While we are discussing trans. brake testing on the MoT, there is an issue at present with the information given by the new MoT computer system regarding late type Land Rovers with the diff in the transfer box, ie. 90/110, Range Rover, etc. Apparantly, it tells the tester to test the trans. brake at 20 mphon a flat surface, this will do horrendous things to the drive train and when one owner saw and heard this take place he nearly lynched the tester. As LR state, that type of brake should not be used whilst the vehicle is moving.
I have seen a trans. brake drum explode on a Bedford MK, the results looked like a hand grenade had exploded under the axle, both tyres punctured and shrapnel straight through the timber board floor of the body and out through the canopy top. Now tell me it is safe and correct to use these brakes whilst in motion, test or otherwise. When testing comes down to it, the manual is only a guide, because different vehicles have to be assessed on their various designs, what it boils down to is common sense and experience, something the younger testers do not have. I took a customer's Bedford MW for testing last year and when it came to the brake test, the young sprog said it was too old for testing the brakes. I told him he was wrong and that he should do it. As the brakes were in top order it came out high on the scale and he was "amazed", and as I said, that is without a servo. Then as I drove off, I realised he forgot to test the horn or wipers!
Richard