W221 Park brake drum brake adjustment ?

[Botus]

Hi,

on the rear of the W221 they get a small set of drums inside the rear brake discs to take care of the electronically applied, park brake duties. on the parts drawing there is an adjuster wheel, but its cold and miserable and not really keen to play if I don't know how to do the job.

playing at the weekend there is a mode in xentry to sort it out - "only if new brake shoes are fitted". So I don't know if its auto adjust or its some set up to complete after you mechanically got it sorted, so it leaves the electronic actuator happy.

doesn't any one know what to do ? all of a sudden its not as happy to hold on my relatively steep driveway as it was

 

[mioba]

Dont you have put the car in P first before the handbrake.

They will definately auto adjust. Normal pure mechanical drum brakes have an auto adjuster for the last 40 odd years.

I would be a little aprehenaive playing with them manually. Far to many electrics communicating all the time.

 

[noonboots]

The actuator motor pulls the cables to operate the brake shoes. Certainly on the older cars there was an adjuster inside the drum like most other Mercs. You may have to deactivate the electric brake so that it doesn't keep trying to operate the motor when it's in park.

 

[Botus]

you can park up and never use the park brake if that's your bag - its auto off - its never auto'd on

part 160 - do you think there's a hole in the back plate that means u can see / get at it ?

 

[Botus]

strange - last weekend "I might have" flashed the later software at my handbrake module....

this weekend I parked on a flat bit, put in park and took the key out, when I turned it back on the park brake was on.... so now need to work out if it can put itself on with some more testing - don't recollect doing it ???

 

[Blobcat]

strange - last weekend "I might have" flashed the later software at my handbrake module....

this weekend I parked on a flat bit, put in park and took the key out, when I turned it back on the park brake was on.... so now need to work out if it can put itself on with some more testing - don't recollect doing it ???

I was driving my eldest’s A-Class recently and noted that the parking brake applied itself when I put it into park then opened the drivers door with the engine running.

 

[Botus]

ha - there's a story

still chasing a bug on mine re no fade for audio with nav or traffic overlay - now suspect they broke it in their first ever rear sam update in 2006 - 6 iterations on they still never knew they deleted the best feature on the car !!! - I have been taking EVERY module back to the iteration it was on prior to the mute fault turning up.... gone back 3 revisions on the rear sam and its still not back... and you def don't want the one they offer SCN the legit way as its dangerous - as the active cruise MOSTLY forgets how to brake in time...

and putting the cluster back to the pre purple LCD fix (that never fixed anything....) took away this (which I'd got used to)....if the car is running but stationary and you open the door it applied park (on the gearbox)... but back on the original software it can roll away and only applies park with the key removed

 

[noonboots]

you can park up and never use the park brake if that's your bag - its auto off - its never auto'd on

part 160 - do you think there's a hole in the back plate that means u can see / get at it ?

They're adjusted through the wheel bolt hole. There's no hole in the backplate.

 

[Botus]

thanks, that sounds like fun

 

[noonboots]

thanks, that sounds like fun

It's actually quite easy once you locate it.