This is driving me nuts! When i press the brake pedal my truck bogs down then revs up. I cant seem to find any vaccuum leaks, i checked for leaks with propane. would this be a syptom of a bad check valve? any ideas?
Only vacuum @ brake system would be @ the power booster. I'd check all the hoses & the unit for problems!
Your idle is probably set to high... The surging is the injectors cutting out (ECU thinks truck is slowing to a stop when the brakes are applied). Lower the idle down a bit and it should stay steady.
Your break vacume booster is bad this has happen to me a few times on my 87 runner and an other one I have currently so replace your booster and will solve the problem deffinatly