Alternative A/C Test Methods

[Finkaire]

When you pull the gauges from a fully charged system and the schrader leaks you can install a good cap with a good seal with a little ester or A/C mineral oil and with all probability stop the leak. I was surprised as well when told of the cap being the primary seal.

 

[bucket]

When you pull the gauges from a fully charged system and the schrader leaks you can install a good cap with a good seal with a little ester or A/C mineral oil and with all probability stop the leak. I was surprised as well when told of the cap being the primary seal.

Right, but just because someone can get lucky and make the cap seal against a leaking Schrader does not make it a primary seal. Just like a valve cap on a wheel's valve stem, the Schrader is the primary seal. The cap is only there to keep out debris. This isn't just my opinion, but fact.

 

[Ricko1966]

Now to make thos more difficult,when I was taught,the instructor told us always replace the caps as a backup defence against a seeping Schrader valve. Wording was something like every now and then one will leak down over the course of months and the cap would have prevented it. That would infer to me the Schrader is the primary the cap is a backup,whether intentional or not. And I have a stack of GM training certificates as thick as a phone book LOL. @Bextreme04 gets it lol.

 

[Finkaire]

A/C specialist 45yrs. primary/secondary, a leak is a leak.
Had more problems with ball valves, always carried spares, shraders too.
A nice tightly fastened service cap with a good seal might save a backyard wrench.

 

[Finkaire]

Also remember to test the detector, check the checker.
Most leaks don’t get better, it should eventually show up visually as an oily spot. If you can’t find it on the engine side of the firewall it might be the evaporator. Tear down to inspect, maybe a bore scope, might have access through the resistor on the evaporator housing, check the drain tube, also a good place to put the sniffer. You can also build up pressure in the system for testing by placing a piece of cardboard in front of the radiator. Good luck, I’ve known dealers that just keep throwing parts at it as mentioned.