Join Date: Feb 2004
Location: Vancouver, BC, Canada
Brake pedal goes to floor, engine at idle
Ok, first try this, with your engine running at idle, press hard on the pedal, can you make it go to the floor?
I've just about torn off all my hair trying to figure out exactly what's going on, and for the last year or so I just can't come up with an explaination.
Apparently, many cars do this. A list I've gathered include: Mustang, Corolla, Lancer, Sonata, Jetta. Here're 3 cars that I know for sure that DON'T do this: 1995 BMW 530i, 2005 Mazda 6, 1988 Mazda RX7.
Here are many possible explainations:
1) Air in the system. I've bled the brakes twice in the last year, each time using an entire quart to make sure it's done properly, so no.
2) Bad master cylinder seal. This would also cause the symptom of a "sinking pedal", which mine doesn't do. I have a "spring effect" symptom. i.e. feels like a large spring is under my pedal.
3) master cylinder flex due to thin firewall. I spent 7 hours fabricating a master cylinder brace, and now the MC doesn't even budge when I'm heavy on the brakes. But the pedal will still go to the floor.
4) leaky hoses. No, my fluid level is perfect.
My biggest defence against many speculations is the fact that with the engine off, my pedal is as stiff as the pedal on an F1 car! I can apply about 200 lbs of force, and the pedal barely moves 1/4". This means I have NO AIR in the system, and the MC seal is GOOD.
So, anybody has any idea of what might be causing this on our cars?
The only other thing I can think of is caliper and hose flex, but they shouldn't flex so much that the pedal goes to the floor.
most importance of all though, verify this on your car!!! This is not something you'd likely to notice in normal driving, unless you're on a racetrack
2003 Police Package
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