W211 rear brake change

[ChrisEdu]

So, maybe this should be in my other thread, but thought I'd go for a separate one as the issues encountered are not linked to the front brake work that I did.

Granted, trying to work on a car with a bad head and painful joints is probably not a good idea, but with the upcoming weather, I felt it best to crack on.

Having done the front brake discs and pads, I though the rears wouldn't be too much trouble. Boy, was I wrong!?

So, the wheel came off easily enough - no surprise, but that was the last easy bit!

Tried to undo the Torx head bolts on the calliper mount - bam, busted Torx bits! After many naughty words, I decided to just undo the calliper bolts, at least they are 'normal' bolts.

Bloody hell! Who tightened them!? They were an absolute pig to loosen, let alone remove. Anyhow, eventually got them out, top tip, unclip the mount for the cables from its little perch - makes it much easier to get a decent wrench on the top bolt head.

Next job, remove the disc. Easy? No!

Again, my Torx bits got eaten alive! It was looking like I might have to drill the fixing as the head was totally mashed, Eventually, I used a broken Torx bit, and a small club hammer to muller it into the head, and finally removed the fixing.

Hooray, I thought, I'm on the home straight! Ha! Some hope! Next issue, the parking brake.

According to my Haynes manual, I should have been able to see a part to wind with a screwdriver, to loosen off the parking rake. Yeah, as if! I tried, and tried, and tried to find it. Find Lord Lucan would be easier! So, I thought, let's try just popping the brake from the lever in the cockpit, having put some wood in front of the wheels, to stop the car rolling forward.

Having done that, I popped the lever and.................

Crash!!!

Down it came a tumbling! The car roller backwards instead and came off the jack. As you can imagine, many, many, many bad words were emitted, along with much panic!

Having finally got the car back up, it looks like there was no serious damage done, just a few marks on the side skirts and some cracking of an under tray that I'd hung the calliper off.

So, as the light was now fading, along with my will to live, I have now called it quits for today.

Can anybody please help advise me how the hell to get the job done? Would I be able to safely take the parking brake off if I raised the whole backend and supported it on axle stands? If not, where the hell is the adjuster to wind back the parking brake shoes?

Sorry for the long post, but I have been on the brink today trying to do this.

 

[E55BOF]

If the car rolled backwards with the front wheels chocked, it needs to be facing the other way down the slope. Chock the front wheels securely, raise the rear with a trolley jack under the diff, and put axle stands under the rear jacking points under the sills.

The parking brake has to be released to free the rear discs, but if there's a lip on the 'drum' part of the unit, it can well be a bugger to get the disc off anyway.

 

[whitenemesis]

Doesn't really matter which way the car faces, if down slope chock the fronts with the chocks in front of the wheels and if facing downhill behind the front wheels.
Ideally do the job on the flat and place chocks in front and behind the wheels, especially if one expects to apply a little 'persuasion'
Never use the side jack when doing this sort of job. Always use axle stands and chocks

 

[MrGreedy]

The parking brake shoe adjuster is usually accessed with a small flat screwdriver though a small hole in the front face of the disc hub, where the alloy wheel mates.

 

[ChrisEdu]

The parking brake shoe adjuster is usually accessed with a small flat screwdriver though a small hole in the front face of the disc hub, where the alloy wheel mates.

Yeah, that's what Haynes says, but I'll be damned if I can find it!

 

[ChrisEdu]

If the car rolled backwards with the front wheels chocked, it needs to be facing the other way down the slope. Chock the front wheels securely, raise the rear with a trolley jack under the diff, and put axle stands under the rear jacking points under the sills.

The parking brake has to be released to free the rear discs, but if there's a lip on the 'drum' part of the unit, it can well be a bugger to get the disc off anyway.

So, it's safe to jack on the rear differential? Got to admit, I couldn't see much other choice!

 

[MrGreedy]

Yeah, that's what Haynes says, but I'll be damned if I can find it!

Take the retaining screw out, remove the disc and see if you can see the adjuster mechanism with the disc removed? It should look like a little cog. Maybe it's had new, but incorrect discs fitted without the hole?

 

[Carabind]

Mmmm. I did the rear discs and pads on my 2012 a class yesterday. One side was stuck, I had to cut a slot into the tire screw an tap it round and the disc was stuck on the hub but the whole job was done within two and a half hours. Either you have been unlucky , or you need to find a mate to help you. it is quite worrying that the car rolled off the supports ........you did have it on axle stands didn’t you ?

 

[OneForTheRoad]

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Put the car in park let it roll an inch , then jack it up.

 

[pmcgsmurf]

Sounds like a right pain in the behind.

I can't figure out how the car rolled from the description.
Did you have it on axle stands at the rear on both sides with the parking brake still on?
If so releasing the parking brake should not have made any difference.

You need to have the parking brake off to start on the rear if removing the discs.
I usually chock it on the front wheels but would not do it on a slope.

That little adjuster is a pain to find if you do not know where it is, next thing with finding it will be which way around it spins, best to look at a picture of the shoes to understand this.






You will likely find very little wear with the shoes.

 

[ChrisEdu]

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Put the car in park let it roll an inch , then jack it up.

Good video however, my disc has no grommet! I only have the wheelbolt holes and the disc retaining screw hole.

 

[W1ghty]

Good video however, my disc has no grommet! I only have the wheelbolt holes and the disc retaining screw hole.

Send us a pic of your disc buddy

 

[MrGreedy]

Good video however, my disc has no grommet! I only have the wheelbolt holes and the disc retaining screw hole.

Have you taken the disc off to inspect what is underneath as per post #7?

i.e. to check that the disc is not the incorrect type.


If it looks like the good pictures pmgcsmurf posted, then the disc should have a hole and you have the wrong disc.

 

[pmcgsmurf]

Very unlikley you will ge the disc off without backing the shoes off.

Simple process to adjust these through the wheel bolt hole.

 

[MrGreedy]

Simple process to adjust these through the wheel bolt hole.

Didn't know that. Useful to know.

 

[OneForTheRoad]

Didn't know that. Useful to know.

Yes the hole makes easy access to the adjuster, there's no need to drill the disc.

 

[MrGreedy]

Yes the hole makes easy access to the adjuster, there's no need to drill the disc.

Drill the disc?
Why would the disc need to be drilled?
I've checked though the posts, and no one mentions drilling the disc as far as I can tell?
The issue appeared to be the Op not being able to slacken off the parking brake cog adjuster via a dedicated hole in the face of the disc boss/hub area, but pmgcsmurf pointed out this can also be done through one of the wheel bolt holes.

 

[ChrisEdu]

This is what I have to contend with (taken before getting the caliper off, not that that adds any extra holes!)
Visible are the five holes for the wheel fixings, plus the Torx head fixing that holds the disc.

 

[W1ghty]

There are 5 holes to access the adjuster

 

[ChrisEdu]

Sounds like a right pain in the behind.

I can't figure out how the car rolled from the description.
Did you have it on axle stands at the rear on both sides with the parking brake still on?
If so releasing the parking brake should not have made any difference.

You need to have the parking brake off to start on the rear if removing the discs.
I usually chock it on the front wheels but would not do it on a slope.

That little adjuster is a pain to find if you do not know where it is, next thing with finding it will be which way around it spins, best to look at a picture of the shoes to understand this.

View attachment 102869

View attachment 102870


You will likely find very little wear with the shoes.

I presume those photos show what you get after removing the brake disc?