Hot back wheel even after MOT pass!

[nufc1975]

Hi all,

I had an issue last week where my back driver side wheel was red hot after a drive. Real hot metal smell + some smoke from behind disc. Car was going in for a service/MOT anyway so I had garage look at that.

Fault found - brake disc showed signs of heating, plus pads were cracked. Cause was handbrake not releasing properly on that side. All shoes & pads replaced plus sensor. Calipers cleaned etc. Mechanic said disc itself was fine to keep so I did.

MOT passed with no advisories or anything.

Drove car home...and...same heat from same wheel.

1) is it fair enough just to hand car back to garage & they'll take another look?
2) anyone got any better advice or ideas?

Seems really odd that it could pass an MOT but I'm no expert!!

 

[mikestrivens]

Parking brake doesn't work on calipers or disk. I wonder if they knew what they were doing.

 

[nufc1975]

...well that's a worry. Invoice says:

Rear brake pads
Brake Pad Sensor
Brake Shoe Kit
Hand Brake Shoes

Mechanic said handbrake wasn't releasing properly on the affected side leading to that damage.

 

[LostKiwi]

Does sound odd. Parking brake works on a drum brake internal to the rear disc. No way the hand brake will influence the disc pads.

 

[nufc1975]

Odd bit for me is the MOT pass straight afterwards. Should I go straight back to em or would you advise caution? Paid £450 for full service, MOT plus that work so keen to get it resolved.

I saw the brake disc myself - it was obviously damaged. Edge was burned red.

 

[mikestrivens]

Was this a Mercedes garage or Mercedes specialist indie or a back street chop shop?

It would help if you put your general location in the CP so we can make recommendations.

 

[nufc1975]

Newcastle upon Tyne.

Was a decent standard dealer - not a Merc garage but they do sell premium cars. I bought the car from them 2 years back.

 

[malcolm E53 AMG]

Does sound like a caliper piston sticking, that would be first on my check list, should be easy enough to see what’s binding, take it back and get them to check it

 

[LostKiwi]

I'd agree with Malcolm. Definitely sounds more like a sticking caliper than handbrake issues.

 

[XJ600]

Park brake cable part seized ?? That's if you use it.

 

[LostKiwi]

Park brake cable part seized ?? That's if you use it.

Discs are nothing to do with parking brake. It's a separate drum brake in the hub.

 

[mioba]

Sounds very much like a stuck calliper. Might be easier to call the RAC or AA if your a member and get them to do it in your drive. It's about a 30 min job.
I had the same on my VW bus years ago. The heat will dissipate into the tyre so be carful with the tyre pressure.
I would be certainly more peeved at misdiagnosis and associated costs.
Let us know how you get on.

Seems like they have repaired the affect rather than the cause.

 

[Ken_R]

Double post. The Forum took ages to accept the posting.

 

[Ken_R]

I saw the brake disc myself - it was obviously damaged. Edge was burned red.

Not so sure about that. Discs are designed to take high temperatures, within limits. Under exceptionally heaving braking they can indeed 'turn red'. It is what they are designed for. Providing it doesn't result in any distortion or cracking, then it should be fine.

There is a conflict here as my understanding is that the Service Brakes are pads (held by calipers) and discs. Whereas the Parking Brake mechanism is brake shoes acting on an [inboard drum]. I'll stand to be corrected.

My thoughts would be that if the handbrake - shoes + drum, were binding sufficiently as to heat the Disc, by conduction, to an extent that such heating was visibly present [at the Disc] then the wheel bearing would also have been subject to such conditions and be at the verge of failure.

I'm inclined to think that the issue has been mis-diagnosed and you have paid for items that didn't actually need replacing, albeit that the Handbrake linkage was probably in need of lubrication anyway.

Brake Shoe Kit
Hand Brake Shoes

Were you given the original items as 'evidence' that they had been changed/needed replacing?

 

[star]

Parking brake doesn't work on calipers or disk. I wonder if they knew what they were doing.

Discs are nothing to do with parking brake. It's a separate drum brake in the hub.

The "drum" part of the handbrake forms part of the disc, so the heat from a sticking shoe will transfer thru out the discs.

 

[nufc1975]

Hi - update here.

Took car back in & was fine (meaning cold wheel) on drive back in. Garage checked it - they'd apparently checked the piston already - and took it for test drive. Car was ok.

They claimed that after the handbrake fix, that they had fitted the replacement part a little too tight maybe & when it 'bedded in' it may have rubbed. So they adjusted slightly.

Car run fine on drive home last night form garage & was ok this morning.

 

[Craiglxviii]

So they didn’t do the job right the first time.

 

[XJ600]

Discs are nothing to do with parking brake. It's a separate drum brake in the hub.

The park brake drum is part of the disc.

 

[EmilysDad]

The park brake drum is part of the disc.

But as LK says, the two braking systems are completely separate.

 

[nufc1975]

So they didn’t do the job right the first time.

That is my conclusion. They even had the cheek to tell me that the work on the second day was free of charge...