Thread: Low Power brake booster vacum

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lt1s10,
I sent a few pictures for you to see, I checked the oneway valve and it checked OK. I will check the power brake unit to see if it is holding pressure.

Denny,
It is rubber hose, I did not know that they had PVC hose?? is it PVC Vacum hose ?

deny's right about the hose, if you have 17" of vac, at idle, and you still have a hard peddle, then you have the wrong hose, bad one way valve or a bad booster. take the hose off the one way valve on the motor side and see if it holds vac. in the booster, or see if you can blow through it both ways.

Thanks guys, I will get the correct hose, recheck the one way valve and check the power booster to see if it holds vacum. I will keep you up to date. Thanks again.

Can't tell for sure from your picture, but it looks like the vacuum fitting you're using on the carb might be to a port that is above the throttle butterfly. This won't give you any vacuum at idle. The hose looks rather small, too. Have you put a reducer in the line to match the size of the hose to the fitting on the carb? The vacuum line needs to get full manifold vacuum, which is usually taken from a fitting on the intake manifold.

Hot Rod Roy has a point, that port is for PCV and may be a bit undersized for power brakes. Find a source of manifold vacuum. There should be plugs in the manifold somewhere.