EClancy

Whenever my foot is on the brake pedal, i can hear a hissing noise coming from somewhere. I know i have a brake problem, as i have to pump the brake in order for it to not go to the floor. Not very safe i know . What does that hiss mean? I did a search, but am still kinda confused. I suck at doing brake repairs on anything but air brakes. i thought i had a leaky master cylinder, so i replaced it two weeks ago, its no better and appears to be leaking where the master cyl bolts onto the booster or whatever that is.

ANyway, on sat morning i was driving to my parents house on I90 when i blew the outer brake hose on the front passenger side. I kept driving about 18 miles with no brakes to get home. had to special order the hose from autozone, as they did not stock it, got it monday morning, went to replace it, and broke the fitting and metal brake line that attaches to the hose. So, there my truck sits in my parent's driveway, waiting till i can get back down there and make a new front metal line, and install the new hose. Don't ya hate when something could be a 5 minute job and it turns into a weeklong hassle. ANyways, so once i get the truck mobile again, it time to look intio whatevr makes my brakes hiss.

Always something.....always something

apache

Bad diaphram in the brake booster?

Falcon1

Yes had to replace mine and BTW brakes worked better after I replaced it also.

wannadiesel

Another BT,DT on the brake booster. On a gasser you would have had to replace it by now because the engine wouldn't idle.