Hey all, ive got an auto '86 22re, with 3rd Gen dual diaphram brake booster and 1" master cylinder (both just recently installed).

The truck idles fine in park or in gear, but if i pump the brakes repeatedly in park (haven't tried in gear or neutral) the truck sputters. Is this a vacuum issue? Has anybody else experienced this? Didnt notice this issue with the stock booster/mc.

I did a quick search and didnt come up with anything. Please share your thoughts.

Thanks!

 

sure sounds like it's booster-related... i guess that you could try blocking off the vacuum line, verify that it made a difference.

what happens when you hold the pedal down with the engine off, then start the engine with the pedal still held down? afaik, the brake pedal should sink down.

if it's been sitting all night, and you pull the vacuum line at the booster, is it still under vacuum? not leaking?

 

Booster has a vacuum leak