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1991 Mercedes Benz 420sel Repair Question


Topics covered: Piston, Sensor, Wheel.
Mileage: No information provided.

Asked on July 20, 2010

1991 Mercedes Benz 420sel Brakes

Brakes problem
1991 Mercedes Benz 420sel V8 Four Wheel Drive Automatic 180000 miles

How difficult is it to replace L & R rear calipers, pads and sensors on this car? I have done this on an early model Volvo but on this car I do not know. Right now after installing a new master cylinder, the rear
caliper pistons that hit the disk now do not withdraw completely and consequently it feels llike a slight drag while the car is moving. The sensors apparently are constantly in contact because they are melting. I have tried lubricating the pistons that fail to withdraw once your foot is off the brake but they fail to do so. Any suggestions as to how I can correct this problem? I guess the new master cylinder is exerting too much pressure on the old calipers. Can removing some of the brake fluid help the situation?
Avatar Asked by Theo Zicko

Answer

Replied on July 20, 2010

Hi
Recheck part number for master for your car make sure it is for a four wheel disc brake. If master is for rear drums it has a check valve that holds residual pressure to rears so caliper will be partialy applied.
Let me know
Thanks for donate

Tiny Answered by Docfixit (expert)
18,443 answers provided