MOT Brake Test on a 4x4

[Camo]

MOT brake testers.
With these machines only testing the front or the rear, and not all four together, is this likely to do any damage to the four wheel drive system??

 

[stevieturbo]

nope, its quite safe.

 

[Camo]

just heard that on a st185 gt4 it can do abit of damage from the guys from
gt4oc

 

[stevieturbo]

Im sure they dont have the same machines in England etc, as they do here.


4wd vehicles get tested day in, day out.

I dont see the GT4 having such a sophisticated 4wd system, that there would be a problem

 

[Camo]

cheers stevie

 

[alan_d]

again, its based on hearsay, but I was told au contrere by a very highly reputed tuner. Apparently its quite tough on the vehicles transfer box?

 

[alastair]

I dont know about Gt4's but i do know that volvo AWD vehicles cant be lifted on a dolly if they are being towed as this fooks up the 4WD system.

 

[Camo]

I dont know about Gt4's but i do know that volvo AWD vehicles cant be lifted on a dolly if they are being towed as this fooks up the 4WD system.

I think its the same with all awd vehicles

 

[Coog]

Id just knock mine into neutral on the transfer box for being towed. Cars without the ability to do this manually couldn't be towed tho

 

[Gaz]

I was just going to say, surely when put in neutral the transfer box is effectively disengaged?

Gaz

 

[TheLarneMan]

The brake testers are put into 'pseudo 4WD mode'. For all the length of time the car is on the tester no damage will be done. Although for, say, towing a 4WD car any distance on the road would be bad for it. I was told if my Impreza ever needed towed to remove a fuse or something - I'm sure someone will clarify this.

My Impreza was used to help calibrate the equipment in most of the MOT centres and the brake testers did it no harm. Brendy should know a bit more about the brake tester and 4WD cars - it's been a long long time since I did any work in the MOT centres.

 

[Camo]

but going 2 be engaged when on the rollers

 

[Camo]

its 50/50 i have heard people say its ok and other say dont even dare do it because its permenant 4wheel drive and any decent MOT tester should know this. If he says it does then he dosent know his stuff.

 

[Cess]

They should have alernative facilities for 4WD cars. The GT4 has viscous centre diff I think, which *could* be damaged by prolonged use on the 2WD rolling road.

Generally speaking, the boys on GT4OC know their stuff. PM Alan_M on there,he knows the score

 

[stevieturbo]

Although for, say, towing a 4WD car any distance on the road would be bad for it. I was told if my Impreza ever needed towed to remove a fuse or something - I'm sure someone will clarify this.

WRONG !!!!!

the fuse thing only applys to automatic Imprezas. Do not tow any permanent 4wd car, with only 2 wheels on the ground ( unless you remove the propshaft )

They should have alernative facilities for 4WD cars. The GT4 has viscous centre diff I think, which *could* be damaged by prolonged use on the 2WD rolling road.

Generally speaking, the boys on GT4OC know their stuff. PM Alan_M on there,he knows the score

The MOT test is safe for 4wd cars. Anyone who puts a 4wd car on a typical 2wd rolling road, is an idiot, and deserves damage.

The MOT test is not a rolling road, and Im pretty sure at no point during the test, do both wheels rotate in the same direction, at any 1 time.
It is a set of rollers, that can spin your wheels, in order to test breaking efficiency.

So all diffs, are working quite normally, with no undue loads on them, and certainly nowhere near the loadings that would be placed on them during abusive driving.

 

[Cess]

The MOT test is not a rolling road, and Im pretty sure at no point during the test, do both wheels rotate in the same direction, at any 1 time.
It is a set of rollers, that can spin your wheels, in order to test breaking efficiency.

So all diffs, are working quite normally, with no undue loads on them, and certainly nowhere near the loadings that would be placed on them during abusive driving.

Cheers lad. So the rollers only turn one wheel at a time?

 

[stevieturbo]

Almost certain they do. This is partly so it wont do any harm.


Unless of course you have a welded diff.

But for stuff like that, I was told the rollers have built in protection, that if there is any undue resistance felt, it automatically throws up warnings.

 

[Marc]

Cheers lad. So the rollers only turn one wheel at a time?

as far as i remember, yes, it only checks one wheel at a time

as when i was putting my car through MOT the though came on me about the transfer box.. but it was fine in the end

 

[Cess]

Cheers Stevie and Marc.

 

[TheLarneMan]

WRONG !!!!!

the fuse thing only applys to automatic Imprezas.

There you go - I knew someone would know the proper story behind the fuse myth.