R BURNS

Need help about MOT is it ok when i take my turbo for its MOT for the garage to test the cars brakes on the brake test rollers as its 4wd would this do harm to the car.

[Edited by R BURNS - 8/23/2002 7:40:05 PM]

Moles Dad

Not 100%, but I think as the scoob has centre diff, it is ok.

My first MOT was done on brake rollers and all was fine

ustolemyname??stevieturbo

iTrader: (1)

When testing a 4wd car on the rollers, the front/rear wheels must not be rotated independantly. All 4 wheels must be turned, or none at all. Auto cars may differ slightly.
The car should be placed onto the stationary rollers, and the footbrake or handbrake applied as appropriate. Only then should the operator attempt to turn the rollers, against the brakes.
Here in Northern Ireland, where all testing stations are government run, I knew of a couple of people years ago, with escort cossies, who had their diffs/gearboxes ruined by ***** who did not know how to operate the system. After a lot of hassle, the MOT centre finally paid up for the damage, although they denied any responibility at first.
Even cars with a rear LSD should not have the rear wheels spun seperately, as it places undue strain on the lsd.
Do a search on MOT, as the guidelines for MOT testing etc, are available on the net.

AndrewC

At my 1 and only scoob MOT the tester said he didn't like to put any 4WD vehicle on rollers and that testers were allowed to test the brakes by feel, which he did - inside the workshop!

Andrew...

PS. As I was trying to stay on his good side I DIDN'T correct him when he said Four-wheel-drive by saying that Subarus were All-Wheel-Drive 4 All-Wheel-Drivers

wrxrob

mot testing stations have a device that sits on the passenger floor and measures the force when braking hard and they can caculate how efficient they are a 4+4 system on any car not just a scoob should never be put on a two wheel brake roller.

ustolemyname??stevieturbo

iTrader: (1)

While a test drive/accelerometer type device may show that the brakes function, they will not tell how well each individual wheel is braked. The only way, is to test each wheel individually, which is how the rollers over here work.Taking the precautions I mention, while still not ideal, is about as safe as you can get. My car just went through MOT last week, and when testing the brakes, at no point did the rollers overcome the braking force, and rotate the wheels, as the brakes were applied before he tried to operate the rollers. He was still able to measure the holding ability of the brakes against the rollers in this way..Had he wanted to take it for a test drive then i would have to have told him.....F**k off, you arent drivin my car, even if it is in a private complex.

scoobyboy

stevie turbo
you can put subarus in rollers even the autos with no damage to them what so ever.provided that it is not used for a prolonged period of time, because the the way the system is designed it is quite strong and with the use of centre diffs there is no strain on anything. and because the wheels turn for such a short period of time no damage will be done. we do them all this way on our m.o.t's and have never had a problem.

ustolemyname??stevieturbo

iTrader: (1)

Well, thats your decision. It even states in the subaru manual, never to rotate axles independantly, and that even tyres that are badly worn on one axle, can over time cause undue strain on the centre diff. Every revolution where there is a difference F-R, will gradually wind up the diff. In most cases no harm probably will be done, but if you ever have to fork out to repair a customers car, then dont say you havent been warned.
The subaru may get away with it more than other cars, due to the VC diff ( coz they are crap ), but if the car has a fixed centre diff, like the fords ( and im sure many other 4wd's ), it would be really stupid to carry out a normal test procedure on it.
WHat would happedn if the subaru you were testing had an uprated centre diff which was almost locked??, or if the adj centre diff was locked?? Would you really be confident trying to rotate one axle?

scoobyboy

as i say in 5yrs of mot'ing subarus i've never had a problem in doing it this way and i've done nearly every subaru out including 22b's with a lockable centre diff. you just have to use common sense and check that it's unlocked. and if a customer has driven one to the test station with it locked they've probably allready bu99ered it.

pele

I had mine tested Saturday, and the man put a device in the passenger footwell & took it along the road to test the brakes.