Brakes And Your Mot How It Works

[ormi]

right mot standards for brakes how it works.you bring the car in and over to the brake tester then you enter the cars details reg and last 6 digets of the chassis number

you then check the details it brings up ie make,model ,fuel type etc you then print off a vt40 which contains the vehicle weight ie is200 1500kg so now on to the brake test

you then enter the vehicle weight reg make and model now on to the test its self

on the rolling brake tester you take 8 measurements.............

both fronts

front left

front right

both rear

left rear

right rear

all of the above are foot brake

rear left(hand brake)

rear right(handbrake)

all results are recorded by the brake tester(mot person has no controle over this)

if the machine calculates all the figures and says its a pass then its a pass no questions the tester can't over ride the computer ie 25% imbalance passes

even if i think its wrong and the brakes could do with work its a pass and advise

what you can fail brakes for

excessive pitting(not corrosion)

excessive wear(thats a grey area though as your not allowed to messure the disks on a mot)

excessive scoring

no reserve travel in hand brake

general faults with the lever

wont go in to the rest as it will take me all night but my point is the computer decides if the brake readings are a pass or a fail not the tester so theirs no need to argue about how bad it is for a car to have a 25%imbalance and how it should ba a fail coz its not the computers word is final....................

[Gord]

And 4x4

[ormi]

And 4x4

depending on what one...rav4 ok landcruiser ok to use rolling brake tester

audi tt no golf 4x4 no etc then you'd go to the decelorometer(cant spell to save my self) in which case you don't know what the imbalance is you just take two readings brake(foot) and handbrake.and enter the readings(you can't enter the readings if your using the rolling brake tester) in to the computer and it tells you if its a pass or fail.

[Gord]

Mine was taken on test drive to see if brakes ok for MOT :D Audi S4 Avant Quattro

[Parthiban]

Cheers for clearing that up mate, that's exactly what I wanted to know. However, clearly a car won't get through on a very high percentage, but at around 15% it would still pass (as that other member said, but with an advisory)

I still think that's too high, wonder how many cars would be off the road if they dropped the tolerance to 5%.........

[Rob's Lexx]

i always thought that any cars fitted with LSD's had to be tested on the roads using a decelerometer?? I know mine always is.....

[MacRS200]

Agree with ^^^^^^^^

Saw them try the Tezza on the rollers once

[Steviewevie]

i always thought that any cars fitted with LSD's had to be tested on the roads using a decelerometer?? I know mine always is.....

How do they know if you've got an LSD though (assuming you haven't taken it to Lexus), since it's not easy to tell ? Do they work it out from the VIN or something ? Just that I haven't been asked.

[Gareth Rose]

I've had 2 MOTs on my sport, and I don't think they tried it on the road. But the guy I use has really old equipment with big analogue gauges to display the brake force. Don't know if its any different with newer equipment.

Gareth

[shak]

i always thought that any cars fitted with LSD's had to be tested on the roads using a decelerometer?? I know mine always is.....

How do they know if you've got an LSD though (assuming you haven't taken it to Lexus), since it's not easy to tell ? Do they work it out from the VIN or something ? Just that I haven't been asked.

When the back end is jacked and you spin one of the wheels forward on an LSD, the opposite wheel will turn in the same direction, on a normal diff the opposite wheel wheel spin backwards.

From there you know what brake test to do, thats how I usually check anyway.

[ormi]

is200 with lsd is ok on the rolling road it depends on the type of diff and how much slippage/speed the wheel is allowed to do before the diff lock's the other wheel.

to Parthiban if it was lowered to 5%, 95% of cars would be off the road!!!!

[ormi]

I've had 2 MOTs on my sport, and I don't think they tried it on the road. But the guy I use has really old equipment with big analogue gauges to display the brake force. Don't know if its any different with newer equipment.

Gareth

no its not diff mate just the same(brake rollers) exept you have to work things out with the gauge and your head newer equipment the computer does it all for you!!

[Parthiban]

to Parthiban if it was lowered to 5%, 95% of cars would be off the road!!!!

Maybe 10% then, but the end result sounds about right - more cars off the road means less traffic for the rest of us to drive around in :)

Seriously though, what level do most cars come in at when in their MOT? For example, if we put most of the IS200s on here through the test, what imbalance would be present?

[ormi]

most cars come in from 5% to 16% mate thats the norm and theirs nothing you can do as a tec coz if its not a fail people don't want them fixed same if they get a 25% imbalance if its not a fail they dont wanna know.

i've mot'd 4 is200 (members on here) on average the imbalance's were from around 7% to 15% although one was 20% the one that was at 20% i stripped and cleaned and got down to 5%(piston needed removed and cleaning)