M series handbrake cables/setup

[MattT350T]

Hi all.
I'm having problems setting up the handbrake on my early M.
I cannot get it to less than 7 clicks without having the shoes grabbing when fully released.
I've also almost run out of cable adjustment.
So, I was wondering a few things.
1. How many clicks should these handbrakes operate at? (3?)
2. What is the correct procedure for setting up the hydraulic and hand brake adjustments when fitted. I,e do we setup the shoe adjuster first and then adjust the handbrake adjustemnt to suit or vica versa please?
3. Are replacement cables for the ones photographed available please?
Many thanks in advance everyone!
Matt

[nwarner]

I always adjust the brakes first by turning the adjuster until they lock then turn back one flat and check they rotate freely then adjust the handbrake. I was told by an MOT tester a few years ago that as long as the handbrake doesn't come up too far and stops the car it should be fine but I don't know if things have changed since then. TVR Parts do handbrake cables for M series TVR's

I hope that helps

Nige

[MattT350T]

Hi Nige.
That is the exact, classic method that I've followed but it's not resulted in a satisfactory solution for some reason.
I'm leaning towards cable stretch....but at £70 a pair I'm trying to exhaust other options/clues/ideas first...eeek.
Thanks Nige.

[GAjon]

Do your cables go into a common block, as this picture?

If they do, what I have done is remove the round bar link (from the hand brake lever to the block) and replaced it with threaded bar.
This gives you further addjustment at this end.

[phillpot]

GAjon said:

....................... replaced it with threaded bar.
This gives you further addjustment at this end.

Nice solution, could a bit more thread be cut on these to give same result?

[MattT350T]

So....new handbrake cables bought and fitted.
They are 5-10mm shorter than the old ones and offer some increased adjustment range accordingly.
However, once fitted and all adjusted up, I still cannot get any less than 7 clicks without binding occurring with the handbrake in the fully off position...
AV's article on M servicing explicitly states to aim for 3 clicks.... I have run out of ideas and any help will be most gratefully received.....
Matt

[GAjon]

I’d be rechecking everything s the wheels again, drum ovality, springs and sliders all operating correctly, make sure the shoes aren’t binding on the back plates etc.

You know the handbrakes on Ms was never cutting edge (to the point they’re actually pretty crap!)

[nwarner]

Is there any wear in the levers that operates on the shoes? and with the brake drum off and you pull the handbrake does it move the shoe enough? If the brakes are adjusted correctly the lever shouldn't have to move the shoe very much. This is the lever I mean.

Nige

[Adrian@]

There are two versions of the cable support (5.12/9/10234) early versions, which uses a clevis pin and thackery washers allow float in the outer cable and it is near impossible to adjust and the later version which is has a 5/16 bolt and washers (which version have you got)? A@

[Dollyman1850]

GAjon said:

I’d be rechecking everything s the wheels again, drum ovality, springs and sliders all operating correctly, make sure the shoes aren’t binding on the back plates etc.

You know the handbrakes on Ms was never cutting edge (to the point they’re actually pretty crap!)

I machined my last drums totally Round jon... They were perfectly round but unfortunately this made the brakes muchworse when approaching Clervaux at about 120mph.... They were so bad that one of the pistons just popped out Handbrake had just been fitted but even that didn't pull the car up

N.

[GAjon]

Dollyman1850 said:

I machined my last drums totally Round jon... They were perfectly round but unfortunately this made the brakes muchworse when approaching Clervaux at about 120mph.... They were so bad that one of the pistons just popped out Handbrake had just been fitted but even that didn't pull the car up

N.

You should have cleaned the mistic off , like your dad told you!

[MattT350T]

Good afternoon all.
Many thanks for the responses yesterday and this morning.

RE: There are two versions of the cable support (5.12/9/10234) early versions, which uses a clevis pin and thackery washers allow float in the outer cable and it is near impossible to adjust and the later version which is has a 5/16 bolt and washers (which version have you got)? A@

The car is an early '72 car. At the drum end the inner cable is supported/slides inside a 'sleeve' that is connected to a bracket very some very loose thackery washers. It allows a lot of angular freedom at this location. The outer cable runs out of the 'sleeve' to the a clevis pin connection through the lever arm at the drum end.

With the drum off, I have noticed that the internal shoe spring on that side doesn't quite have enough spring tension to pull the shoe 'legs' back into 100% off position. It was only a tiny bit but was there as I could manually pull the lever end towards the drum and see/feel movement. I started to clean up that area last night to reduce friction etc. I don't feel that that will be sufficient to give me 4 clicks worth of motion though.... :-(

I will check shoes are not rubbing on the back plate thank you as well.
I will check wear in the lever too.

Would anyone recommend any mods from later versions of the handbrake assembly to help with this please?

Cheers
Matt

[MattT350T]

[quote=nwarner]Is there any wear in the levers that operates on the shoes? and with the brake drum off and you pull the handbrake does it move the shoe enough? If the brakes are adjusted correctly the lever shouldn't have to move the shoe very much. This is the lever I mean.

Nige

I will check and measure the movement with the drum removed, thankyou.
I can't help but feel that the handbrake itself is not a brilliant design due to angle of the lever arm on the rod attachment side I.e the opposite end of the handbrake from that we pull. Because of the angle at the released position, the rotary motion of the lever results in only a small linear motion along the direction of the cables. (i.e image moving from 9 to 7 on a clockface) To me it should move from just after 7 to just before 5 to maximise that linear motion....anyways it is what it is.
Thanks Nige, I'll check..

[Dollyman1850]

GAjon said:

Dollyman1850 said:

I machined my last drums totally Round jon... They were perfectly round but unfortunately this made the brakes muchworse when approaching Clervaux at about 120mph.... They were so bad that one of the pistons just popped out Handbrake had just been fitted but even that didn't pull the car up

N.

You should have cleaned the mistic off , like your dad told you!

[MattT350T]

I'm an idiot and mistyped my previous paragraph above.....

The car is an early '72 car. At the drum end the OUTER cable is supported/slides inside a 'sleeve' that is connected to a bracket very some very loose thackery washers. It allows a lot of angular freedom at this location.

The INNER cable runs out of the 'sleeve' to the a clevis pin connection through the lever arm at the drum end.


Cheers
Matt