.
Strange thing is, I did it a couple of times and noticed that one time, I had the manifold valve closed and had also closed the connector, yet it still dropped. Wondering if the manifold gauge is leaking.
It's probably the system, just baffled because it worked fine before. I put new o-rings on the connection to the evap, but that didn't seem to make a difference.
Is there a way to test the gauges before I have to turn the pump back in?
-Rob
