Mot Due

[GTVGEOFF]

I seem to remember reading (I have searched but can't find it) that some MOT stations do not have the correct rolling road/brake test equipment, and if not damage can occur with gearbox or maybe diff (GS).
Can someone refresh my memory to what question I should ask the examiner. Thanks in advance.
Regards Geoff

 

[Oneball]

It’s the LSD that may have an issue. You want to ask if they will test the braking efficiency using a Tapley meter rather than rollers.

 

[philw696]

As an ex MOT tester myself what Tim says is spot on.

 

[GTVGEOFF]

Thanks to you both. Now to admit I don't know what a Tapley is, mind explaining.

 

[philw696]

The Tapley meter goes on the passenger floor and records the efficiency of the brakes at a slow speed and the same for the handbrake.
It's a deaccelerometer.

 

[GTVGEOFF]

Thanks for that Phil, I would never have guessed that.
I can't imagine many of the smaller garages will have one of those, and even if they do it means somebody is going to be out on the road in y car

 

[CatmanV2]

Thanks for that Phil, I would never have guessed that.
I can't imagine many of the smaller garages will have one of those, and even if they do it means somebody is going to be out on the road in y car

I think all MOT stations have to have one, and I don't think they need to take it very far at all (i.e. the car park is sufficient)

As ever, I stand to be corrected

C

 

[Zep]

My local small garage have one, not sure if it is an actual requirement, but I haven’t been to one that hasn’t yet.

 

[CatmanV2]

My local small garage have one, not sure if it is an actual requirement, but I haven’t been to one that hasn’t yet.

And they are pretty simple, I understand. Basically a pendulum?

C

 

[Zep]

And they are pretty simple, I understand. Basically a pendulum?

C

Older ones yes. You can also get digital ones.

 

[philw696]

It's a requirement that the testing station has one and it has to be calibrated.
The original Tapley is a beautiful tool.
You don't need to go far or speed to get the reading and no risk of damaging anything on the car.

 

[Scaf]

How would tapley meter work with the electronic handbrake which I didn’t think worked once you are moving.

 

[philw696]

How would tapley meter work with the electronic handbrake which I didn’t think worked once you are moving.

I used to just do a hold test.
I wonder if there is a special notice today with so many epb equipped vehicles.
I haven't tested since 2014.

 

[Oneball]

How would tapley meter work with the electronic handbrake which I didn’t think worked once you are moving.

Don’t know about MOT but construction and use regs still require 2 separate braking systems for all vehicles (including bicycles). So the EPB should operate while moving.

 

[Scaf]

Don’t know about MOT but construction and use regs still require 2 separate braking systems for all vehicles (including bicycles). So the EPB should operate while moving.

For some reason I thought they didnt work once you got you got going,

Can you test that for me in one of your cars tomorrow and let us know

 

[Oneball]

For some reason I thought they didnt work once you got you got going,

Can you test that for me in one of your cars tomorrow and let us know

 

[Scaf]

That’s pretty conclusive, although I would not try that with the ever so fragile EPB in a Granturismo

 

[Zep]

Not sure if you pulled the leaver on a GTS that it would brake all 4 wheels like a Golf.

There would probably be a clonk and your wheel would overtake you.

 

[TimR]

Perhaps I missed something but this has been discussed a number of times...
...the issue of LSD damage will likely only arise when two things occur at once..
.If the tester cannot get a sufficient reading when testing the brakes on the rollers ( it’s a nominal threshold I understand- so not a crazy hard test ) they are allowed/ might feel that they can get a reading if they brake the wheels independently ( ie, lock one wheel whilst rotating the other side of the axle ).
To my way of thinking; if the brakes are in good condition and working as they should, it’s not that likely this will be required by the tester..Even if it is, it’s not a given that the LSD will be damaged y independently testing wheels either...
Or did I not understand that right...?

 

[Zep]

Perhaps I missed something but this has been discussed a number of times...
...the issue of LSD damage will likely only arise when two things occur at once..
.If the tester cannot get a sufficient reading when testing the brakes on the rollers ( it’s a nominal threshold I understand- so not a crazy hard test ) they are allowed/ might feel that they can get a reading if they brake the wheels independently ( ie, lock one wheel whilst rotating the other side of the axle ).
To my way of thinking; if the brakes are in good condition and working as they should, it’s not that likely this will be required by the tester..Even if it is, it’s not a given that the LSD will be damaged y independently testing wheels either...
Or did I not understand that right...?

It is the turning the wheels independently that does the damage. As it is a plate type LSD, turning the wheels independently will always wear the friction material on the plates. So for me it’s a no brainer, don’t take the risk.