Combustible brakes??

[LXA]

Right, having got my seized locking wheel bolts removed, I now have this.....
......just got to work out why I appear to have a binding r/o/s brake now?..... couldn't be anything to do with twatting the wheels wiv big 'ommers could it, screwing up sensors or something.... possibly. Not sure how long it's been going on but only discovered it yesterday when fondling the re-torqued bolts and new shiny ones that replaced the locking bolts (burnt finger time!!). I've driven 1500 miles since buying it 6 weeks ago and haven't noticed it previously BUT haven't been fondling me nuts...err bolts either. Also, previous owner provided invoice for last service from MB independent 18 months / 2k miles ago. In addition to service there was a strip down of said brake and rebuild following analysis of apparent heat damage to disc and sensor replaced too..... mebbes it didn't fix it??!! - You never know, I could get an extra 5-10mpg if I didn't have a binding brake!!!
Question - does driving round with a heat generating binding brake lead to fires?? - I've got it booked in for it's next session of bringing it up to standard on 9 Feb. which I think includes a look at the brake. I'm not planning any big journeys twixt now and then, just locals, no more than 10-15 miles at a time. Should I be alright to run with it til then d'ya think or get it in asap ?
No blame will be attached to any advice given which turns out to be wrong..... just wondering.

and also..... is anybody aware of issues of this nature with W164 brakes pleaseta

 

[190]

I would have thought the cause is likely to be a semi-seized piston in the caliper. I would remove one of the caliper bolts so you can swing it clear of the disk and then exercise the piston by pushing it in and then carefully using the brakes to push it out again. A few cycles of that might help free it up. There are proper tools to push the piston back in but you can get by with a G cramp.

The thing to understand is that it's the hysteresis of the piston seal that pulls the pads back off the disk when the brake is released. For that to work the piston has to be free to move reasonably easily. If the piston doesn't pull back then the pads drag on the disk and produce heat. As it's a sliding caliper the other possibility is the sliders are seized but I found that to be less likely on modern brakes.

If you are not up for having a look at the calipers I would drive it as slowly as reasonably practical until it gets fixed.

 

[LXA]

Many many thanks, much appreciated. I have done my own brake servicing in the past but was younger, fitter, more able to deal with the vagaries of the British Winter (yes, even in Cornwall) - unfortunately my cheap 1970's retirement bungalows garage is too small to fit the ML in!! I will try and get it in the local MB Indy ahead of time

 

[grober]

Not sure of the age of your car but many Mercedes models have combination rear brakes-the rear disc being a disc+drum arrangement The handbrake operates by applying small brake shoes by a lever arrangement via a cable mechanism on this drum.The brake shoe return springs can break, the operating mechanism can jam, the handbrake cable can jam--it also has a return spring /equaliser mechanism that can seize meaning one or both rear drums stay on Sounds a bit like that? The discs plus calipers may not be involved except every thing gets hot of course.
REAR WHEEL BRAKE MERCEDES M-KLASSE [Car] [CHASSIS] (EUROPA)

 

[Bellow]

The fire risk is in the assembly getting hot enough to melt the grease in the wheel bearings. If it escapes and contacts the hot disc (I saw a car pass here recently with a disc glowing red hot) it can catch fire.

 

[LXA]

Not sure of the age of your car but many Mercedes models have combination rear brakes-the rear disc being a disc+drum arrangement The handbrake operates by applying small brake shoes by a lever arrangement via a cable mechanism on this drum.The brake shoe return springs can break, the operating mechanism can jam, the handbrake cable can jam--it also has a return spring /equaliser mechanism that can seize meaning one or both rear drums stay on Sounds a bit like that? The discs plus calipers may not be involved except every thing gets hot of course.
REAR WHEEL BRAKE MERCEDES M-KLASSE [Car] [CHASSIS] (EUROPA)

It's a 2006 ml500. Would the parking brake light stay on if it was making contact.
Must admit being a bit heavy footed for the first few weeks until I got used to it..... In fact I got used to it rapidly after getting some feedback applying it that felt like the strand of a cable going ( ahem) - barely apply any pressure now

 

[LXA]

The fire risk is in the assembly getting hot enough to melt the grease in the wheel bearings. If it escapes and contacts the hot disc (I saw a car pass here recently with a disc glowing red hot) it can catch fire.

Yup, that's the one I'm worried about - all sorts of worrying going on now :/

 

[LXA]

Booked in for 0800 tomorrow - just 25 miles to drive today ( everything crossed )

 

[grober]

If 2006 it will be a w164- still has the drumbrake arrangement.
REAR WHEEL BRAKE MERCEDES M-KLASSE [Car] [CHASSIS] (EUROPA)
The warning light switch normally works on the release mechanism[ handle] so if you "release " the handbrake the light will go off even if the mechanism is seized on further back

 

[LXA]

Calliper - collecting tomorrow

 

[LXA]

Aaaand what a difference a day makes.!! I thought there was some kind of AI system in there that knew, generally, when I took my foot off the throttle I'd probably looking to slow down so started the process for me, but no!! It was binding brakes all the time !! .
Fully expecting another 5-10mpg now

 

[LXA]

....aaaaand what a difference it makes to reversing - all of a sudden nice and smooth as to be expected. Previously (presumably under the influence of a seized caliper) it had been somewhat hesitant, requiring and extra bit of welly on the throttle (not advised) then when it finally did get going, not at the speed you'd expect for throttle position by which time it would be time to stop.... ah the joys!!