75ZT Community

hi chaps , i have a poor handbrake , even after fitting new uprated compensator , adjusting rear drums , with handbrake cable nut loose.. do you think i may have worn cables , due to the old compensator being bent... on the flat it just holds the car if you try and pull away , on a slope it is still poor.. Mot nxt sat cheers chaps...

Just had the same issue....re-inserted a 14mm spacer I had been using prior to the compensator mod....this is behind the nut on the handbrake lever....it then passed the MOT but whilst it feels fine...and did so with just the compensator...it still isn't as good as the handbrake on my OH's PT Cruiser!

There use to be lots of talk about stretched cables but when people measures the old ones against the new cables there was no difference in length, I wonder now that we all have fitted to new updated compensator that its now stronger than the cables causing them to give.

As Zeb says above fit a spacer on the handbrake to take up the extra slack, at least until you have your MOT.

This subject has resulted in several remedies which to a greater or lesser extent work admirably and since I fitted Arctic's excellent mod my h'brake is trouble free. However, as all the main components are either steel cables or steel bar I have doubts about the underlying causes being claimed as the reasons for the fall off in performance. I wonder if there are any metallurgical engineers out there who could mount a stress test on the original components? I would have thought the load required at the brake hand lever to produce torsion stress to stretch steel bars to that extent would be beyond the capability of the human arm!

On my auto, which I tend to not use the handbrake much, I fitted new discs/pads all round at about 85k miles.but not the
handbrake shoes.
But still the Handbrake was a bit naff. Fitted a modded Compensator and although better still not up the standard everyone makes out it should be ?.
After pulling off the discs I found the Drum surfaces were very badly corroded and heavily pitted, even after only about 30k miles..
I cleaned them up as best i could with lots of emery paper, and although not perfect this gave the greatest improvement.
Got another pair of rear discs/pads/shoes to go on when the weather improves .
Seems if the handbrake is not used often enough then the drum surface will suffer from crevice corrosion.
Always worth while pulling on the handbrake just before you are stationary to rub off any nasties ..
but The shoes must get a fair bit of rust embedded in the surface, this can't help ?.

C.

Certainly rust on the inside surfaces of the handbrake drums will reduce performance. And don't forget even after the mod is fitted, the adjustment inside the drums still needs to be spot on to make the system work OK. I don't think it's ever going to work really well, I'm afraid.

Cheers guys , my drums look good , gave them a good rub down , and they were in very good condtion. it has mintex shoes and pads fitted, and there seems plenty of meat still left on the shoes . going to do the spacer , and try that .. If that still dont sort it , then i will fit a new set of mintex shoes.. To be fair i dont use the handbrake loads its a auto , but i want it right... And after all , i have to please MR MOT MAN.... Never had a problem with a handbrake on any other car before... you start to doubt yourself iam doing something wrong...

Duncan wrote:Certainly rust on the inside surfaces of the handbrake drums will reduce performance. And don't forget even after the mod is fitted, the adjustment inside the drums still needs to be spot on to make the system work OK. I don't think it's ever going to work really well, I'm afraid.

I've always felt that this is the weak point of a separate Drum/ disc system . the discs will always get hot, this is always a good basic for rusty metal,( all of the rest of the disc is so) , but the pads will always rub this this away in use.
But not so the drums. these are applied usually stationary so never get the chance to rub anything off.
So this Rust will just get worse over time.
Always best to apply the handbrake moving every few days to give it a chance to do a bit of rubbing ,
I think I seen It recommended somewhere!!

Well that my opinion

Well after going for mot today , it passed... but still not happy with my handbrake, as it still dont fully lock the rear wheels...I had made it better , so going to fit some new shoes...

Mintex shoes part no MFR 522 don't work at all!!
The radius is too small and the shoe surface only touches a brand new disc at the center.
With a 1mm gap at either end of untouched surface.

The original shoes have twice the depth of meat on them

Jules wrote:Mintex shoes part no MFR 522 don't work at all!!
The radius is too small and the shoe surface only touches a brand new disc at the center.
With a 1mm gap at either end of untouched surface.

The original shoes have twice the depth of meat on them

That explains a lot. I had some mintex ones, and had really rubbish performance. Now I realise why.

I would have thought that even with the modification, once the rear pads wear down to a particular point they become poor?

Cheers

Mike

Further to my earlier post on this (blimey! Over a year ago! Where did that go?) Whilst I bow to superior knowledge and expertise of Steve (Arctic) I still think the steel bar, if it is actually steel as we know it, is way beyond the most Herculean efforts of my left arm to stretch or bend it given the length of lever from fulcrum. Not quite enough Moments in that equation! I did the compensator about 18 months ago and can confirm the whole process was an entire success. Whether I inadvertently did other things at the same time I am unsure, but it still works well at three clicks. It may help sufferers if I tell all of what I did.

While the handle was slackened off I took the discs off both wheels and adjusted the cog until there was a slight interference fit when it was replaced by pushing the disc on. The disc was removed again and the cog was then slackened off by one click. The other side was then done. The discs were then turned to ensure that there was no binding (just the slight 'brushing' sound) and everything replaced. The handle was re-adjusted to the recommended 25mm exposed thread and performance checked by rolling in Neutral (Auto box) and applying h'brake only - worked on 'three'. Still does and my mileage being low doesn't reflect h'brake wear as a car doing higher miles would have similar h'brake use. Incidentally, at tickover in 'D' (650/700 rpm according to rev counter) it needs 4 clicks to hold. Hope that helps.

It's not simply about moments. I can confirm I've seen a number of compensators, as have others, that have changed shape and length. I'm not a materials expert, but my guess is there's an element of creep. Essentially the moment you are applying is turning into a tension in the cables and compensator. While that tension doesn't appear to be able to bend the bar the compensator is made of, something is distorting it over time.

Yes Duncan, I agree. It's a phenomenon of sorts. When the brake is not applied, it's 'at rest' and under no load other than the tension caused by the locating shoe springs. It's difficult to see how that minimal level of load could produce such a dramatic distortion evident in so many units. That's why my original post asked about metallurgists. The only thing I can think of that might account for it is if the steel rod was lesser alloy of some sort. Given the reluctance of many car owners to properly maintain cars, and in the case of these cars that applies to many of those being able to afford them because of the relatively low acquisition costs but perhaps less able to manage maintenance as well, often the only adjustment made may be at the handle. Whatever, the compensator mod worked for me.

It is because the compensator bar, which is made from low ductile strength material, is under constant tension all the time that the handbrake is applied. This results, as Duncan says, in the material gradually unwinding around its pivot point and making it longer. Yanking on the handbrake in itself is not sufficient to distort it, it's the gradual creep over a period of time that does the damage. Once you have taken this out of the equation then all that remains is the adjustment of the shoes themselves as Jumper has posted above.

Jumper wrote:Yes Duncan, I agree. It's a phenomenon of sorts.

Well I wouldn't call it a phenomenon. Creep is a real behaviour of materials, but it's too long since I learned about it to be sure it could be that. Bernards explanation is the thing to go with.

When the brake is not applied, it's 'at rest' and under no load other than the tension caused by the locating shoe springs. It's difficult to see how that minimal level of load could produce such a dramatic distortion evident in so many units.

I'm sure it can't. But the majority of cars probably spend somewhere in the region of 22 out of 24 hours with the brake on, and probably pulled quite hard given how bad they can be.

That's why my original post asked about metallurgists. The only thing I can think of that might account for it is if the steel rod was lesser alloy of some sort.

It could still happen with a high grade steel, if the strain were too high.

Thanks for that (two). It's making some sense now. I suppose ramming the brake on and leaving it there for extended periods (including the two weeks X2 in the car park at Gatwick) might just have an effect! Clarity at last!

I would say the rod is off lesser mild steel than the parts it is joined to, and being 6mm lets virtually a 6" nail bent round a pin pulling on the handbrake hard and on steep hills over a period of time in some cases maybe 10 years it will stretch, as the cables front and rear will not.

I have seem compensator stretched from 5mm which once reached would mean that you can do one of two things take that up at the front adjuster from the 25mm to the 30mm using up the front adjustment totally, or at the rear and keeping the 25mm magic mark at the front this then would go on and on over the years until some clever person decided to add a few washers or an extra bolt at the front to save the trouble of adjusting at the rear, or even replacing the compensator for a new one which would again start the cycle over.

video below if you have not seen it
http://youtu.be/kHy6otDIjHU?list=UUcGnDN8CswzWpKlaa5H9g

even this stretched after six months of being on my car, that is how the stainless steel one came about.
http://youtu.be/A_iljrZfb?list=UUcGnDN8CswzWShpKlaa5H9g

The first stainless steel test
http://youtu.be/4UL2tuNVI8?list=UUcGn8CswzWShpaa5H9g

Below bottom is the up to date stainless steel compensator
http://youtu.be/hQJLuIie8cw?list=UUcGnDN8CswzWShpKl5H9g

http://youtu.be/IjlOWrNEw?list=UUcGnDN8CswzWShpKlaa5H9g