Brakes Change Rpm’s

75cj 304. When I take my foot off the brakes, the rpm’s go up slightly for a moment then return to normal. Is this a vacuum thing ? Applying the brakes does nothing to rpm

 

Power brakes?

 

Yes

 

Yes, sounds like a vacuum leak. When you add more air (larger leak), engine speed goes up. The power brake vacuum system is simple - a hose from the intake manifold, a check valve on the booster, and the booster can itself. The check valve is plastic and widely available - something to try. I would replace the hose from the manifold too. I'd think when you release the pedal, the booster volume goes up and the speed should go down. I'm not that sure what is happening; I would look for vacuum leaks and the booster plumbing.

 

Yep.. Tim is on it..

 

New check valve…90% fixed. Going to replace all hoses. And, on a side note, ran some sea foam through the gas tank, and WOW. Like a new motor