Back brake issues ,1984 300cd. - PeachParts Mercedes-Benz Forum

chasinthesun · #1 07-01-2012, 04:08 PM

The drive into work yesterday proved eventful with my rear brakes ceasing,Ive had this issue before and it was remedied with a replacement of the rear calipers and pads.Well thats what I thought anyway, got new calipers and new pads on her and still have the same issue after driving 2 miles down the road ,the pads seem to be not releasing after driving a few miles.Any thoughts? a collapsed brake hose ,wheel bearings going out or something weirder.The emergency brake has shoes ,do you think this could be it ? Both back brake calipers are getting hot ,enough for you to smell the pad,hense the 2 mile test .If both sides are doing it at the same time what could be the cause ?

ah-kay · #2 07-01-2012, 04:31 PM

Master brake cylinder. It happened to me on 2 cars, 300D and 190D. Both rear brakes bind after a short drive. Changed out calipers 2 times and to no avail.

chasinthesun · #3 07-01-2012, 06:00 PM

Thanks ,Ill go in for the brake master cylinder in the morning ,I didnt do the rear brake hoses yet so I might as well get it all fresh and new for the system.In all it will cost just north of $200. for rebuilt parts ,then throw in the $80 tow bill ,Im still ahead though doing my own labor.

ah-kay · #4 07-01-2012, 06:26 PM

Quote:

Originally Posted by chasinthesun

Thanks ,Ill go in for the brake master cylinder in the morning ,I didnt do the rear brake hoses yet so I might as well get it all fresh and new for the system.In all it will cost just north of $200. for rebuilt parts ,then throw in the $80 tow bill ,Im still ahead though doing my own labor.

Just a suggestion to save towing charge. When it binds, loosen the rear brake hard line at the master cylinder to release a little fluid and you are good to go until it happens again.

This will also confirm the MC is faulty.

Good luck.

chasinthesun · #5 07-03-2012, 04:06 PM

Its confirmed ,the brake master cylinder was no good,that makes 3 confirmed different issues Ive had go wrong with shticking back brakes on differnet MBs ,#1 bad calipers due to old age ,rust gets to the sleeves,#2 rear rubber lines callapsing ,#3 bad master cylinder.The resorvior had some gunk at the bottom ,used some brake cleaner to swoosh it around then dump and repeat ,making sure to add then dump some brake fluid to wash any remainder out.Then onto installing it onto the new mbc for bench bleeding ,the part came with the small lines and adapters to bleed ,it all worked out were I didnt have to bleed the system after install ,nice brakes now .If I had to do this job over again it would have done the works ,new calipers ,rubber lines ,pads ,and the mbc ,I was fishing one out at a time which took way longer .