sparky605

Hello. I am new to this post. I have a 97 silverado. About a week ago, I noticed a kind of "SLLLLLL" sound coming from the brake pedal when I depressed it. Kind of hard to explain the sound. I've noticed the sound even when the pickup is stopped and in park as long as I have the pedal depressed. The last couple days, when I press the pedal, it makes the same sound and the pedal goes almost to the floor. It is like I am losing pressure. I have kept an eye on the fluid level and don't notice much loss, if any. I don't notice any leaks under the truck. Any help is appreciated. Thanks.

ukrkoz

so, you got the wooshing noise? coming from sort of underneath the dasboard? and pedal slowly goes down into the floor?
well, sounds like booster diaphragm failure to me. air leaking out, hance the noise.
emergency fix is to pump up brake pedal, as it builds up pressure. but has to be fixed asap, your life - and others - at stake.

sparky605

Thanks for getting back to me. I am in the process of changing the booster. On the brake pedal where it connects to the rod, there is a plastic piece. Any idea on how to take that off? Thanks.

ukrkoz

does not say. there's a brake light switch on the pedal that needs to be removed. **yne* says
pry off the clip retaining the brake switch and the booster pushrod to the pin on the brake pedal
otherwise, there are no plastic pieces mentioned, it all unbolts from under the hood. you need to remove some of the dashboard cover and air duct. master does not need to be disconnected from the lines, just unbolted from booster.
clip for the switch appears to be on the left hand side of the pedal, right behind the light switch.

i donno if you want to mess with this, booster can be disassembled and diaphragm replaced, instead of buying the whole piece.

http://www.autozone.com/addVehicleId...00c1528008f726

sparky605

Well, I got it changed. I decided to change the whole booster. After taking the old one out, there was a plastic piece by the brake rod that was broken. This may or may not have added to the problem. But, I switched it out and it works fine. There is a small metal retainer that keeps the rod on the pedal. It must also keep the stop lamp switch on the pushrod. Anyway, once I got the retainer off, the plastic stoplamp switch came right out. There are 4 nuts right under the dashboard that hold the booster to the frame that needed to be taken off. Not fun getting to those. So, thanks for suggesting changing the booster and your other advice. I appreciate it.

ukrkoz

you most welcome. hope everything works out fine for you, it's SAFETY.