Today while I was driving my brake pedal went to the floor. At the time I was turning into a parking lot so I cautiously parked the car and then checked my brake fluid level. All was in order so I figured that my master cylinder must be going bad. I went about my business and returned to the car to see if I could cautiously drive it home and to my surprise the brakes worked just fine and still do.

Does anyone have a possible explanation for the pedal going to the floor? It happened on two separate insidents within the same day.

I did not look for a warning light at the time nor did I notice one. (1987 300E Diamond Blue))

__________________
Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

The pedal was acting up again today. At times it is low near the floor and I can pump it up to normal. Is there anything in the Mercedes 300E brake system that could cause this other than the master cylinder?

If its the master cylinder, can I get a kit from Parts Shop?

__________________
Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

What shape are your pads in? If they are worn out, the caliper pistons will require more fluid to make up for the increased travel. You may have gotten some air into the system. Three likely causes, air in the system. leaking brake line somewhere, master cylinder is heading south. If it's the MC replace it. Not worth the trouble and expense of rebuilding, and.. with the brakes, don't mess around with a major safety issue. Be safe, fix it right. The life you save may be your own or someone you love. Cost about $105 here at Parts Shop (cheap insurance)..

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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

Thanks Jeff. I think that if it were air in the system then the brake pedal would be consistantly low except when they are pumped... Constant low pedal would also happen with worn pads. The situation I find is that the pedal functions well at times and at other times it seems to slip while braking. (like if a wheel cylinder is leaking badly) However I am not losing fluid.

If it is the Master cylinder... why do you think it is too difficult to rebuild? Is there something about MB cylinders that make them difficult to rebuild? The cost you mention above.. is that for new brakes or a master cylinder?



[Edited by ejsharp on 06-30-2001 at 11:50 PM]

__________________
Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

That's for a new Master. As a rule, I never try to rebuild a master cylinder. They're not that expensive to replace and, the peace of mind is well worth the cost..

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.