1991 R129, brake job, need help - PeachParts Mercedes-Benz Forum

Doctor2687 · #1 07-24-2007, 10:21 PM

So, I tore into my front brakes tonight, using the Mercedes WIS as my guide. (I have done very little work on disc brakes before)
I have purchased new EBC ceramic pads to replace the old worn ones (indicator light was on), as well as new wear sensors.
I have used a punch to get get both pins out, but the WIS is listing a tool that looks like it will slide between the old pad and the pistons, to separate the two, and remove the old pad. Is there another way to do this with out this tool?
Probably a simple question with a simple answer, so thanks in advance for any help!!

Matt

dpetryk · #2 07-24-2007, 10:27 PM

I use a small crowbar or a prybar to open the piston.

waybomb · #3 07-24-2007, 10:56 PM

I usually pull the caliper off the spindle. With the caliper off, I can clean all the crud built up around the pads, and remove any rust that could keep the pads from moving.

But if you don't want to do that, simply place a screwdriver blade between the rotor and the pad, and compress the piston all the way. Pull/pry that pad out, replace with new. Then do the other half. Do the same on the other side. Before you drive the car, you should depress the brake pedal a few times to move the pads toward the rotor, so you have proper braking action.

Mike Miller · #4 07-25-2007, 11:58 AM

Quote:

Originally Posted by Doctor2687

So, I tore into my front brakes tonight, using the Mercedes WIS as my guide. (I have done very little work on disc brakes before)
I have purchased new EBC ceramic pads to replace the old worn ones (indicator light was on), as well as new wear sensors.
I have used a punch to get get both pins out, but the WIS is listing a tool that looks like it will slide between the old pad and the pistons, to separate the two, and remove the old pad. Is there another way to do this with out this tool?
Probably a simple question with a simple answer, so thanks in advance for any help!!

Matt

The tool is a fancy way of depressing the pistons so you can get the pads out. It goes between the pad and the rotor, not pad and piston. You can use anything flat that will fit in there and push the piston (and pad) back. Be carefull not to score the rotor. The pads should come out with a little yank.

Doctor2687 · #5 07-28-2007, 02:34 PM

Ok board brothers, here is the latest:

I got the passenger side apart, using c clamps to open the piston, which then stayed open (this is how it is supposed to work correct?
I got the one new pad in with just a few taps of a rubber hammer. It did sheer just a very small part of the face of the pad off.
Now I cannot get the second pad in. It goes in part way, but then will not go further, I assume I should not force this with a hammer, etc. I believe the piston is still open all the way, but I am stuck.
Any ideas?

Thanks

Matt

tecqboy · #6 07-28-2007, 09:43 PM

When I did mine (1991 300SL ) I had no problem pushing the pistons in with a very large flat blade screw driver. There was ample clearance to install the new pads. As I recall, the piston can be moved in almost flush with the caliper surface. I would not suggest that you force the new pad in. Have you cleaned off all the surface rust? I wonder if the pads you have are thicker than originals? Did the old pads have shims? Do the new pads have shims? Don't forget the anti squeel paste.

Doctor2687 · #7 07-30-2007, 02:02 PM

Thanks guys, I have successfully installed my new pads. I would have still had them apart without all of your help!!

Matt

elau · #8 08-06-2007, 11:46 PM

You don't know how jealous I am right now. I just had my front brake job done by an Indie, both rotor and pad for $419 including tax. You probably saved yourself $275 at the minimum.

lynns · #9 09-16-2007, 02:18 AM

Quote:

Originally Posted by Doctor2687

Thanks guys, I have successfully installed my new pads. I would have still had them apart without all of your help!!

Matt

How many miles are now on your new EBC pads?
Are they the EBC Red?
How is the brake dust?
How often do you clean your wheels now vs. OE pads?

Doctor2687 · #10 09-16-2007, 02:10 PM

Hi Lynn, you are everywhere!! LOL
I have about 600 miles on the pads now.
At first they were putting out way more dust than OEM, and I was not happy.
I realized that this was due to the "Break-in" compound on the pads.
Now they are still kicking dust out, but it gets less every day and is less than OEM.
Manufac. says it can take 1000 miles to fully break-in the pads.
I assume that in a few hundred more miles I will have little to no dust.
Now I am driving the car every day as I want to get time in before the snow flies.
I am cleaning the wheels about every 2 weeks.
(at first I was cleaning them every 2-3 days)

Matt

tswafford · #11 09-17-2007, 12:53 AM

As a seasoned mercedes brake installer (300cd, 85 turbo diesel, 300sl, and 30 years of porsches, I can offer the following tips. I always replace the wear indicators, use white grease on the back of the shoes and the edges (sparingly). I drive the pins with a large nail with the point filed off. I compress the pads with paint stir sticks or cresent wrench handles. Be sure you have removed the master cylinder cap off or you will have a difficult time. always look for fluid leaking on calipers and scratches on the disk. I never resurface disks. They are reasonable to replace as opposed to having a thin disk which would not take as much heat before it warped. You have saved a lot of money doing it your self..buy the best brake pads you can. I have taken to wearing rubber gloves when working on brakes over the last few years. Good luck!!!
Tom Swafford