Sinking brake pedal
'05 Element EX, 80K miles. NO external brake fluid leakage
If brake pedal is depressed with slightly more force than normally needed to stop car, pedal goes slowly to floor. Shop manual says 3/8" movement in 3 minutes is limit of acceptability with light pedal pressure. I had about 3" movement in aprox 4 seconds. Figured master cylinder was bypassing internally, So bought new Wagner master, bench bled, and installed it. Vacuum bled all wheels in correct order to remove old fluid, topping up master as required during bleeding. Now pedal does same thing, but seems to go down slightly quicker. First application of pedal results in pedal stopping half way down, but a couple further pedal strokes cause the pedal to "pump up" to the top, on application.
If there were air in system, I would expect spongy pedal, but pedal acts exactly like it would if there were a small system leak.
Manual instructions say nothing about bleeding ABS unit--Necessary? It IS a high point in the system.
Any way that ABS unit could be bypassing internally? But then, where would the fluid be going?
Car stops great, it's disconcerting when sitting at a light for the pedal to keep sinking, however.
I detest modern cars!
Last edited by gronk; 03-11-2013 at 12:30 PM.