My 78 Brat idles and runs great until I brake... then it stalls while driving ad brake to a stop or if I step on the brake while parked. It has been suggested that I have an internal vacuum leak in my brake booster. I have found a used brake booster but think maybe I should get a new one? I have searched every parts place and have come up empty. What now? Any substitute?

Thanks!

Mary

Hi Mary This is Jerry, that could be but there is a valve in the middle of the vacuum line that gose to the brake boster. if that is go bad then the engine will do what your brat is doing. Pull that vale off then you should be able to blow through it one way only. If you can blow through bolth ways then it is shot. Hopes this helps you. Thanks Jerry

Hi Jerry,

I'll check that before changing out the booster... this stalling thing is making me crazy!

 

It drives great, power, everything you'd ever want in a '78

 

When I drive, I go into neutral and brake when I'm going to stop, (stalls). When I take a tight corner, I drop into neutral, brake to slow, (near stall here) then I clutch and grab a gear when I accelerate. If it's a tight turn and the space is confined, the braking may be longer and it will stall. Any braking over 10-15 seconds while driving, causes a stall. Does this make any sense?

Here's what I'd suggest doing to determine whether it's the booster or vacuum line.

 

Take the line off the booster, plug it with something. Start the car, and then wiggle around the vacuum line and see if the engine stalls/bogs down.

 

Unfortunately, I'd probably say that it's the booster. You could probably swap boosters from a similar model and model year near yours.

Mary, that master cylinder I'm sending you has a good vacuum booster on it. Worked great on mine and its only been off the car for about 4 months!