Brakes on 1994 SL2

Hi all-

My 94 SL2 with 180,000 miles is having a brake problem. The car was
parked with the emergency brake engaged for 3 weeks, and now the pedal
goes to the floor when I try to brake. There was a bit of grab when I
first tried to move the car after it sat, and the emergency brake does
engage when I pull the handle. But while driving, the pedal goes to
the floor and the car slows down very slowly. Thankfully, it was a
very short drive on a couple country roads between work and home. The
fluid level was/is full, and the brakes were serviced ~1000 miles ago.
The car is sitting in the driveway until I can take it apart, hoping
someone will point me in the right direction. TIA to all who reply-

John

 

John --

A couple of things come readily to mind:

1. Recent service on the hydraulic portion of the brakes, and
2. Mechanical emergency brake does not use hydraulic system, and it
appears to work.

Quick thought is an improper brake service, possibly leaving air trapped in
the hydraulic lines. Have the brakes bled down again either by the original
servicing shop, or some shop you trust. Second possibility is a defective
master cylinder (was it changed?), or defective wheel cylinder(s). Are
there any puddles under the car if you exercise the braking system without
moving? Maybe the vacuum boost on the brake system has failed or is loose,
is the engine running smoothly, and does it surge or stutter when you press
the beake pedal? These answers might help point out where the problem lies
........

 

Wow John, how dangerous can you get?

My take is that your master cylinder has failed. If the problem were
simply with the vacuum assist section of your power brakes you'd just
have a very hard time pushing the brake pedal hard enough to slow the
car down very quickly.

Going to the floor sounds as though there's essentially no decent seal
in the master cylinder which allows the 'piston' to move down the bore
without actually forcing fluid down the lines.

You should try to "pump" the brakes - lightly and not very far down.
Eventually you should find a buildup of pressure.

Please dont drive this car anymore until you get it fixed!

-WaV