Looking for tips on replacing front and rear disc pads on an ML 320. Anything special I should look for and any special considerations? Thanks in advance (rotors are in great condition but pads are getting kinda low)...

Thanks for the help...

I'm right there with you. My pads should be here from FastLane any day now.

I recently changed the front pads on my 99 ML320 and used these directions that I got from the M-Class mailing list, they should be helpful.

>>
I just did the front brakes on my ML320 on Sunday, so the details are still
fresh.

Block the back tires before jacking up the car, as well as applying the
emergency brake. Without the emergency brake on, once one tire leaves the
ground, the transmission will no longer keep the car from rolling.

>>Another helpful trick is to remove the brake fluid reservoir cover. This
>>makes it noticeably easier to force the pistons back into the calipers. If
>>the fluid level is not near low, make sure to check and siphon some out or
>>it will overflow causing undesirable corrosion! I usually siphon some out
>>anyway and check after retracting the first piston or two.
>>When you're all done, top off with fresh clean fluid if necessary (usually
>>not).


Remove the wheel.

If you're working on the left front, pull the brake wear sensor lead out of
the connector at the top of the hub assembly.

As you look down the inspection hole, the inner brake pad has a tab that
projects upward. Using a large screwdriver or pry bar, firmly push that
pad toward the center of the car. You need to push the piston in the
caliper back into the caliper body in order to have sufficient clearance
when reinstalling. Now's the time to do this, because it requires
considerable effort and is much easier with the caliper still bolted to the
hub. Another approach is to use a large C clamp after the caliper is
removed, but I didn't have one large enough. You need to push the piston
almost completely flush with the caliper inner surface, which will leave
about a 1 inch gap between the old brake pad surface and the inner face of
the brake rotor.

Using a T-40 torks socket, unfasten the two bolts that hold the caliper to
the hub. These are on the inside of the caliper, inside some rubber
covers. I noticed in one of the on-line descriptions of this job, the
fellow referred to this as hex or allen sockets. You must use a troks or
you will damage them.

After loosening the sockets, use your fingers or a small screwdriver to
pull the bolts clear of the caliper.

Lift the caliper off the hub and away from the rotor. You may have to pry
gently on the lower part of the caliper to get it free, but lots of force
isn't needed. Turn the caliper over and lay it on top of the hub, being
careful to not let the caliper hang by the brake fluid hose.

Pull the inner brake pad out of the caliper piston.

Remove the outer brake pad by prying it up out of the caliper. I used a
screwdriver in the holes in the caliper, beneath the pad retaining spring
clips.

Put the new inner pad onto the caliper piston. There is some brake rattle
paste that comes with the new pads. I didn't know where to apply it, so I
put it on the surface between the caliper piston and the pad. I don't know
if that's the correct place.

Slide the new outer pad onto the caliper.

There are some stainless steel clips that come with the pads. Pry the old
clips off the brake hub, and press the new clips on. Use one of the old
pads to ensure that you have completely seated the new clips onto the hub.
If you don't seat them completely, the caliper won't go on and it won't be
obvious why.

With the new pads and clips installed, rotate the caliper back and slide it
into place. This will be when you discover if you pushed the piston far
enough into the caliper. On one side I had to use a block of wood between
the new pads to push the piston in further, with considerable effort and
vile mumbling.

Put the caliper back in place. Requires some prying and rocking to get the
new pad tabs resting against the new clips, but nothing too extreme.

Tighten the two bolts that hold the caliper to the hub. I don't know what
the torque spec is, so I made them firm but not too tight. (How's that for
guidance?)

On the left, connect the brake wear sensor wire.

VERY IMPORTANT! Before starting the car, you must push the brake pedal
several times to push the new pads against the rotor. If you forget this,
the first time you try to use the brakes, all the pedal travel will go to
moving the pads in place and not to stopping the vehicle!! At a minimum
this will result in substantial fright, and may result in worse. I always
go and push on the pedal several times even before putting the wheel back
on, to make sure the pads are in place, and to check for leaks.

Put the wheel back on.

This job took me 1 1/2 hours for side one, 15 minutes for side 2. I suspect
that this should be a 30 to 45 minute job.

Well, I just did mine, and after reading the previous post, noticed one ommission. There is an arched metal tab on the outboard pads that faces the rear of the car. To get the caliper back on, you have to start with this tab (spring) being stretched so as to allow the thing to rest against the underside of the pressed on metal slides. You will see what I mean when you do it. I too took about 1.5 hours studying/replacing the first side and 20 minutes doing the other side.

I relieved the caliper pressure with the bleeder screw (10mm wrench). Piston went in very easy then. The only other tool needed was the Torx bit.