1982 240d rear brake problems, time to upgrade?
 

My 1982 240d has been occasionally acting like the right rear brake was dragging for a while now, and it suddenly got worse last week. Last night I tore apart the rear brakes, had to beat both calipers off the rotors they were seized up so bad. Both calipers are shot, the rotors are surprisingly ok. I got to it before the pads ate through to the backing plates. On both the inside pad showed significant wear, the outside pad not so much. The calipers are ATE brand, I'm fairly sure.

The car is sitting up on stands right now and my question is should I be looking to upgrade brakes at this time? My plan was to go through the fronts soon anyway, and I've been hearing about W126 rotors and calipers as a direct swap. Not sure if that's just front or both front and back though.

Also, any opinions on pads? I found Wagner makes a ceramic, which I'm inclined to purchase because I appreciate the low dusting and long life of ceramics. Pretty much don't like semi-metalics due to the dusting issues, and organics have pretty short lives and fading issues so that's where I'm at although I could be convinced to change my mind if presented with a good argument otherwise.

There isn`t anything on the rear to up grade to. all MB bodies use the same rear brakes more or less. except for the wagons, those are pricy.

you could up grade the rotors to the drilled ones with the lines cut into the face I guess.

I would just replace the rears with the stock calipers, rotors, and I guess you could use the ceramic pads for less brake dust. as long as you are replacing parts, would be a good idea to replace the brake hoses as well.

the front brakes can be up graded to the W126. the first generation 81 - 85, the 14 inch wheels can be used. second generation W126 86 - 91, then you need to go to a larger wheel, 15 inch or larger.

If you have the hub caps, I don`t know if the steel wheels or the light alloy wheels will clear the W126 calipers.

Charlie

Cool, thanks Charlie. I didn't realize the rear brakes were the same between them. Any reason to stick with ATE vs Bendix or Girling? I'll definitely replace the fronts with early W126 rotors and calipers if it's a direct swap. I've got a warped rotor up there today, drives me nuts but I figured if I swapped on another solid disk I'd just warp it up as well. Both rear brake lines are new as of one year ago. I'll give them a good inspection though. My wheels are 14-inch bundts.

If you change wheel sizes it may affect your speedometer...might take some work to re coordinate that...

wheel size only affects odometer readouts if you use the same profile size, if you reduce profile size, to match original outside diameter, no speedometer adjustment is needed!!:cool:

Here's a great little app to help you out with that:
Tire size calculator

I've found my 240d is off already anyway. Indicated 70mph is more like 66. It's ok though, my Scout will read 55mph and you're actually doing 62, so it balances out somehow. That's what I'll tell the judge.

You might very well have a flaking brake hose. This will happen sometimes where a flake of rubber acts as a one way brake valve. The hoses are cheap and it would be a good idea to replace them every 15 years or so. Do it at a time when you're opening up the hydraulics for some other reason.

Got the brakes swapped out today. Two new calipers, cardone remans. I've read some folks are unhappy with their quality, but at the very least both have a Merc logo filed down on them, so I'd guess they started life as genuine MB calipers. Strangely the bleeder valves between them are different. One is a 8mm and the other 9mm. Don't know what's up with that. I had a hell of a time bleeding them too. Mityvac couldn't pull them down for some reason. I had to get the wife to pump the pedal down to get the air out. Brakes work real nice now, better than I've ever seen in fact. Very happy with the Wagner ceramics as well. Can't wait to go through the fronts now.

I think I'll keep the originals and rebuild them myself, for fun and learning. Anyone here ever do that themself?

did you change the rubber hoses?

oh, and vacuum to bleed brakes is never a good idea, nearly always just sucks air out the bleed screws...

No, I replaced the rubber lines less than a year ago. I pulled them with the old calipers and inspected them, no problems found.

I just bought the Mityvac since I couldn't find my cheapo bleeder. Guess it was a bit unnecessary if you can't vacuum down brakes.. Oh well I guess now I can finally chase down the chassis vacuum leaks. Locks don't work etc...

Your wife pumping the brakes did a better job anyway...lots of discussion in the past about gravity,air rising, force of cleanout , etc... you should be ' good to go ' now...