W211 Fitting Rear Discs

[seabadger]

Felt like the first day of spring today so I decided to fit the new rear discs I was saving till the weather got a bit warmer.

Pulled the SBC plug to avoid finger removal and got stuck in. Calipers flew off but I soon had my first panic. Cracking the discs off the hub with my trusted cold chisel wedged against the backplate it soon became apparent that the discs weren't going to jump off.

In fact I soon deduced that I was trying to pull against a spring. These cars never fail to surprise me! The rear disc is a combined disc and drum brake! The parking brake has conventional brake shoes behind the hub which act on the inside part of the disc rotor.

I worked out that I needed to loosen the handbrake adjuster so that the disc/drum could be withdrawn from the brake shoes - but where is it?

A call to a friendly MB parts man told me there is a cam type adjuster inside the drum and a window through the hub so you can poke a flat blade screw driver through to slacken it off.

First I had to get the disc rotor back onto the hub then rotate the disc on the hub to view a 'window' and find the adjuster. At this point I needed to get the car into neutral so that I could rotate the hub. Of course during this procedure the speedo lights up like Blackpool Illuminations. ESP INACTIVE - SBC INACTIVE - EXCESSIVE BRAKE WEAR - REPORT TO WORKSHOP- and of course I can't get it into neutral without engine running and foot on brake.

Lump hammer placed into caliper and fingers crossed I turned the key. The chinking from the rear axle was simply the hub turning inside the disc rotor which was held by the parking brake.

The adjuster is at the dead end of the brakeshoe assembly and spinning the toothed wheel acts as a spreader to adjust the parking brake.

I decided I should change the brake shoes - they looked very thin and a bit chewed from my previous exertions. £58 inc VAT and come with all springs and replacement bolts. In fact the old compared well with the new ones in thickness so I don't think it'll ever need new shoes again. [Currently 87,000 miles]

Plain sailing thereafter and on completion all the alarms and reported failures have gone off the speedo. Just the engine management light stayed on but after a few engine starts it went off (when it realises the problems have been fixed). I had the same warning light after I changed the front discs. [The handbook warns that this can happen.]

So thats another job done and as a bonus I found out how to adjust the parking brake -Just two clicks now!

 

[television]

Just adding to the above,when fitting parking brake shoes,it is better to take up the slack with the wheel adjuster so that the wheel does not turn,then apply the parking brake,next tap the drum quite hard with a wooden mallet all round and this will center the shoes, release the parking brake and do up the adjuster so that the wheel does not turn,a few more taps with the mallet then back off the adjuster so that the wheel spins freely.


I hope that Seabadger does not mind me adding this bit to his excellent thread, he chose just about the hardest car to do it on. Well done.

malcolm

 

[Thegemmesabogie]

If you pull out the little box liner just behind the gearlever then tilt the lid to about 45 degrees you can push a poker thingy (I use a chopstik!)into the little hole which is revealed and the gearlever will come out of park without all the 'key in the ignition' malarky.

 

[seabadger]

There is a double cranked allen key in my toolkit. Like a mini starting handle?

Is this the pokey thing?

 

[television]

Sea badger, as you like doing things your self, would you like to down load the complete technical info for you car,every detail and how it works.

Malcolm

 

[seabadger]

Tell me more? I have taken note of the Russian Sites

I can find the illustrations of all the parts for my model.

Is there more?

Looks like changing the ATF is now on the list of things to do!

 

[television]

I will give you the MB official traning programs, everything from the Can Bus to ABC Sensonic, charging systems and battery.
I will post in the genral section in the morning, in all there is about 400 pages you can down load before it disapears.

Malcolm

 

[Blobcat]

I will give you the MB official traning programs, everything from the Can Bus to ABC Sensonic, charging systems and battery.
I will post in the genral section in the morning, in all there is about 400 pages you can down load before it disapears.

Malcolm

Hmmmmm not thinking of breaking forum rules are you. Premeditated at that :!:

 

[seabadger]

Thanks - I'll look out for that tomorrow!

Cheers

 

[television]

Hmmmmm not thinking of breaking forum rules are you. Premeditated at that :!:

No sir you know that I would not do that, this is an open website, in fact I will put it up tonight.


Malcolm