[croni]

My car feels like the master cylinder is loosing pressure. 1) The pedal has @ an inch of initial travel before the brake assist/big brakes stick like glue. 2) If I pump/hold the pedal it will slowly compress toward the floor.
3) It behaves the same regardless of how recent I've bled the calipers.

Is this normal or is it time for some brake work?
Any others with similar symptoms?

Thanks,
Chris

 

[scorchie]

This is common among nearly every C43 I have driven (quite a few), including mine.

Howe...

This is common among nearly every C43 I have driven (quite a few), including mine.

However, it can be changed with OEM parts, or it can be changed by upgrading your brakes. With OEM parts, try this:

1) replace master cylinder, flush system, check operation. The low pedal engagement is a classic symptom of master cylinder internal failure. There are no rebuild kits for these, but the cost is only around $200-250.

2) if the above has no change, replace the front calipers with calipers from CLK55. I believe the change in these calipers was to switch seals from square to round, to reduce the pullback of the pistons after releasing the pedal. While you're at it, replace the brake lines with stainless steel, and flush the system. You should end up with a nice, firm, quick engaging pedal. Unfortunately, these new calipers are quite expensive...

-s-