Hi yall. My '02 audi a4 b6 brake pedals are rock hard causing vehicle not to stop when I want it to. Anyone have this problem? Recently changed the brake master cylinder and brake pads. Could it be the brake booster..? Please help.
Hard brake pedal
- Thread starter Wzy
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Mines got a split brake booster and is intermittently very stiff so I'd definately give that a check (which reminds me to get mine sorted).
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Has the plenum ever flooded in your ownership, it could have entered the servo then it rusts inside, quite common.
http://repairpal.com/rainwater-may-accumulate-in-plenum-tray-due-to-clogged-drains-026
http://repairpal.com/rainwater-may-accumulate-in-plenum-tray-due-to-clogged-drains-026
If the master cylinder has recently been replaced then I'd check the vacuum pipe going into it is actually connected and not damaged, failing that, start the engine and put your head near the brake pedal and listen to see if you can hear a hissing noise beside the pedal , if it is then the diaphragms split inside the servo.
Sorted. It was the vacuum pipes. Replaced them and brakes now back to normal. Thanks guys.
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For mine you could here the leak right where hose passed through firewall. Top left corner of your image. Temporary fix I put a black piece of electrical tape around where it plugs into firewall. Worked. If you wiggle hose around you can hear the air leak and feel pulsating. A 2nd person was pushing brake and they got better as I wiggle that. So for now I put tape to act as like Teflon tape.
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