Anyone Know Brakes?

does it make a sucking sound when youre on the brakes?
like a wooooooooosh noise? if so, its probably the booster.

here is an easy way to test your booster for leaks.

start your car and allow the engine to run for aprx. 2 minutes.
shut the car off and pus the brake pedal to the floor.
if the pedal remains steady, the booster is probably fine.
if the pedal slowly rises, the booster has a leak.

if you end up replacing your booster, before your install, inspect the vacuum line going to it. look inside the line and see if there is fluid in it. if there is fluid, this could indicate that your master cylinder is bad as well. your best bet is to buy a power booster kit that includes a new master cylinder.

alot of times, if there is fluid in the hose, this indicates a faulty booster vacuum check valve. a bad bcv valve will actually sometimes allow fumes from the PCV (positive crankcase ventilation valve) to enter into the power break booster after turning your car off. these fumes can destroy the seals inside the booster, and thus a replacement is needed.

to check if your booster check valve is okay, you should be able to pry it off of your brake booster (where the vacuum line goes) and blow through it. if you can blow through in the "booster toward manifold" direction, thats good. however, if you can blow through it in the "manifold toward booster" direction, then the valve is bad. basically it should be one way, with no air going INTO the booster. if the valve is bad, make sure the kit you get has a new valve as well as the booster and master cylinder.