MX5 MK 3 braking force... post MOT question

[Vaud]

So I got the attached with my MOT (full pass) and not having looked at one in detail before...

Is such an imbalance in braking normal (left vs right)?



Cheers...

[Vaud]

Bump...

[ChilliWhizz]

Interesting... Can't answer the question but do you get a noticeable 'pull' to the right under braking?

[Vaud]

ChilliWhizz said:

Interesting... Can't answer the question but do you get a noticeable 'pull' to the right under braking?

Not noticeable. Identical new (Toyo) tyres all round as well - so no differential in grip.

[Spangles]

The surface of the left roller is probably worn and locking before the right.

Dunno why the handbrake readings are so different from the service brake though.

[ChilliWhizz]

Reason for rejection (MOY failure)....

d.
the out-of-balance of the brakes on the steered road wheels is greater than 25% (30% for Class 5 vehicles) at any time whilst brake effort is increased gradually (see Method of Calculating Brakes Out-of-Balance in Section 3.8)

Taken from here...
http://www.motuk.co.uk/manual_370.htm

I'd query it with the tester.....

Chilli.

[Spangles]

ChilliWhizz said:

Reason for rejection (MOY failure)....

d.
the out-of-balance of the brakes on the steered road wheels is greater than 25% (30% for Class 5 vehicles) at any time whilst brake effort is increased gradually (see Method of Calculating Brakes Out-of-Balance in Section 3.8)

Taken from here...
http://www.motuk.co.uk/manual_370.htm

I'd query it with the tester.....

Chilli.

'Brake imbalance across an axle is to be disregarded if the lower recorded effort is as a result of a locked wheel.'

[ChilliWhizz]

So quite possibly a worn roller and a lock-up... I'd definitely call the tester and ask if it was the case, just to put my mind/curiosity to rest..

[TooMany2cvs]

ChilliWhizz said:

Reason for rejection (MOY failure)....

d.
the out-of-balance of the brakes on the steered road wheels is greater than 25% (30% for Class 5 vehicles) at any time whilst brake effort is increased gradually (see Method of Calculating Brakes Out-of-Balance in Section 3.8)

Taken from here...
http://www.motuk.co.uk/manual_370.htm

I'd query it with the tester.....

But the maximum imbalance recorded is just 7%, well within 25%. And it passed.

[Spangles]

ChilliWhizz said:

So quite possibly a worn roller and a lock-up... I'd definitely call the tester and ask if it was the case, just to put my mind/curiosity to rest..

All 4 wheels locked on both tests, it says it on the bit of paper.

[Vaud]

TooMany2cvs said:

But the maximum imbalance recorded is just 7%, well within 25%. And it passed.

Indeed -- I'm happy that it passed... as per my original question, I'm curious if it is normal or something I should be keeping an eye on as a potentially developing problem.

[Byker28i]

I'd take a look at them just in case one side is dragging

[ChilliWhizz]

Well I'm fooked, the image I can (barely) see in the opening post is very blurred, however I've just double clicked on it and the resulting image on thumbsnap clearly has imbalance, efficiency, and lock up details on it...

Lesson learnt for the future methinks..

[Vaud]

ChilliWhizz said:

Well I'm fooked, the image I can (barely) see in the opening post is very blurred, however I've just double clicked on it and the resulting image on thumbsnap clearly has imbalance, efficiency, and lock up details on it...

Lesson learnt for the future methinks..

Sorry, yes, I used a thumbnail upload...

[ChilliWhizz]

My bad, I should have known...

[graham22]

Could it be something as simple as wet tyres on one side of the car causing the earlier lock-out - puddle outside/something spilt on the floor?