Sprinter 311 Rear Brakes on fire

[Cnics]

Had an issue with the back brakes earlier. Bit of back lane driving (not fast) and use fo the brakes, arrived at a set of traffic lights and was thankful they turned to green and nobody was infront of me, i was throwing it down the box trying to stop, i was stopping from maybe 50mph in a shorter than average distance but FAR from what you would call emergency braking and it is a damn good job as my foot was on the floor and the van was barely braking.

I was only a few hundred yards from where i was going so drove on steadily to there and parked up, noticing the smoke from both back wheels i decided to leave the vehicle in gear rather than using the hand brake when parked.

They were smoking for a good 5 minutes. the Front ones barely warmer than you would expect. Since cooling down things are back to normal and i have a good brake. But of course this is not the issue here!

Its clear i was on the receiving end of brake fade, but the front brakes were barely warm, could i have a problem on the front brakes (ie them not working properly) causing my back brakes to be working so hard, i regularly transport heavy loads and tow trailers aswell, so this is a major concern.

Rob

 

[Sprint'n'Go]

It is a known problem on the sprinters for the load sensing adjuster to sieze which then allows the rear brakes to work a lot harder than they should. This problem has contributed to a number of accidents where vans have spun out under braking.

see here - http://reviews.ebay.co.uk/mercedes-...erence-which-model_W0QQugidZ10000000001511966

I would try checking for this fault before anything else.

 

[Cnics]

Would make sense, i've had the van 2 years and it has got through half a set of front pads, (done 70k in it). In the same time it is on its 4th Set of rear pads. (they aren't sticking).

The main question is even if the back brakes are doing ALOT, surely the front ones would go some way to stopping the van? the braking effort was poor to say the least and the front brakes barely warm.

Rob

 

[Sprint'n'Go]

My van wears front and rear pads at roughly the same rate (last about 60k) although the rears did have to be replaced slightly sooner than the fronts with the original set. Has your MOT tester never commented on the brakes performance as your rear wear rates are astounding!

It might be that the compensator is simply adjusted badly and is not actually seized. I am not sure of how to set it so a trip to a merc van specialist might be worth while. The compensator is attached to the left side of the rear axle by a short plastic link with 2 ball joints and a steel arm about a foot long that pivots on the shock top mount bolt and connects to the valve with a spring and adjuster bolt.

 

[Cnics]

Never had any MOT failures for brakes, not even advisory notices. Just seems odd, its as if the front brakes are doing sod all. As i say, i've done 70k in the in just under 2 years and it had the first set of front pads (since i've had the van) in January and they were a little over half worn but i was having the front end to bits so i did them anyway as i'd just done the back ones AGAIN, which has been once every 6 months. I'd expect more wear on the back ones than normal as i tow trailers quite often, sometimes (all be them smaller) unbraked ones. But given your 60k per set, and my 35k per set for the back and 70k+ for half a set of front ones, there is clearly something not right.

I'll have a look at the compensator and get it into a specialist if necessary, it'll need something doing to it, i've never had a problem with brake performance until now, impressive if my front ones are doing nothing!

Rob

 

[Hibbo]

I'm by no means an expert (on anything, especially not brakes) but I would guess that if, for what every reason, your back brakes have boiled the fluid, then any pressure you apply will be used up compressing the gas (brake fluid vapour) and NOT operating the front calipers, thus no braking = Brown trousers!

 

[television]

You do also have a tandem master cylinder, if the front one is shot then the pedal can feel spongy and further travel than normal.

Malcolm

 

[Sprint'n'Go]

Malcolm has a point, but I am suprised you haven't been experiencing any back brake lock up when unladen. The 311 doesn't have ABS as standard (although it was an option) so I suppose that a sprinter with ABS wouldn't skid out of control regardless of the compensator condition. Definitly needs sorting as something is far from being right.

Just had a quick look and can't find any info on whether brakes are split front to rear or diagonaly and I don't have time at the moment to go and look at my van.

 

[Ultymate]

I've not had much to do with Sprinters but one question I'd like to pose is, is the handbrake a set of shoes ie a drum brake within the disc as on a lot of the saloons? if so maybe your problem lies with your hand/parking brake it would still heat up the disc assembly. Just a thought

 

[eric242340]

I am definately no expert on vans, but had a problem vehicle like this recently, the owner said it had been like it since new. After a lot of testing we found the rear compensator valve to be sticking. The vehicle only had 40k on the clock and had been checked by the dealers, thats why he brought it to us. After changing the compensator valve both front and back gave sensible readings on the rolling road. But I honestly thought this was a one off problem. I wonder if anyone else has experienced this?

 

[Blobcat]

I've not had much to do with Sprinters but one question I'd like to pose is, is the handbrake a set of shoes ie a drum brake within the disc as on a lot of the saloons? if so maybe your problem lies with your hand/parking brake it would still heat up the disc assembly. Just a thought

That is exactly what happened to an Astra Estate I had. It went in for a main dealer service where they tightened the hand brake. Next day I was going on the B roads out to West Wales I lost all brakes, foot to the floor and no stopping. The handbrake was ever so slightly on which heated up the rear offside boiling the fluid. I went back to Vauxhall who found a service bulletin that 7 clicks was the minimum setting (they had set it to 3!)

 

[eric242340]

That is exactly what happened to an Astra Estate I had. It went in for a main dealer service where they tightened the hand brake. Next day I was going on the B roads out to West Wales I lost all brakes, foot to the floor and no stopping. The handbrake was ever so slightly on which heated up the rear offside boiling the fluid. I went back to Vauxhall who found a service bulletin that 7 clicks was the minimum setting (they had set it to 3!)

Three clicks is what they used to teach back in the 1960s however times have changed and maybe the mechanic who adjusted it is of the old breed. Nowadays ,different cars are different settings. The three click syndrome is ancient (come to think of it so am I:Oops: )

 

[Cnics]

Malcom has a valid point indeed, something i'll look at as the pedal has never been great on it (but nor has it on any sprinter i've driven).

To confirm, yes, the handbrake runs on a set of shoes inside the disc like a drum brake. And the handbrake performance is poor to say the least, This is another possibility.

I think i have an exhaust issue aswell, aswell as the turbo issue, and this, and i've just spent over £750 on it since December, excluding the MOT cost and 12 months tax. All come at once, great since in my line of work Jan-March is nearly dead! Never mind,

Rob

 

[mattkh]

All come at once, great since in my line of work Jan-March is nearly dead! Rob

Just as well. Imagine the van being off road when you have all those deliveries to do.