MOT test and Hand Break

How is the hand break tested in other Countries. Here in Ireland, the last time I went, they drove the Range Rover and pulled it on. If the contraption they had installed on the floor registered the correct reading all was ok. If not it failed. No mention of the transmission and damage it might have caused.

I have to go for another test in the near future and I am seriously hoping they have changed the test methods.

Hugh

Reply to
Hugh Hogan
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The last f****it vehicle tester who applied a cardan shaft handbrake like that on one of my vehicles was unemployed shortly thereafter.

It is NOT an acceptable practice - I've seen the backing plate torn off the back of the gearbox after somebody tried this. The only safe methods of testing this type of handbrake are either statically by checking it will hold the vehicle on a slope of the required grade, or loading the brake by engaging first gear and GENTLY releasing the clutch to ensure that the vehicle does not move.

Reply to
EMB

You could start by nicely explaining the hazards with reference to the owner's manual (I think that there's something there).

There is this document on the website of the Irish Department of Transport (effectively the testers' manual)- no guarantee that this is the appropriate document but it looks right:

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You should look at Item 23 on page 32.

It doesn't make very comforting reading as they mention only a roller test (apply the parking brake slowly...) or if a roller test cannot be used a decelerometer test. Transmission brakes are acknowledged but if the roller test cannot be used there is no official 'get out' to save your driveline.

Reply to
Dougal

"Dougal" wrote in message news:zdCdnRy-0c snipped-for-privacy@eclipse.net.uk...

Bottom line for a landrover in the UK (Areas covered by VOSA rules):- You basically have 2 choices;

  1. Roller brake test if vehicle is of a design that allows, i.e. not viscous centre coupling;
2..Decelerometer test.

The ONLY (legal) way your vehicle will legally pass an MOT is if the handbrake is tested in accordance with the MOT rules, nothing else. On series and pre-viscous centre diff motors, I tend to try the rollers but if any snatching occurs I stop. I always work out the brake force required for a "pass" regardless (16% for dual-circuit brake system types) and stop when (if!) I reach that figure. If a decelerometer test is required, again the handbrake is applied very slowly and only until the required force is indicated, no further. Personally, I strongly disagree with having to test landrover transmission handbrakes in this fashion, however, the handbrake has passed type-approval for the vehicle which means that it must be suitable/safe to be applied in an emergency if a total brake failure occurs, and there is no other procedure open to the tester within the limits of the tester's manual. Another point I would add - as long as there is no excessive free-play in drive members, diff, prop u/j's and splines, and the handbrake is operating correctly, then they don't snatch and judder and are therefore safe to test by either of the 2 above methods. From experience, there are only problems if there is a fault or wear somewhere. I still don't agree with it however, but there is no other way of (legally) getting an MOT pass. Before I was an MOT tester myself, my "local" tester would try to gently pull away with the parking brake applied, if it didn't move it passed. However, this isn't "legal" for VOSA, and if the vehicle subsequently has an issue requiring VOSA's involvement (post-R.T.A. investigation, appeal, etc etc) and they test it "correctly" and it fails, it's the tester that gets it in the neck big-style! (Unless he/she can prove that they tested it correctly and it was ok at the time of testing) I've been a witness at a VOSA investigation, and believe me when I say I wouldn't want to be the one getting investigated!! Badger.

Reply to
Badger

They still use Tapley meters on a 4wd in this day & age???

Reply to
Duracell Bunny

On or around Wed, 25 Oct 2006 10:22:56 +0100, "Badger" enlightened us thusly:

Hmmm. Ought to check the latest disco for driveline play... That exhibits lots of snatch and judder.

Reply to
Austin Shackles

"Badger" wrote

If the viscous coupling is not seized then I would say it's not going to do any harm because the rollers are only moving slowly and you would get your necessary reading, but if it *is* seized it would only push the motor off the rollers, not do any harm either, and you would know the viscous coupling

*is* knackered.

but if

I don't agree with this at all and wouldn't allow my handbrake to be tested this way, though I've no objection to the rollers which are a controlled speed.

type-approval

The vehicle should be parked on a steep incline, the handbrake applied whilst stationary, and the vehicle should remain stationary. The handbrake is a *parking* brake and should only be tested as such, the dual line braking system is fitted to deal with as a backup as I see it.

Martin

and there is no other

Reply to
Oily

I'll say again

If the rollers are modern enough to have a dedicated 4wd mode, then this will work for the front and rear axles as it allows the wheels to rotate in opposite directions whilst testing one at a time. However, some vehicle's traction control and abs systems will kick in and make the thing climb out of the rollers regardless. I still don't like applying the handbrake on a viscous motor whilst doing the front brake imbalance test, it's not doing the transmission any favours! Policy in the place I do my MOT's is :- 2wd, rollers. 4wd, tapley/bowmonk.

You may not agree, and for the record neither do I, BUT that's the rules and if you don't like it then you don't get your MOT test. By working out the minimum effort required for a pass and not exceeding it, I'm doing you a favour!! Another point to consider, the rollers will allow each wheel's speed to change independantly, giving rise to a lot of backlash induced snatching. The road doesn't - that actually helps to avoid snatch and clunking when applying the parking brake during a decelerometer test, which is also a controlled speed, 20mph and apply smoothly.

Not a valid and legal test, m'Lord. Sorry. Even if I agree with you, which I do, we are confined by the rules.

Yes, which is why the efficiency rating for a parking brake is 16% on a dual-circuit vehicle and (I think) 25% on a single-circuit. The theory is that with 2 service brake circuits the handbrake is no longer required to be the secondary brakig device, BUT having said that, it is still homologated as a device that *can* be used as an emergency brake. As an MOT tester and mechanic with a lot of years experience on landy's, I personally STRONGLY disagree with the methods for testing landrover parking (hand) brakes, but these are the rules and they are unlikely to change. There ought to be a "static pull test against the brake" for vehicles with dual-circuit brakes (much the same as the original motorcycle brake testers), BUT single-circuit landys (up to around earlyish SIII?) would still have to be roller or decel. tested, as the handbrake IS the secondary circuit! Now, if the parking/hand brake has been designed to function as the secondary system for emergency use, as it would have been by the manufacturer, and it's design hasn't really altered since (other than cable operation instead of rods), is it not reasonable to assume that it should work correctly either by roller or decelerometer testing? Is that not *why* we are testing the vehicle annualy in the first place, to sort out the badly maintained and unsafe vehicles? Badger.

Reply to
Badger

Indeed they do, Karen. As the vehicles have become more and more sophisticated with all their ABS, Active differentials, Traction Control, Electronic Brake Distribution etc etc, there are now a lot of vehicles that "chuck the teddy" if placed on rollers that do anything other than turn all

4 wheels at the same speed! Some will light up their dashboards like Blackpool Illuminations, some will attempt to "leave" the rollers. For this reason, we still use Tapley and Bowmonk type decelerometer testers. In all honesty, they are good, reliable and accurate devices. They also give the tester the oppertunity to assess the brakes whilst actually driving, possibly allowing a sensible tester a bit of leeway in deciding that something is actually ok???

Badger.

Reply to
Badger

But after such an 'Emergency' stop the vehicle does not have to be driveable. Slapping an auto into 'P'ark (if it will go) will meet that requirement, but is exceedingly unlikely to perform thereafter!

I have asked here in the North how they do it and was told on the rollers, quite simple, one wheel at a time reversing direction of axel pairs.

Another point I would add - as long as

Reply to
GbH

The "Park" facility on an auto IS NOT an emergency brake however, it is a safety device to prevent the vehicle moving and crushing a mechanic/owner/ innocent bystander should an internal hydraulic fault cause a gear to be engaged whilst the vehicle is being worked on with the engine running. Applying it whilst in motion is a sure-fire way to shear the operating pawl within the 'box, making it a one-shot system!

Doesn't work on a landrover though, the brake drum is at the output of the gearbox, on the rear propshaft. If the wheels are allowed to turn in opposite directions then the wheels will continue to rotate with NO brake force being registered as the parking brake is applied. A basic function of how a differential operates

Something else to consider, roughly on-topic, how many MOT testers bother to put the transfer box in neutral and autobox in Drive when doing the emissions testing? It's a well-known and well documented failure mode for the ZF4 autobox, revving the engine in P or N can cause premature wear of the input shaft oil sealing rings - closely followed by "A" clutch failure and loss of all drive!

Badger.

Reply to
Badger

On or around Wed, 25 Oct 2006 11:01:57 +0100, "Oily" enlightened us thusly:

The law says otherwise, though, I suspect. And there are credible failures of a dual-line system which can disable both lines.

Reply to
Austin Shackles

On or around Wed, 25 Oct 2006 12:00:43 +0100, "Badger" enlightened us thusly:

I recall hearing a possibly-apocryphal tale about testing the strength of the parking pawl in the Borg-Warner factory and inadvertently finding a very fast way of removing the engine and gearbox from a Ford.

Reply to
Austin Shackles

Does anybody remember when the MOT first started, and the tester used a full house brick standing on end. If it fell over when handbrake applied it passed.

Reply to
Spanner

In message , Badger writes

That's an interesting one. Don't think they've ever done that on my defender auto - or any of my other autos.

Does it apply to all auto boxes or just this particular one?

Reply to
hugh

It's valid and legal at this end of the world - on of the few MOT type things they've got right.

Reply to
EMB

Wish VOSA would take heed and ammend things this end, but somehow I doubt it! Badger.

Reply to
Badger

Just the ZF4 series, as far as I am aware. Used in various BMW's, Jaguars, Volvo's and Landrover products. Very well documented in the USofA, lots of issues with BMW's having 'box failures after smog-testing, just do a google and you'll find some more info on that. I've had the fault on one of my own boxes, and sure enough when I stripped it the steel piston-ring type seals had eaten 2 grooves into the stator shaft (support shaft for the stator part of the torque convertor) and the main "A" clutch had considerable wear, caused by the resulting pressure leak past the seals. Quick test, get the box and oil hot, place in neutral on flat surface, hand (sorry, parking!) brake off, rev to 3000 and if it tries to creep forwards then the seals are worn and "A" clutch failure is probably imminent. Don't hold at 3000 waiting for something to happen, just get there then straight back down. Badger.

Reply to
Badger

Yes, I was forgetting about the RULES ;-)

It's a good job most Landrover handbrakes are full of oil and gunge or your forehead would look like it had mumps. ;-)

Yep them goddam rules again. ;-)

I don't honestly think Landrover gave a s**t about an emergency backup when they designed the handbrake on the old series, or they had a funny sense of humour. Bloody lethal as a secondary brake if they are clean and kept adjusted.

Martin

Reply to
Oily

Poor maintenance?

Martin

Reply to
Oily

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