removing rear brake rotor - PeachParts Mercedes-Benz Forum

funola · #1 05-09-2007, 02:41 PM

After removing the caliper, and removing the long 13mm center hub bolt, should the rotor then come out? Are there other bolts that need to be removed.? I am rebuilding the calipers and want to have a look at the emergency brake pads while I have the calipers out. TIA

TX76513 · #2 05-09-2007, 02:50 PM

Not sure about your W123 but the center axle bolt does not need to be removed on a W126. If you are having trouble getting it off - get a small sledge and a 2 x 4 and bang around the corners it's just rust seized.

cavaliers16 · #3 05-09-2007, 03:19 PM

The center bolt does not have to be removed. Just look through one of the lug holes for the parking brake shoe adjuster (starwheel type thing) and back the parking brake off. For the drivers' side rear wheel, turn the wheel up, for the passengers' side wheel, turn the wheel down. Then use a hammer to give it a quick bang- it should pop right off. Remember to readjust the shoes when you are done.

rrgrassi · #4 05-09-2007, 03:54 PM

Use a dead blow hammer or a 2x4 with a regular hammer so that you do not damage the rotor surface.

tobybul · #5 05-09-2007, 03:59 PM

Quote:

Originally Posted by cavaliers16

The center bolt does not have to be removed. Just look through one of the lug holes for the parking brake shoe adjuster (starwheel type thing) and back the parking brake off. For the drivers' side rear wheel, turn the wheel up, for the passengers' side wheel, turn the wheel down. Then use a hammer to give it a quick bang- it should pop right off. Remember to readjust the shoes when you are done.

Since I adjusted mine recently, I still recall that the star can be found at the 11 o'clock position.

funola · #6 05-09-2007, 04:30 PM

Thanks for the replies. I got it off before reading them. I could see that the center bolt did not have to come out. I banged on the rim of the center hub while pulling on and rotating the rotor and slowly broke the rust seizure and it came out. My parking brake pads are fine. The star adjuster is at 2 o'clock position on the passenger rear. I adjusted it and now have good parking brakes.

I have another problem though. I can't get the metal brake line to brake hose off due to rust. I sprayed plenty of penetrating oil and it didn't help. I am using an 11 mm open end and the nut is rounding off. I need to get a 6 point 11 mm crow foot or a special brake wrench that has more support than an open end wrench. Not going as smoothly as I like. The RR caliper rebuild went ok, some surface rust on the piston and cylinder surfaces which cleaned up ok with 1200 silicon carbide wet/dry paper, no pitting so I think it will be fine with new seal and boot. Still have to do the other side.

rrgrassi · #7 05-09-2007, 04:33 PM

You need to get flare nut wrenches. They are 6 point with a slot cut in them so that the line can pass through.

Benzcrusher · #8 05-09-2007, 05:05 PM

A quick blast from a torch will help loosen the nuts, I just did all hoses on my 240D, after being on the car for nearly 30 years even the flare nut wrench had a hard time....

funola · #9 05-09-2007, 05:34 PM

I did try hitting it a few times with a propane torch but it didn't help. I didn't heat it too hot so as to not melt the hose and end up stranded without brakes.

I put the wheel back on, drove to autozone and advance and neither one has a set of flarenut wrenches with an 11 mm (they have every other sizes, figures). Sears has a set but expensive at $$35. Guess I'l have to swallow it.

Wheel on/wheel off, wheel on/wheel off. This job is taking too long.

pmckechnie · #10 05-09-2007, 05:45 PM

11 mm and 7/16 are the same size.

funola · #11 05-09-2007, 09:27 PM

I bought a set of Craftsman metric flarenut wrenches, which didn't get the nut off, just rounded it off completely. Now I'm faced with cutting the line, getting a new nut and making a flare. I think its a bubble flare? Can someone confirm? Is the line 1/8 or metric? Is it steel or copper?

Anyway, the old hose is still in there. I managed to rebuild the drivers rear caliper also, replaced the hose without problems, buttoned it up before dark and test drove. The pedal is softer than before the rebuild. EitherI didn't get all the air out or the soft pedal is from the hose weakened by heat? I hope it doesn't blow when I'm driving eeek!

sokoloff · #12 05-09-2007, 09:38 PM

There may still be hope. Try using a Vise Grip LW4 or an LW7 if it will fit. It may grab the line enough to get it to loosen. The worst case is you'll still have to replace the hard line.

Mustang_man298 · #13 05-09-2007, 11:15 PM

Quote:

Originally Posted by funola

Anyway, the old hose is still in there. I managed to rebuild the drivers rear caliper also, replaced the hose without problems, buttoned it up before dark and test drove. The pedal is softer than before the rebuild. EitherI didn't get all the air out or the soft pedal is from the hose weakened by heat? I hope it doesn't blow when I'm driving eeek!

Those are both possible options, however if the caliper had been seizing or sticky before, that would also make the pedal feel harder than normal, which happens slowly over time so you don't notice, until you repair it and now it suddenly feels mushy...

funola · #14 05-10-2007, 03:26 PM

On my 83 the star adjuster is at 11 o'clock on the drivers rear but at 1 o'clock on the passenger rear.

Quote:

Originally Posted by cavaliers16

The center bolt does not have to be removed. Just look through one of the lug holes for the parking brake shoe adjuster (starwheel type thing) and back the parking brake off. For the drivers' side rear wheel, turn the wheel up, for the passengers' side wheel, turn the wheel down. Then use a hammer to give it a quick bang- it should pop right off. Remember to readjust the shoes when you are done.

funola · #15 05-10-2007, 03:33 PM

I called around but noboday has a Vise Grip LW4 or LW7. I took my regular vise grip w. the flat jaws and with a Dremel w cutoff wheel made two 90 degree notches in the jaw so it can grip the nut without slipping, with a long extension on the flarenut wrench on the hose, it finally cracked free and I was able to replace the hose. Fawking about time

Maybe if I used Flarenut wrenches to start with I would not have encountered so many problems.

Anyway, I bled it and now the pedal has a nice firm feel.

Quote:

Originally Posted by sokoloff

There may still be hope. Try using a Vise Grip LW4 or an LW7 if it will fit. It may grab the line enough to get it to loosen. The worst case is you'll still have to replace the hard line.