Looks like it's brake time - PeachParts Mercedes-Benz Forum

The Warden · #1 09-11-2002, 04:14 AM

Well well well...I've noticed the wear pad sensor light come on a few times over the past few days, mainly soon after starting the car i.e. while I'm holding the service brake pedal and releasing the E-brake. So, I'd guess it's a safe assumption that the brake pads are getting a bit thin...and, since I haven't replaced the pads in the time I've owned the car, I'm guessing it's safest to just go ahead and replace the front and rear pads.

First, any suggestions for a pad that's got good braking power and hopefully won't leave too much dust around or make too much noise? Obviously, braking performance comes first, for safety as much as anything else.

Second, any special tools needed for this?

Third, just out of curiosity, are the pad wear sensors on the front brakes only or all 4 corners?

Fourth, I've heard somewhere (I think in the Haynes manual) that there is actually a small drum brake setup in the rear wheels to serve as the parking brake. What kinda maintenance is needed there?

Fifth, if the rotors feel smooth (no gashes, ribs, etc), is there any reason to turn them? Braking feels okay, and I'd just as soon not repack the wheel bearings if the rotors are okay.

Thanks in advance!

speedy300Dturbo · #2 09-11-2002, 05:03 AM

1.) You can't go wrong with Textar, ATE, Teves, or Pagid pads. They are OEM.

2.) A hammer and a punch for removing the brake pad retaining pins, and something to compress the piston with. A large pair of pliers works. So does a big flat-head screwdriver.

3.) One wear sensor per front wheel.

4.) As for parking brake maintenance, do you have sufficient tension in the pedal? Does the car hold itself when parked on an incline? If so, your parking brake is probably fine.

5.) Don't get MB rotors turned. Replace them if they need replacing. Do you have any vibration in the steering wheel when braking? If not, they're probably okay.

Don't forget some anti-squeal paste to put on the back of the pads!

The Warden · #3 09-11-2002, 05:20 AM

1) What's the best source for pads from any of these manufacturers? Assuming all are of similar quality level, cheapest is best.

{added in edit} Maybe I'm just used to 3/4 ton trucks, but man! Those are tiny pads...

2) Okay, cool. Just wanted to double-check.

3) Okay

4) The pedal feels fine, although I haven't tried holding the car on an incline on the E-brake alone. I'd guess it's fine; was just wondering since I'm doing the other parts as well.

5) No vibration, so all is likely well. Just wondering, why shouldn't they be turned?

Also, any good names on the paste? I think the stuff I used the last time I did brakes was Permatex I believe (red stuff, came in a squeeze bottle that kinda looked like a bottle of wood glue; became permanently a part of the back of the pad and any rags I used to wipe excess stuff off), but it didn't seem to help all that much...OTOH, I also used Raybestos pads, which I've heard have a tendency to squeal no matter what you do...

jcd · #4 09-11-2002, 07:02 AM

I got some MB brake paste from my local MB dealer. They sell it in foil packets for about $.40 a piece, or some small amount. It only took about 1 packet per pad.

Get your pads from Fastlane, support the site.

84300DT · #5 09-11-2002, 07:27 AM

here's the parking brake setup, with shoes needing replacement...

P.E.Haiges · #6 09-11-2002, 08:24 AM

Warden,

You may not need rear pads. They usually last as along as 2 sets of front pads. Check the thickness of the rear pads before replacing them.

There's no reason not to turn MB rotors if they need it. They are made out of cast iron just like others. I've had it done it successfully many times.

One of these days, I'm going to have to replace my front pads. They have 120,000+ miles on them and are half worn out already.

P E H

speedy300Dturbo · #7 09-11-2002, 08:51 PM

I prefer using "Permatex Disc Brake Quiet" which comes in a spray can. Cheaper overall than the MB brake paste and works just as well. Plus there's a whole lot of that stuff in one can.

psfred · #8 09-12-2002, 01:43 AM

Rear pads usually last about twice as long as front pads.

Your parking brake shoes don't need to be replaced, they have plenty of material left. What you need to do is apply them while driving once in a while to wear the crud off. Makes them work better, I do it in all my cars.

MB rotors need to be replaced about every third set of pads -- roughly every 100,000 miles. If you can feel a distinct ridge at the outer edge of the rotor and/or cannot see the "dip" between the machined surface where the pads run and the hub, replace. If you don't, the backing plate will jamb up on the anti-rattle spring when the pads get worn, causing the pads and pistons to cock, sticking the pistons in the bore.

Rotors can be turned, but I would only do so to remove extreme scoring. You must check to make sure they are thick enough, and usually if there is deep scoring and or pitting (mine have been sitting for several years....) they will be too thin as soon as you get them clean.

This is exactly the situation I'm faced with on the 280 -- I now have to replace rotors, pads, AND rebuild the calipers, as the inside piston on both sides are stiff up front, and I expect the rears are shot, too. It's a miracle that the kid driving this thing didn't hit someone, it was almost impossible to stop!

Peter

The Warden · #9 09-12-2002, 03:54 PM

Okay, looks like I'm going to get the pads from Fastlane...I suppose I'll pick the least expensive of the four.

Chances are the rears won't need doing; I'll have to pull the wheels to find out for sure. I may just do them to be on the safe side, though, as I do'nt know when they were last replaced.

Also, I don't think I'm going to do them immediately...the light just started coming on sporadically, so I probably have a while longer...I'll wait 'till I get paid again.

Thanks!

Cap'n Carageous · #10 09-12-2002, 04:18 PM

Quote:

Originally posted by The Warden
Okay, looks like I'm going to get the pads from Fastlane...I suppose I'll pick the least expensive of the four.

These are your BRAKES!!! IMHO not exactly the best place to be bargain shopping!!

tjohn · #11 09-12-2002, 07:26 PM

Yes, but The Warden all ready said he was picking from among the four OEM pads. Under those circumstances why not pick the cheapest? Being safe doesn't mean you have to throw away cash needlessly...

The Warden · #12 09-12-2002, 09:47 PM

As Tjohn said, I specifically meant the least expensive of the recommended OEM pads. Pep Boys has brakes for this car for $15 a set, but I'd rather have a set that'll reliably stop the car, hopefully not make noise, and hopefully not make too much of a mess. Chances are the $15 pads won't do all three of those. So, I'm going for the OEM pads.

lrg · #13 09-12-2002, 11:59 PM

Not to nitpick but the front pads actually take four sensor wires, one for each pad. sometimes you can reuse some of the old ones but I usually find that they are pretty much melted into the pad. Chances are the parking brake shoes will last the life of the car if you don't burn them out. They're easy to adjust so if they slip some try adjusting them first. Checking the PB shoes requires you to remove the rear calipers and pull the rotor/drum, probably not a bad idea if you have the time and inclination to do it, it's a very easy job. Also, I've replaced five sets of front pads with OEM and never had to use paste. I've never had a problem with squeeling and the hills of S.F. sure are a good test.

The Warden · #14 09-13-2002, 01:40 AM

lrg, are you saying that I need to replace the sensor wires along with the brake pads? Not a problem, but I'd like to have all my ducks in a row.

Also, does Fastlane have 'em, or do I need to go to the dealer? *shudder*

I had assumed that the sensor wire and/or any connections would come with the new pads...?

Again, the parking brake works perfectly

I was just wondering...

lrg · #15 09-13-2002, 02:05 AM

Warden,
Fastlane will have the sensor wires and they are sold separately (the bad news) but they are cheap (the good news). Just so it's clear, the sensor wire is not the wire from behind the fender to the caliper but the actual sensor that goes into the brake pad. If you haven't seen one, it's a little plastic rod about the size of a pencil head that inserts in a hole in the pad itself. The "rod" is actually a wire, the other end of which you attach to a female plug on the caliper. When the pad wears down enough to expose the wire underneath, it grounds a circuit on the rotor and the light on your dash lights. Since it won't ground evenly at first it tends to flicker and will only go on when you hit the brakes and cause the pad to press hard against the rotor. Usually you have a fair amount of use left on the old pads when you first see the warning light flicker.