300 SL Mushey Brake Pedal

[moohampshire]

Started to get a spongy brake pedal a few weeks ago when the red brake light came on in the dash. Just thought when depressed emer brake switch stuck. After a few weeks the light went out. While it was on if I hit a bump it would go our briefly but come back on. Now if i pump pedal it gets harder and the brake light comes back on. Any idea of what the problem is. The car will stop but the pedal is abount 3 inches from floor. When pump pedal it stops better.

[rowdie]

Low fluid. Leaking brake cylinder.
If level is ok and no fluid leaks. Master cylinder.

[coleyjf]

Could it also be worn disc pad(s)? - -Can't remember when they started fitting the sensors but I've got them in my 88 300SL

Cheers

Jim

[mrelbe]

Mushy pedal = air in the system. Check for leaks and master cylinder level. If low, fill up and bleed all brake cylinders.

[moohampshire]

Checked for leaks today and have none. In about a week the level in resevoir went from max to about a 1/4 inch down. Where can the fluid be going. If I pump up pedal it is not mushey. What is going on. Will check pads next week but that will not explain fluid levle goinf down.

Help

[RadioTek]

If you have air in your system, it will sometimes cause these symptoms. As the temperature changes, it will expand or contract. Air is a lot more compressible than brake fluid. If you can have the system flushed with a pressure bleeder, it will eliminate that possibility. Sometimes, when the master cylinder has air in it, a pressure bleeder is the only way to get it completely bled.

Good luck.

[Roncallo]

Originally Posted by moohampshire

Checked for leaks today and have none. In about a week the level in resevoir went from max to about a 1/4 inch down. Where can the fluid be going. If I pump up pedal it is not mushey. What is going on. Will check pads next week but that will not explain fluid levle goinf down.

Help

Replace your master. The fluid is leaking into the power booster. Also try to get as much fluid as possible out of the power booster.

Also if anyone has a lead on a Tachometer with clock for a 300SL, Im looking for one.