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View Full Version : What is this part? Check valve?



scott 4991
01-22-2007, 08:05 PM
Not sure what this is. I think it's some kind check valve, PVC? Should it be cleaned? How do I know if it's bad / working properly? I see a vacuum lead here, closed off. Any one know what the vacuum should read at this location so I can check mine against a know good value?

Thanks

sc

Blitzkrieg Bob
01-22-2007, 08:10 PM
line for the brakes.

the brake booster uses vacuum to power the power grakes

Rus
01-22-2007, 09:30 PM
That is in fact a check valve. It allows for the vacuum from the intake manifold to operate the brake booster. It's purpose is to prevent vacuum fluctuation in the manifold due to you applying the brakes. The extra nipple is a known vacuum leak source and thus shouldn't be disturbed. HTH

Bill R.
01-22-2007, 10:54 PM
allow vacum to be stored in the booster so you have some assist for a stop or two if the engine stalls while driving, If the check valve is working correctly you can push the brake pedal down a couple of times with the engine off and you can feel the boost go away as you use up the stored vacum. The pedal gets harder and higher.



That is in fact a check valve. It allows for the vacuum from the intake manifold to operate the brake booster. It's purpose is to prevent vacuum fluctuation in the manifold due to you applying the brakes. The extra nipple is a known vacuum leak source and thus shouldn't be disturbed. HTH

scott 4991
01-22-2007, 11:27 PM
Thanks guys.

sc

2fast
01-23-2007, 12:42 AM
Thanks I always wondered what that thing was:)

Dash01
01-23-2007, 01:18 AM
Not sure what this is. I think it's some kind check valve, PVC? Should it be cleaned? How do I know if it's bad / working properly? I see a vacuum lead here, closed off. Any one know what the vacuum should read at this location so I can check mine against a know good value?

Thanks

sc

PCV, methinks. Those factory clamps suck, and allow vacuum leaks. Better to replace and/or wrap some electrical tape over this and other potential leaks.

Rus
01-23-2007, 02:31 AM
allow vacum to be stored in the booster so you have some assist for a stop or two if the engine stalls while driving, If the check valve is working correctly you can push the brake pedal down a couple of times with the engine off and you can feel the boost go away as you use up the stored vacum. The pedal gets harder and higher.

I stand corrected :)