RPM increases when pumping the brake

flyboy · Post by **flyboy** » Wed Apr 30, 2008 10:20 am

This just seems strange to me but when I pump the brake, my engine RPM goes from about 1000 up to 1500 +. If I just hold the brake down, the RPM stay steady at around 1000. The RMPs only increase when I pump the brake repeatedly and the faster I pump, the faster the engine speed goes.

I discovered this after doing a little brake work and needed to get the caliper pistons back in place after pushing them in with a clamp.

So Cal Mark · Post by **So Cal Mark** » Wed Apr 30, 2008 10:35 am

you're moving a large amount of air when you repeatedly pump the brake pedal

baltobernie · Post by **baltobernie** » Wed Apr 30, 2008 10:36 am

Pinch the vacuum line to the booster and see if problem goes away

... or sell this performance-enhancement to Mike for those Michigan Lefts.

So Cal Mark · Post by **So Cal Mark** » Wed Apr 30, 2008 1:15 pm

if holding the pedal down steady doesn't increase rpm, then the booster is okay

flyboy · Post by **flyboy** » Wed Apr 30, 2008 4:04 pm

So Cal Mark wrote:you're moving a large amount of air when you repeatedly pump the brake pedal

What air is moving by pumping the brake pedal? And does this mean that when everyone else pumps their brake pedal their RPMs increase?

mdrburchette · Post by **mdrburchette** » Wed Apr 30, 2008 6:24 pm

Mine does. That's how I kept it running at stoplights when I had a Holley carb on it.

RPM increases when pumping the brake

RPM increases when pumping the brake

Re: RPM increases when pumping the brake

Re: RPM increases when pumping the brake

Re: RPM increases when pumping the brake

Re: RPM increases when pumping the brake

Re: RPM increases when pumping the brake