MOT test and Hand Break

I read a bit more (should have done it first, sorry) and see that if there is a service brake with a split system the park brake can have a reduced effectiveness.

There's also a very interesting little note at the bottom of the "Brake Efficiency Table" stating that "16% parking brake efficiency equates to a vehicle holding on a gradient of 1 in 6.25". Is that an acknowledgement that, at least for the 16% test, it is permissible to conduct a static holding test on a 16% minimum grade?

By definition, if a vehicle has only one primary braking circuit then the "handbrake" is classed as a secondary system working on 2 wheels only, and must meet a higher brake force (as a percentage of the vehicle's mass) than if the vehicle had a dual-circuit braking system.

Quite. Someone, somewhere, decided that the "handbrake" should be tested in a similar fashion to the main braking system(s). That's the test that is stipulated by VOSA in the UK, so that's the test that we, as testers, have to conduct. Anything else and we leave ourselves wide open to penalisation (and possible loss of testing authorisation) by VOSA. To be honest, I have no issue with that on a vehicle where the "handbrake" is the secondary system, i.e. single-circuit service brakes. As I already said, it ought to work correctly or there is some sort of fault. Soft engine and gearbox mountings are a favourite.

Sorry, don't get you there. The efficiency, as I understand it, is the brake force applied relative to the vehicle's weight. I tested my own 110 yesterday, it has a brake test weight of (I think, from memory) 2210kg and it produced over 1900kg brake force on the rollers, which I feel is quite good for the type. Interesting point, the rear drums produced slightly higher braking force than the front 4-pot vented disc setup!! Now that surprised me, I must admit.

Parking brake balance is pretty much irrelevant anyway, as long as the required "efficiency" total is met there's no problem. (Unless, of course, one side is down due to an obvious fluid leak onto the brakes) Badger.

On or around Wed, 25 Oct 2006 20:20:33 +0100, Dougal enlightened us thusly:

it's expressed in terms of braking force as a percentage of vehicle (or axle, actually, I think) weight.

On or around Wed, 25 Oct 2006 20:42:17 +0100, "Badger" enlightened us thusly:

they're bloody good brakes, those drums.

mind, have you got EBC pads on the front? they tend to take a bit of heat to work really well, IME, although they work much better when hot, and don't seem to glaze like some pads one could mention.

On or around Wed, 25 Oct 2006 19:57:57 +0100, "Oily" enlightened us thusly:

well, yeah, that I suppose. I had in mind the brake failure warning thing you tend to get between the 2 lines on some systems... somehow, linking 2 supposedly independant systems doesn't make sense.

"Austin Shackles" wrote :-

Both fluid systems are separate and at the same pressure, being fed from two separate compartments of the master cylinder of the same diameter and if the pressure falls in one system as in a burst pipe, the greater pressure of the other system forces the shuttle valve towards the leaking system in the 'pressure differential valve' and blocks it so there are no further leaks and also lifts a switch connected to a warning lamp and after one more stroke of the master cylinder, restores the pedal position so you can stop, albeit with less braking efficiency. The warning lamp then stays lit until repairs are effected and the shuttle in the valve is returned to the central position (unless of course the bulb is popped or a million other things go wrong that could).

Martin

No mate, std landrover genuine parts vented discs and pads. Wouldn't touch brakes beginning with "B" if you paid me!! Badger.

I'd rather assumed that they'd gone into museums. I live in a state where annual vehicle testing is not done, only requirement for a roadworthy test is upon sale of the vehicle as a road-going vehicle. So my 38 year old Series never sees the inside of a commercial garage. There are pro's & con's to Queensland's laws, we do have a few 'bombs' around but mostly the police roadside checks pick 'em up before someone gets killed by them.

You make a sound argument for their use, I must admit.

Sounds like an urban myth to me - despite my best efforts (deliberately with old wrecks just to see what would happen) I've never managed to have a catastrophic failure by engaging park at speed. Engaging reverse whilst traveling forwards at speed does however cause a whole range of interesting effects and could well tear an engine and gearbox off it's mounts (and is quite a good way to spit bits of driveshaft all over the road).

Assuming that's the same "B" that supply sub-standard brake parts here I'll quite agree with you.

On or around Thu, 26 Oct 2006 00:53:06 +0100, "Badger" enlightened us thusly:

EBC doesn't begin with B... and come to that, nor did the pads that got glazed. I think they Delphi ones.

My main objection to standard parts is the price of same, and for a lot of things, the price difference is not reflected in the quality. This may not apply to brakes, I don't know.

Paddock, for example, had CV joints for 25 quid a bit back. Now, these are undoubtedly not as good as genuine LR ones, but then again, at that price, and bearing in mind they're not hard to fit, you could replace 'em every 2 years.

consider, from Beamends's list:

FTC1332 Front Driveshaft (Inc CV Joint) - RH 33-Spline

3 options: Britprat at 94 quid, Spicer at 199.63, Genuine at 446.50, all including the chancellor's cut. I daresay Britprat ones aren't as good, but I doubt frankly that the genuine ones are at least 4 times as good, and it's quite possible that the Spicer ones are the same as the genuine ones but without the LR badge on.

On or around Wed, 25 Oct 2006 23:43:11 +0100, "Oily" enlightened us thusly:

yes, I know how it works in theory. I've also seen such things as engine oil pressure switches that leak oil out of the top...

On or around Thu, 26 Oct 2006 15:22:05 +1300, EMB enlightened us thusly:

Way I was told it, they were testing the box to make sure that it didn't break when idiots did things like engaging park on the move. It's possible that it was shifting to reverse that removed the engine, mind.

Austin, I was referring to the pads that "glaze like some I could mention", not the EBC's. Badger.

I assume they are the B?????x ones - summat like Bollox

On or around Thu, 26 Oct 2006 10:40:24 +0100, "Badger" enlightened us thusly:

I know you were, and personally, I don't buy cheap-brand pads such as first line and the like - however, I've been disappointed with the quality of the supposedly-good lockheed/delphi ones, which used to be OK.

I had genuine pads on the 110 ISTR, mainly 'cos no-one seemed to list the ones for those calipers (early 110) at the time I wanted to buy 'em, and they performed well.

"Austin Shackles" wrote

Doh... I cud 'ave saved me breath. ;-)

I've also seen such things as engine

Yebbut, them's Fords and OT. ;-)

Martin