Booster problem?

[jwerty1]

While driving tonight when I would hit the brakes my a/f sensor went completely lean and the truck would start stumbling. I pulled the check valve out of the booster line and it appears to be ok by blowing through it, one way it flows and the other way it does not. Does this indicate a booster leak? Just double checking. Just driving down the road it is fine, as soon as I touch the brakes it goes lean.

[datzenmike]

The one way valve allows air to be sucked from the booster to produce a vacuum. If the engine should stall or quit while driving the one way valve prevents air from traveling back and destroying the vacuum stored there. This way you can still use your brakes at least once to get stopped with assist.

 

Idle engine and shut off. If you unplug the hose from the booster you should hear a hiss as the stored vacuum is released.

[datsunaholic]

That sounds pretty much like a blown booster diaphragm.

[devilsbullet]

its your booster. my z does the same exact thing.  do you lose rpm at idle when you apply the brakes too?

[datzenmike]

Plug the hose and try the idle test.

[jwerty1]

For now I flipped the one way valve and am driving without booster assisted brakes, as that is easier than trying to keep the engine from dying. Thanks for the insight.