But it's not LAW to have ABS is it. All you get is standard brakes if you disable it. They aren't actually deficient without the ABS that's my (pointless) point. There are 80s without ABS and they pass the brake test. It's an enhancement. I believe you Jon, it's just that I have never heard of the ABS being present as part of the test. OK not working on one side, sure, but actually being switched on if you like, if fitted, no. That is a new one for me.
I have been taking my vehicles to this place for 28 years. There is no way they are going to jump out of the rollers. The rollers rotate anticlockwise to the roadwheels. ie they are pushing it backwards when you brake, the car climbs up, but that doesn't matter. Either release the pedal or let it pull you up and out, that's where you are headed anyway.
All getting a bit circular this argument. I know. There are two rollers and they can test left to right or both together. With handbrake applied, or simply natural drag, when they turn the front wheels, the back ones don't turn. The middle diff takes up the difference yes - only the fronts turn. When the back wheels turn on the roller you get the same thing. When they stop one front wheel momentarily, the opposite wheel gets all the movement - not drive, it's not being driven. Other than the bit of coasting you get on an auto on tick over whilst the engine is running for the servo
I just can't see a problem here. Sorry if I am being dense again. All this does is replicate (in reverse if you like) being cross axled with three wheels with no grip. I wouldn't want to try it with the centre diff locked! My 80 is outside on stands with no wheels on. I have just tried this on tick-over. When I pull on the handbrake, the back two stop dead and the front two whizz round like billy-o. Same as in the test which takes 30 second start to finish. These blokes are red hot on MOTs and do nothing else. Absolutely nothing. Just MOTs all day. They have no hesitation to fail or in one case on my old 95, refer to the authorities on the limits of steering rack movement. They're not back street. Not liek the person that passed my 80 just before I bought it. Blind Pugh's auto testing ltd.
Chris