MOT and brakes

[Vernon]

I have just had an MOT test this morning and although my Traveller passed the test I was given a note of the figures from the brake test.
I forgot to ask what the figures mean so can someone tell me please?
They are :-

185 170
140 150
155 160

Do these figures indicate that the brakes need attention?

[simmitc]

Good news, it's always pleasant to get a "pass", and the more Moggies on the road, the better.

There will be three pairs of readings: Front brakes, rear brakes with pedal and rear brakes as handbrake. For each pair, there is a left hand wheel and and a right hand wheel reading. The figures represent an efficiency (I'm sure that somebody will be able to be more precise about what exactly). As long as the left and right are similar the car should stop in a straight line. As long as front is higher than rear (within reason) then the system is balanced; and as long as the handbrake works you won't roll away down hill.

Very low or very high readings can show seized off or seized on cylinders. Low can also show oil / grease contamination or worn /badly adjusted shoes. Leaks would (or shuold) be detected by pedal travel and visual inspection. If the brakes had needed attention, you wouldn't have got the MOT !

Just because it passed today, don't neglect the brakes for another year, keep them adjusted and clean as part of a regular service.

[Cam]

Well, I would assume that the two columns are the left and right, and the top row is the front service brake, the middle row the rear service brake and the last row the rear parking brake.

The formula used is (effortx100)/weight = efficiency. And if the car is pre-jan '68 then you need 40% efficiency to pass or if it's post jan '68 then you need 50% efficency to pass for the service brake and 25% for parking brake...

Presumably then these figures are the braking effort, but they don't seem to be in kg or lbs???

[bmcecosse]

Do they have a weight figure for Morris Minors ? A couple of years ago they used a Tapley meter to test my brakes because they had no weight figure - that's much easier to pass !!

[Kevin]

Well thats news to me as for as long as I have been back into Moggies (2nd time around over 10 years) I thought a brake testing rolling machine was an MOT requirment for all passenger vehicles for many years now.

[57traveller]

I vaguely remember, when the mot test was first introduced, I went with my father to have his then car (1937 Rover 14!) tested. There was no fancy test equipment and to check the efficiency of the brakes the car was driven at 30mph on a straight road by the examiner, with a house brick on the floor in front of the rear seats, it was layed on it's long edge across the car. If it fell over when the brakes were slammed on it was a pass. It could have been a slightly different set up but I remember a house brick being invloved somehow.

[Stig]

Now they couldn't do that these days 'cos there aren't enough straight stretches of 30mph road without speed bumps...

[57traveller]

Could be wrong Kevin, but I think a decelerometer is acceptable as long as it's approved, tested and calibrated at specified intervals.

[bigginger]

Is that the origin (given the chance that the brakes might fail) of the expression 'bricking it'?

[rayofleamington]

Now they couldn't do that these days 'cos there aren't enough straight stretches of 30mph road without speed bumps...

I've known a lot of garages actually road test the car before giving it back with an MOT - this is an added security as it's gives a better understanding of brake balance / wheel alignment etc.. than the tester machine.
Mind you - this was 10 years ago - they might not be allowed to do that anymore

[Cam]

Is that the origin (given the chance that the brakes might fail) of the expression 'bricking it'?

I thought that was a more polite way of saying 'passing bricks'.....