63 A/C Dryer

[Harry S.]

I have an A/C dryer from my 63 that was cross threaded. As a result the rebuilder would not rebuild/restore it.

I got a tap and carefully fixed the threads. Everything goes in straight and tight. I put a new set of O-rings in and did a leak test. It held 20 inches of vacuum for 18 hours then I took it apart. I was getting ready to send it back out to the rebuilder and they said it needs to hold 250 to 300 pounds of pressure. I have a problem with these numbers. They said a leak test is not a good test it must be a pressure test.

Well before any readonable A/C shop will dump freon into a C2 they want to perform a leak test to ensure the freon stays in the system

Thoughts, comments, Help?

I think I'm done after the leak test I performed, correct? or should the number be higher?

[Edward J.]

Re: 63 A/C Dryer

Harry, The high side system pressure is generally operating at 200 to 300 PSI, The low side pressure is 25-35 PSI this is all based on the out side temp, higher outside temp. will relate to higher system pressures. the dryer is mounted on the high side pressure line. The system is drawn into a vacuum to should hold a 30 in. vacuum before it is recharged it should hold a vacuum for about 20-30 minutes. this is not a fool proof test, as a very small leak the high side may not always show. I am taking that the rebuilder does not have a pressure tester that will go that high, If not how will he rebuild the dryer for you and correctly pressure test the part when complete. I Believe the canister is cut open and install new material internally And then welded closed. I have never seen this done, so its the only way possible I can think of. I have replaced the material in some late model cars but not a lot of dryers can be serviced , As the corvette is one of the cars that is just a replacement type. I know that keeping the original part is your quest, If you feel the fitting will work fine than ask him to rebuild the part, there are not a lot of a/c guys that do this sort of stuff, who are you using.

[Harry S.]

Re: 63 A/C Dryer

Ed thanks, I'll crank it up to 30 and see what happens.