Idle goes up

[hotrod69camaro]

On my 69 camaro with power brakes, if im sitting at a stop light with the car idling in neutral or the clutch in. If I put my foot on the brakes the engine idle goes up about 200 rpm and stays as long as I hold the brakes. I this normal or do I have a vacuum leak?......... Thanks guys

[Sieg]

Remove the vac line from the manifold to booster and cap the manifold port and test it........in your driveway. That test should help confirm the source......I think.

[hotrod69camaro]

I know the motor is going to have to give some vacuum to assist the booster. It just seem to me that by the rpm's staying up while the brake pedal is pushed, that the vacuum must be going somewhere. I didnt have any clamps at either the booster side or the manifold side. I didnt before this latest modification to the car either. Thought Id try a ty-wrap at each end and get a new vacuum hose just for good measure.

[Sieg]

It could be the hose fittings or the booster itself leaking. Zip ties may not seal tight enough, wire pinch clamps or traditional hose clamps may be better.

[Hydratech®]

Open and shut case of an internally failed vacuum booster diaphragm creating a very large vacuum leak when the brake is depressed. (rip / tear in the diaphragm).

[hotrod69camaro]

Brand new booster too with 400 miles on it.