Calipers, Rotors, Pads, Lines & more- OEM and Aftermarket
By rusty_eg3
#6907720 Hey everyone. I think the brake booster might be failing. The pedal doesn't get harder during braking or anything, I've also tested it according to the service manual and it seems to be ok BUT sometimes, after the car sits overnight, the pedal is harder like somebody keeps pressing it with the engine off. Lately, this problem appears more often. Should I consider buying another brake booster? The hoses seem to be fine.
User avatar
By teal_dx
#6907739 I forget how many miles you have on your car, but I know it's a lot... I haven't seen one go bad in person, but with that much use, I bet it's possible. First though, I'd examine the check valve in the hose from the booster to the intake manifold.
By rusty_eg3
#6907743 I have 122 k miles.

Checked the check valve :D and it's ok. Brake booster definitely needs replacing, I've come to the point where I shut off the engine with the pedal pressed and as soon as the engine is off, the pedal feels much stiffer and if you can hear a hissing. Is it dangerous to drive like that? Just bled the brakes due to a master cylinder upgrade and I don't want to do it again. Is it possible to change the booster without unbolting the brake lines from the MC? I highly doubt it though. Thanks!
User avatar
By teal_dx
#6907752 There might be enough flex in the metal brake lines to slide the MC off of the booster. The part I dread is on the other side of the firewall, working up under the dash.