GT6 rear brakes

[npanne]

Hi all,

Can anyone confirm, or does anyone have a clear picture showing how the adjuster mechanism fits to the late GT6 MkIII (non-roto)?
I'm building my back axle up from component parts, and whilst I have everything, I am having to piece it together using parts diagrams etc - which has got me 95% of the way, but there's just one thing that's not clear - and that is which way round the adjusters (the toothed wheel) fit into the cylinders - they're "sided", and I have both a left and a right, I just don't know which is which.

This was the best picture the internet threw up :


And I found a couple on an old thread on here:
Sorry , link no longer available

But neither show the adjuster clearly enough

[mpbarrett]

As the hand brake is operated the arm should act on the wheel and the adjuster acting on the brake shoe move out wards. Also you need the small H shaped spacer on the  lever on the left hand side of the cylinder otherwise the auto adjustment will not  work correctly.
I had a steep learning curve with the brakes my Gt6  to get the auto adjustment working correctly.
Mike

[RobPearce]

When I first took my old 2500S for an MOT it failed on rear brakes, because the self-adjuster had been assembled backwards.

When I MOT'd the TR7, I found the same fault for the same reason.

When I dismantled the Sprint's rear axle I discovered it also had the adjuster wrong.

Unfortunately all of those are the "other" type of self-adjuster, where the motion of the wheel cylinder does the work, rather than the one you have, where it's the handbrake that does it. I have owned one car with that setup - the 1850 Dolomite - but as I recall I never had any trouble with the brake adjuster on that.

I'm fairly sure, though, that it needs to go the logical way round. That is to say, pulling the handbrake should turn the adjuster. When correctly adjusted, the shoes don't back off far enough for the lever to slip onto the next ratchet. What this means is that the long arm across the top needs to be "primed to work" when the handbrake is released, which is with the lever close to the backplate.. In other words, the teeth of the adjuster should be such that the steep edge points to the backplate on the side where the lever is:

                    Lever
                ====
       /|    /|          ||
      / |   / |          ||
     /  |  /  |          ||   Backplate
    /   | /   |          ||
   /    |/    |          ||

[npanne]

Thanks everyone - that makes perfect sense.

[RedRooster]

I never knew that, bet mine are installed the wrong way then.
RR

[GT6 M]

Little advice which  i found oot the hard way,
maybe of some intrest to ye Neil

cos the brakes  self adjust, they tek up wear in the shoes, AND the drum.
when there wear int drum, the shoes sit ina groove,
this groove wont let the shoes come off the drum farr enough for the drum to come of the hub,

follow so farr !!

so I drill a bigg hole in edge of drum, so could get at the adjuster,
lift the lever up, and turn the adjuster backwards
so clearing the  groove int drum, so drum can come off.

bit like a manual adjuster if the drums have a groove inem
ye gotta turn the adjuster back, so brakes are free.

M

[npanne]

Good point - thanks.

[npanne]

While I'm on the topic of brakes - a couple more questions.

Firstly - the flexi hoses - I've just received a set of new hoses to fit - but do the longer ones go on the front or the rear? I'd guess at front, due to the greater range of movement, but does anyone know for sure?

Secondly - as I've replaced various nuts and bolts, I've applied liberal smears of copper slip to aid future disassembly - but the things that were truly impossible to undo were the brake line unions - is there anything wrong with putting some copper slip on these as I replace them, provided it only goes on the thread and doesn't get into the system?

[GT6 M]

nothing wrong at all,  but even better if ye can get S4 stainless,ns

M

[markcro]

A simple way is to look at the teeth on the wheel. The arm acts as a racket. So when it acts on the wheel it should grip the flat side of the teeth to adjust the adjustor outwards (push the shoes against the drum). And then when you release the handbrake the arm should slide back over the sloped side of the teeth. It acts like a racket- it only adjusts the shoes in one direction. i.e. to tighten them.

[Paudman]

Quoted from RedRooster

I never knew that, bet mine are installed the wrong way then.
RR

Mine were, they used to loosen after every drive and had to be retightened until I caught on.

[npanne]

Thanks chaps - I'd figured out the ratchet mechanism, but couldn't be sure whether it was acting on handbrake on or handbrake off - the wear in the arm was ambiguous, so I suspect it had been fitted backwards at some point.

All work has stopped now whilst the garage comes down (to be rebuilt eight feet to the right - I kid you not) - clearing everything out has made me realise how much space I'd have if I kept it clear - time to be ruthless with a lot of those "saving just in case" parts - particularly the bonnets...

[Marc F]

Tell me about it - I still have two bonnets (Spit Mk3 and GT6 mk2) plus a NOS bonnet top panel. Why oh why...

[RedRooster]

Going to check mine at the weekend as the hand brake isn't the best.

[RedRooster]

Well i wasn't expecting to find this, looks like when i built the car 20 years ago i fitted non adjusting cylinders for some reason.

Do i have to change anything else apart from the cylinders?

[RedRooster]

Looks like the self adjusting ones are NLA from Canleys & JP anyway (

[Richard B]

I think they were fitted to the Triumph 1500/1850? Doubt if there's many of them in the breakers either.

[Clive]

I got some used adjusters from Wins......
They are hard to find now.

[RedRooster]

Oh well that probably explains why i have the manual ones then.

Need to try & get the hand brake better adjusted as it doesn't hold the car on steep hills.

[Clive]

Any way of modifying the backplate so you could fit manual adjusters? That would be ideal.

[RedRooster]

I have manual adjusters on the bottom.

[Clive]

Then the shoes should adjust up and work well (enough)
There are a few workarounds to make the handbrake work "better", the easiest is to extend the levers.

That is, assuming the handbrake compensator is adjusted correctly and all else is as it should be.

[RedRooster]

Hi Clive,
adjusted the compensator as the first cable was a bit stretched, i also have the hand brake extenders on the drums, if it doesn't work better now i'll put a brick in the glove compartment.
RR

[RobPearce]

First cable stretched isn't usually the problem. The intermediate lever needs to be some way behind its mid-point with the handbrake released - over-tightening / shortening the front cable leaves it in front, where it no longer works right.

[Dogsbody47uk]

Quoted from RobPearce

First cable stretched isn't usually the problem. The intermediate lever needs to be some way behind its mid-point with the handbrake released - over-tightening / shortening the front cable leaves it in front, where it no longer works right.

15 degrees behind on herald or Vitesse. Probably the same on Spit or GT6?