Burning rubber smell from back wheels Zafira?

Legacy_user

I've had this issue pretty much since I got this car a couple of years ago, I had it into the garage twice and on both occasions got told it was to do with a build up in the emissions system and in order to clear it I'd need to do a good clear out on the motorway IE drive at 70 mph or above for a good 15 mins, apparently quite common in this car, well we've done that and can't say it improves it any, and I am no mechanic but I don't buy that theory anyway.

When you stop the car the back wheels start ticking lick they are cooling down, I threw a bottle of cold water over them once and steam came of, as I say I am no mechanic so bear with me when I try to explain this, behind the alloy there is a disc, it seems to be this thats causing the issue, there is also something rubber attached to this which I presume to be the brake and hence the burning rubber, but brakes checked and they are fine.

The brake disc thingy is also rusted, would this make a difference?

So anyone any ideas?

Miles16v

Its normal for brakes to get hot as they are turning moving energy into heat, but if you've been driving gently then you wouldn't expect them to be red hot. If they are binding, so that the brakes are constantly on, then they'll get too hot and smell. I would have thought this would be the first thing the garage would check.

Jack it up and see if you can spin the wheels freely (with the handbrake off).

Rusty discs are very normal, but not on the braking surface. The braking surface gets cleaned regulary by the brake pad.

The rubber thing would be a a brake pipe that carries the brake fluid to the caliper, if that is rubbing on something it would wear through quickly and failure would be bad news. They are designed as such that they dont rub.

Strider590

nirelandguy wrote: »

I've had this issue pretty much since I got this car a couple of years ago, I had it into the garage twice and on both occasions got told it was to do with a build up in the emissions system and in order to clear it I'd need to do a good clear out on the motorway IE drive at 70 mph or above for a good 15 mins, apparently quite common in this car, well we've done that and can't say it improves it any, and I am no mechanic but I don't buy that theory anyway.

It's not non-sense, cars need a good run every now and then, especially if diesel and fitted with a DPF (diesel particulate filter).
Failure to do so in that case WILL eventually result in thousands of £ in repairs/replacements.

nirelandguy wrote: »

When you stop the car the back wheels start ticking lick they are cooling down, I threw a bottle of cold water over them once and steam came of, as I say I am no mechanic so bear with me when I try to explain this, behind the alloy there is a disc, it seems to be this thats causing the issue, there is also something rubber attached to this which I presume to be the brake and hence the burning rubber, but brakes checked and they are fine.

The brake disc thingy is also rusted, would this make a difference?

So anyone any ideas?

Brakes get warm, it's normal..... But check your not leaving the handbrake on, and that the rear brakes haven't seized..... Have the pads been replaced recently? Perhaps they forgot to rewind the callipers? or fitted poor quality parts?

Never throw water onto your brakes, it's just like tempering a knife/sword blade, on the molecular level metal has a crystalline structure which expands with heat and contracts when cooled, making it cool rapidly makes the metal harden, great quality in a sharp knife blade, but not great on brake discs that have to cope with the torsional stresses of stopping a 2 tonne vehicle. They could crack a break apart..... Conversely, cooling just one spot, makes that bit of metal contract while the rest has expanded and thus causes warped discs.

It's also vital to make sure nothing is touching your tyre's, by this I mean broken suspension springs that like to jab themselves into the tyre and eventually cause a blow out.

You could do your own check by leaving the car in gear (hand brake off), jacking the rear end (enough to get the road wheel of the ground) and turning each wheel by hand to check they rotate freely.

reheat

nirelandguy wrote: »

... I threw a bottle of cold water over them once ...

Please do not do this again! Brake drums and discs are (or used to be at least, probably still are) made of cast iron, which is very tough but also very brittle. Sudden temperature changes can cause them to shatter suddenly and send chunks of metal out like a hand grenade! It's for this reason that aircraft brake fires have to be tackled with dry powder extinguishers.

Norman_Castle

Compare the temperature of all wheels by touching the wheel rim or wheel nuts, NOT the disc, you will burn yourself if you do. Wheels on the same axle shold be the same temperature, front wheels are normally hotter than rear.

mikey72

reheat wrote: »

Please do not do this again! Brake drums and discs are (or used to be at least, probably still are) made of cast iron, which is very tough but also very brittle. Sudden temperature changes can cause them to shatter suddenly and send chunks of metal out like a hand grenade! It's for this reason that aircraft brake fires have to be tackled with dry powder extinguishers.

No worse than driving through a ford though, and I've done that enough times with no problems.

reheat

mikey72 wrote: »

No worse than driving through a ford though, and I've done that enough times with no problems.

I hope it wasn't my Ford you drove through!

It's just a common sense safety thing. If brakes have been binding and are much hotter than normal, and suddenly get doused in water, then they might shatter, and you would not want to be near them if they did. If all working normally then no problem. But the OP might be having problems with brakes binding, hence the warning.

poppasmurf_bewdley

I remember reading in a motoring magazine many years ago that braking from 70mph to zero generated enough heat in the brakes to boil a pint of water, which shows you how hot they can get.

It does sound like a classic case of rear brakes binding. As has been said, jack the car up and see by trying to turn the rear wheels with the handbrake off. Chock the front wheels and put the car in gear before you do it though.