mot brake rollers?

[missmouse]

anyone heard this thing about 4x4's on mot brake rollers?
Its like if you test an S2 or similar, the diffs will break if only one set of wheels is turned?
Got to be rubbish surely? I had my S2 mot'ed on rollers about 7 times & it never did any harm.
Im reading this on the RS246 forum cos ive got RS4 now (B5) which as far as Im aware uses the S2 g/box & similar 4x4 system ( proper torsen centre diff no daft haldex couplers!)

Simon

[Kieron20V]

Its a no no if its only a single axle roller, will damage the cente diff.

[Rusty]

Been discussed plenty of times. With the Torsen centre of teh S2 you should be OK as the speed of the rollers is low, with a solid diff quattrom Land Rover etc. you're in for a big bill...

[Fat Audi 80]

They never put mine on the rollers at my MOT place. He uses an old skool accelrometer in the passenger footwell...

I don't think it is a particularly good idea...

[Acidburn]

They never put mine on the rollers at my MOT place. He uses an old skool accelrometer in the passenger footwell...

I don't think it is a particularly good idea...

Yup thats what they did with my s2

[bsavictor]

The MOT tester will drive the car on the road, if he is happy, brake test is complete

[Ducky]

They never put mine on the rollers at my MOT place. He uses an old skool accelrometer in the passenger footwell...

I don't think it is a particularly good idea...

Same here with my RS2.

[missmouse]

a few differing opinions here guys!
Ive HAD mine done on single rollers at least 7 times in as many years?
No problems, was I just lucky 7 times & had 7 ******** testers in about 4 different garages?

Any factual reasons as to why the centre diff will break?

[Le S2 Audi]

The MOT tester will drive the car on the road, if he is happy, brake test is complete

So does my guy with both the S2 & RS6....

[madpugger]

Absolute garbage! It only turns the wheel about three times! Not only that, it turns so slowly it makes no odds. You couldn't do it on a power roller obviously.

As for landy's etc, same goes, will do NO damage, IF the diff is locked, it will just push the thing forward off the rollers. The ONLY reason Landrovers are test driven is to check the handbrake. Total cr@p that too, but some wise nut in vosa - or whoever it was - decided that because the handbrake is actually on the rear of the gearbox and not on the wheels, it should be tested on the road!

[madpugger]

Oh, and as far as I am aware, the brake test must be done on rollers as the actual figures are 'needed' to compare sides. The figures are not entered into the system but a road test is not allowed these days AFAIK.

[S-Express]

Oh, and as far as I am aware, the brake test must be done on rollers as the actual figures are 'needed' to compare sides. The figures are not entered into the system but a road test is not allowed these days AFAIK.

it is on certain cars - i have a kit car with an unspecified gross weight so he has to do it on the road...
But completely agree - slow roller speeds will cause no damage....

[dest]

Last year my S2 was MOT'ed and he took it out on the road with the decelerometer or whatever its called.
This year the same tester did it on the rollers.
I asked him why and he said they were all done on the rollers now

[S2central.net]

This has come up loads before... Nothing to fear with Torsen quattro on a single axle brake tester... Speeds are so low that it can cope with things. Some MOT places will just play safe on a permanent 4WD car and do the little road test.

[dubmeister]

Here is the official guidelines:http://www.motuk.co.uk/manual_370.htm

Testers do not usually test permanent 4x4s on the rollers due to the hassle of fkin the car up- and use a Tapley(decellerometer).

When the VT40 (test sheet) is printed now, they give all the listings if that vehicle can be tested using an RBT (usually quattros, and a6s,renaults,passats with the electric handbrake) and any other vehicle specific measuring/testing differences.

When testing you have to check the thickness of brake pads, if less than 1.5mm (measure it!!) then that is a Fail, IF the pads are not visible, either from underneath or through the wheel, then they cannot be failed as you are not allowed to remove any wheels etc to check them!!

And the highest readings you will get on an RBT are when the pads are completely fooked!!!

and dont think that just because the rollers turn slowly they cant cause problems..... ive seen a tester blow a 4x4 centre diff and blown many flexi and solid brake pipes myself after they had been checked underneath(usually rears due to them never getting that much pressure when used on the road!!)

Be thankfull that most testers are intelligent enough to know when a cars brakes are good enough- you wouldnt want to get recovered home from the test station with a blown diff now would you.................and same as a head gasket blowing on the test, you have NO comeback