Brake tolerance in MOT test - Tony Gales
My P reg Ford KA has just failed it's MOT because the front brake discs are corroded and worn. I was shown the discs with the car on the ramp and there is evidence of slightly uneven wear but no real ridge on the disc.

Kwik fit immediately after the test said that the brakes did not need replacing for at least 3000 miles.

Is there any specification for brake wear in the MOT test? Is it worth appealing?


Tony Gales
Re: Brake tolerance in MOT test - John Slaughter
You don't quote a mileage, but the cars is probably 4 years old. Modern non-asbestos pads wear discs much more than the old asbestos variety, and replacing the discs at the same time as changing the pads is common. There is a good chance that the discs have been worm overall, and reduced in thickness below the manufacturers minimum limit, even if they are not scored. This appears to be their reason for failing the car. The good news is that as discs are changed more often these days, they have got cheaper. Although kwik fit say there is 3000 miles left it's not much and it's false economy to fit new pads to worn discs - when you come change the discs you can't reuse the worn pads or they'll immediately start to wear the discs unevenly!


Re: Brake tolerance in MOT test - Tristan Chaize
You say the car failed because the discs were "corroded and worn". You then say there was evidence of "slightly uneven wear but no real ridge on the disc". Are you saying the discs were NOT corroded? Also I don't know what you mean by "slightly uneven wear". Did the brake pedal move up and down as you braked? I think that the MOT does not test for thickness, or even uneven wear. Rusting yes. Did it fail the retardation test. ie did the dials show uneven or insufficient braking?
As far as Kwick Fit is concerned, they are useless. The surprise is that they didn't try and sell you new discs even when you didn't need them. Perhaps they had none avaiable. That is the most likely explanation.
I think you should get a new MOT done at a different testing station before even considering an appeal. Talk to the guy. Be friendly. Don't use an MOT station that make you wait in a "customer waiting room". Use a small garage that allow you in. Get a good look at the discs. Then decide.
If you do want to appeal, get a second opinion from the AA or RAC. They at least will be believable. If you appeal, it will cost you a lot of time and hassle. You must be 100% sure you are right before you appeal.
Re: Brake tolerance in MOT test - Tony Gales
Thanks for the replies.

I looked at the car on the ramp; I don't know about it's retardation test.

The pads certainly have sufficient thickness, its the discs that are the failure point. They are ceratinly not rusty at all, there is some minor pitting on the outside half inch of the discs circumferance. I went to Kwik FIt because I was sure that they would recommend replacement if there was any doubt, yet they didn't.

What I need to know is - is there any written specification for the discs in the test?

Thanks again

T Gales
Re: Brake tolerance in MOT test - E Tunmore
You should look at this link. It provides in-depth info on what the MOT test actually is:



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