Club 80-90 Forums

Hi all

MOT due next week..... !

Wanted to be clear on the problems, stresses & strains, of doing the brake test on the standard rolling road.

I mentioned this to the guy six months back while getting my over vehicle tested. He said he wasn't sure but if I wanted they would do a real road brake test but.....

This is very vague & the rolling road would point out any malfunctions in much more detail.

I think this would be good to know.

In short ...rolling road, not recommended !
(it won't work anyway, because your Syncro will just drive off on its own )


If you want to know how each of your brakes does or doesn't work, take out the prop and then put it on the rolling road.

Rolling road not allowed full stop for permanent 4wd or limited slip diffs.

Without taking out the prop, could you test the front brakes without any problems?

No. You must not put a syncro on a rolling road unless its specifically designed for 4wd. They can road test the brakes using a G meter

KarlT wrote:Without taking out the prop, could you test the front brakes without any problems?

No ...as soon as you turn the wheels on one axle, the ones on the other want to turn as well.

If you stop them from turning (putting chucks down or whatever) something (expensive!) inbetween breaks.

Cheers

But now if u had to fit a "decoupler" (not that word)ure brake test problem would be solved.

TSR in bridgewater have a 4wd rolling road in which they can vary the wheelbase to suit the application. £80 for the first hour for tuning. Great way to sort out those niggles. I intend to have a go on it soon and will report back on how good it is ( decoupler not in yet!!) Dont think it can do brakes, but who knows?? and also I wounder if it can analyse the VC power to the front and tourque distribuition. Its brand new and a very nice bit of kit.

these boys http://www.dastek.co.uk/about.htm have a new 4WD rolling road, but they're in Fife which ain't much good unless you're prepared to travel...

incidently I think they quoted me £60 for full diagnostics check which included half an hour on the rolling road...

I think there is some confusion over a rolling road and brake rollers.

Rollers for MOT purposes do not test engine out put.

A rolling road, does however check engine out put, but not brakes.

A 4 wheel rolling road is for checking and tuning power output of cars, not for testing brakes.

There are brake testers out there that do cater for 4WD vehicles, as my local testing station has one.

Instead of just one roller turning, both rollers are set going in opersite diections.
This opposing roation is cancelled out in the diff (and so long as you don't also have a LSD) then no prop movement should occur.

Theres an old thread about this somewhere, but they are out there.

If in doubt, get the Tapley meter out... (declerometer)

In responce to them not highlighting problems with your brakes, what won't it show that you won't already know?
You know if your hand brake is sh!t right?
You know if they judder?
You know if they pull up straight?
And YOU DO SERVICE THE BRAKES DON'T YOU!! so you know they ain't binding and the cylinders aren't siezed.

I would rather use the Tapley than risk damaging a car, and Im sure other MOT testers would say the same, specially as they would have to foot the bill if they broke anything.

Interesting point Mr B and as a prize you get my syncro to MOT when I eventually get it back.

There's also the strain guage type brake testers, one of my local stations has one, where you drive on at speed and brake hard, there are independent starain guages that give you a computer read out for each wheel, and they then repeat the test for the handbrake. If your brakes don't work they crash into the wall at the end of the ramp ! Dodgy bloke runs that place though so I won't go there anymore, not after they tried to charge me a days labour for not fixing my van cos they hadn't a clue, turned out to be the old leaky vacuum take off flexi pipe.

My local guy that I use just goes oh it's got it's prop on ( or not) and sticks the magic box in the cab between the seats and goes for a quick spin or uses the rollers as appropriate...

[quote="Beaker"]There's also the strain guage type brake testers, one of my local stations has one, where you drive on at speed and brake hard,....quote]

Automatic testing lanes they are called. ATL I believe!