I saw NumberDummy post this in another forum and wonder if my A/C is toast.I rebuilt my truck 15 years ago and never charged the A/C after putting everything back together. Is it probably toast since it has had air in it for so long? I was going to get it charged up for use this summer.<!-- / message --><!-- sig -->

 

Just replace the accumulator/drier as the dessicant has long since saturated.

Pull a hard vacuum on it for at least 30 minutes before charging.

 

Depends largely on how much moisture was trapped in the system over time. If it is rusty in the compressor and if it had an expansion valve they may be toast. Reciever dryer as suggested is definitely out.

 

Thanks guys. I'm no A/C guy...Where's the receiver dryer?

 

On a 78 F250? Son I havent worked on one of those Dinos for a LOOOOOOONG Time... just follow the high pressure hose from the AC Condenser... it should lead you there..

 

15 years is a long time for a system to be "open".
Much of the interior is raw aluminum which can corrode over time. A good check for corrosion is to disconnect the condenser and blow through it with compressed air. If you see dust blow out, the system will have corrosion issues and closer inspection will be needed. Do the same with the evaporator. You should be disconnecting all of those parts to replace the seals anyway.

The receiver/drier and expansion valve should be replaced, as the other guys have said. Also, change the oil in the compressor if it is the OEM type York unit.