Buick air condition check valve

[Guest oakland]

I am looking for the little check valve that sets on top of the intake manifole that goes to the air condition controls. I loose vacuum when I accelerate the car and checked all the vacuum hoses, which seem OK. The manual says that my problem is probably do to a bad check valve. I looked everywhere and even went to the local parts store, but no luck. Would appreciate any info.

[Jim Cannon]

What year car?

Instead of trying to replace the factory check valve, you could just add a second inline vacuum check valve between the engine and the first control piece.

Every little element of the A/C vacuum system needs to be tight or you will lose vacuum. If yo have a '63, thee is no vacuum storage reservoir for the A/C system in the stock setup. Buick added one in '64 and later, to overcome the very thing you are experiencing.

If you have a little storage can, make sure it is tight. If you have a '63, consider adding a little storage can from a later year car. (That's what I did).