M.O.T. Problem

[verbero]

Hi all,
I'm new to the site, and been P---ed off by a M.O.T inspector.
My P 39 Landy has a Transmission Brake and has been failed twice by this nerd for imbalance on a rolling road, against the manual and peoples advice.How can a single drum cause imbalance?????
I have searched high and low for some info on P38 Parking Brake testing on VOSA's site and many others, and have only come up with " use a decelerometer" which the M.O.T place say, we don't need it as our rolling road is 4x4 "friendly". O.K for foot brake but not for Parking Brake I think.
Any advice may help now, cos Iv'e taken this problem up with VOSA and it may hurt unless I can come up with some proof.
Thanks in advance,
verbero.

 

[the hooded claw]

Firstly by "Transmission" brake I assume you mean Handbrake.... So.... An "Imbalance" is when 1 side of the car is not working "To the same strength" as the other .....

i.e. you pull yer handbrake on & it WORKS ...BUT.... its only working on 1 rear wheel NOT BOTH ....There-by causing an "Imbalance"

It would be relatively simple job to check the cables & Grease as necessary & replace BOTH rear brake shoes & drums.... (Probs from a Scrapper, Drums that is, Shoes are rwadily available NEW for a few pounds)......

It is not a hard job & could be done in 20 Minutes or so ......


Read This ........................>>>>>>>>>>>>>>>>http://www.ukmot.com/3-7.asp#Text_top

 

[The Mad Hat Man]

I think the OP is making the point (and I may well be wrong here) that the handbrake works on the back of the T-box - not on the wheels - so if it locks the rear prop, how can it affect one side more than the other?

 

[the hooded claw]

I think the OP is making the point (and I may well be wrong here) that the handbrake works on the back of the T-box - not on the wheels - so if it locks the rear prop, how can it affect one side more than the other?

MHM.......... Yeah that wot I deduced as well ..BUT I read it as "The Tester had called an "Imbalance" ... NOT between each rear wheels but between Front & Back .....

Because its a "Dual" system the % Imbalance between Front & back "SHOULD NOT" Exceed 25%....(According to that link) ....

Sorry I didn't make myself really plain in my first reply did I ...The OP doesn't say what year his P38 is ......I Have seen OLDER p38 with "Shoes & Drums" (only 2 mind, & they were "adjusted" fer "Off road") & didn't have Tranny Brake discs.............

 

[The Mad Hat Man]

MHM.......... Yeah that wot I deduced as well ..BUT I read it as "The Tester had called an "Imbalance" ... NOT between each rear wheels but between Front & Back .....
....

erm - maybe I am being very obtuse here - but how does a handbrake work on the front?

if the handbrake is applied then there will be no braking on the front, will it?

 

[Sean]

shirley it should also have failed for an imbalance of the foot brake as well ?

 

[the hooded claw]

erm - maybe I am being very obtuse here - but how does a handbrake work on the front?

if the handbrake is applied then there will be no braking on the front, will it?

Testers have to calculate the % braking force on the entire Vehicle each corner divided Ect ect X 100 I would assume the tester is saying its Failed due to insufficient Braking force % .. & hes blaming the wheel with the lowest reading ...

Its HARD to explain ...MHM ...Clicky that linky & have a read ... That much easier than me trying (Badly) to explain it !!

 

[The Mad Hat Man]

nar - carnt be arsed . The OP will get it sorted - mite even tell us how it gets resolved .

 

[paul_c]

Testers have to calculate the % braking force on the entire Vehicle each corner divided Ect ect X 100 I would assume the tester is saying its Failed due to insufficient Braking force % .. & hes blaming the wheel with the lowest reading ...

Its HARD to explain ...MHM ...Clicky that linky & have a read ... That much easier than me trying (Badly) to explain it !!

I'm not fully convinced you know how the handbrake works on a Land Rover.

There is a section in the MoT manual which deals with transmission brakes, politely advise the MoT tester to read it up. Its strange you've failed to make this clear to both the tester and VOSA. I'd suggest a more sympathetic MoT garage.

If its the only thing its failed on then there is the appeals process.

 

[verbero]

Thanks for the funny remarks, they ( the M.O.T. station ) were checking a rear axle on a rolling road with the propshaft locked ( as the tranny brake was on ) so all it was doing was sending one wheel clockwise but due to the diff, the other wanted to turn anti clockwise hense showing one spinning free and the other one scrubbing and showing a reading and screwing my diff up cos there is no shoes on the rears.
I have since been on to VOSA and they have told me they are wrong to do this, I will complete a VT 17 and get VOSA to come down to the M.O.T. station, do the test with the tester and show him how it's done on a vehicle like my 2.5 DSE.
Also the station get "punishment points" and a reprimand and a retest of the tester himself.
All the best.

 

[paul_c]

Good news!

 

[kooky_guy]

That tester must be a right pillock. I thought they ought to at least have some grasp of mechanics in order to become a tester!

 

[wammers]

Deary, deary me and this prat is actually trusted to work on peoples cars. Things like this make us old timers shudder. Another NVQ generated technician no doubt. Totally unbelievable. What a bloody idiot.

 

[mad mechanic]

Deary, deary me and this prat is actually trusted to work on peoples cars. Things like this make us old timers shudder. Another NVQ generated technician no doubt. Totally unbelievable. What a bloody idiot.

we have a couple at our place, pair of dumb ass pillocks if ever there was any. makes me seeth when they talk the talk but then have no idea how to walk the walk.

 

[craig_midz]

i had an mot tester wantin to put my range rover on a rolling road an i said sure as long as you understand if the diff or transfer box blows up that they will be replacing it an as soon as i said that they refused to test it so i went to garage next door an he was an old fella not a college kid an ive never had probs an use him regular now

 

[paul_c]

i had an mot tester wantin to put my range rover on a rolling road an i said sure as long as you understand if the diff or transfer box blows up that they will be replacing it an as soon as i said that they refused to test it so i went to garage next door an he was an old fella not a college kid an ive never had probs an use him regular now

I don't think there's any actual danger of the transfer box or diffs blowing up!!!

Its more for viscous couplings, LSDs and suchlike where the problems lie, and there's no actual danger to the car in this case, but what would happen is when one wheel is driven, the other would turn too and the car would either move forwards (ie the rollers would 'drive' it almost off the rolling road) or either tyre would lock or spin against the roller. For a vicous centre diff, the wheels not on the rollers would 'drive' the car (almost) off.

Unsure if there's actually any danger of damage to a viscous centre diff, surely it would simply work as designed and apply drive to the other axle?

The real vehicle damage scenario is historically due to Daf 33s which used belt drive variomatic transmission which was never designed to cope with one wheel spinning and the other stopped (it coped with the slight variations in wheel speed during cornering, but not big variations).

Basically, it means the machine can't make meaningful brake readings.

 

[Pikey]

correct method for permanent 4wd is a tappely ?? meter. or decellerometer as they are known.

 

[wammers]

correct method for permanent 4wd is a tappely ?? meter. or decellerometer as they are known.

Yep Tapley meter. I remember testing a 42 seater Leyland coach. Apprentice sat in isle mid point with Tapley meter when i slapped on from 30mph he and Tapley meter ended up at my feet. It passed.

 

[Trewey]

You can't use a Tapley meter to test the hand / transmission brake!

 

[wammers]

You can't use a Tapley meter to test the hand / transmission brake!

Of course you can. What do you think brake systems were tested with before rollings roads?