I have a 1987 Buick Regal Limited V6 231 na-(2barrel carb). When I apply the brake the rpm drop and when you release the brake the rpm goes back. The power booster has been changed and so has the check valve and the brake booster hose. I have checked for any vacuum leaks and not one to be found. I was thinking of trying a vacuum pump and see if that helps.
If anyone has an idea of what could be the cause, I'm all ears because I'm stumped.
Thanks, Rob
If anyone has an idea of what could be the cause, I'm all ears because I'm stumped.
Thanks, Rob