Blimmin Handbrake

[Mark01]

Hi All,
I have renewed the handbrake shoes discs and hand brake cable in the hope of getting a hand brake that can hold the truck. I can adjust the shoes nice and snug at the drum but what ever I do the bell cranks on both sides have to move nearly the full pull of the hand brake before the shoes move out to the drum .
I have cleaned and greased everything so all is working. Can anyone tell me if there is any adjustment on the bell crank as it seems to me this is where all the play is now.
The only way I can get a hand brake without it being right at the end of the lever travel is to put some shims under the adjusting nut by the handbrake lever.
Is it possible the small piece of cable that goes from the bell crank to the shoe can stretch.
I have been messing about with this on and off for the last two sunday afternoons and its starting to frustrate me that I cant get it to work very well at all.


Cheers, Mark

 

[Citizen Brown]

i have fitted new shoes and cranked arms to mine too. It seemed to work fine to start off with (handbrake engaged a few clicks in) but has now gone slack. Not had chance to look at it but it feels like cable has suddenly stretched or some point of adjustment has slipped!

 

[Chris]

Have you adjusted up the handbrake stops on the back of the brake shield? It's all covered in the maintenance thread you know. You remove that slack and then adjust the cable.

 

[Mark01]

I adjusted it all up as per your thread Chris. As I printed it off last weekend so I could refer to it in the workshop. The play is in the bell crank I'm sure. With the wheel off I can adjust the shoes so they are locked on, then I can push the bell crank nearly the length of the guard it travels between before it stops. To take this play out with the slack adjuster it would need to be nearly 4 inches long. I don't know what parts to get to put this right.

Cheers, Mark

 

[Chris]

Mark that can't be right. Something going on in there. If you wind the cog out hard against the inside of the drum, rotate the wheels with a bar and wind them out some more etc then adjust all the slack out of the crank with the rear adjuster there isn't any slack left. There is no way on earth that the adjuster bolt could be 4 inches long. There cannot be that much slack in the pivot point on the bell crank. There just can't be. The little wire cable might stretch a touch but I personally doubt it. somehow you must be losing movement at the top or bottom of the shoe. Get some pics and post them. You must be missing a component.

 

[Mark01]

Hi Chris, I will strip it down and get some photos on for you, it might only be at the weekend though I will see if I can finish work a bit early and get the drums off one evening. With the drum off you can push the crank back everything moves ok but only right at its full travel do the brake shoes move out.

Cheers, Mark

 

[Chris]

Ok mate. We're here to help. You don't get much movement in the shoes when the drum is actually off.

 

[Mark01]

That's it, The actuator arm or whatever it is that the cable from the bell crank fits to does move from the instant you push the crank back, for whatever reason the shoes are not moving until right at the end of the travel

 

[AndyCook]

I am sure bob murphy in Edinburgh found these parts wore at the pivots creating slack in system and he replaced them


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[Richard Jackaman]

I've got mine off the truck at the moment and am also having trouble getting enough tension on the cable so will check the pivots for play and report back.

 

[Dan W]

Like you I've replaced the shoes, all of the springs and fittings and the handbrake cable and can only get it to work slightly by putting spacer washers under the nut at the handbrake. If I follow the FSM method of adjusting the handbrake it's nowhere near tight enough.
Like Andycook says there must be another component of the system that generates some free play.

 

[Richard Jackaman]

Just checked and the Pivots on mine have no play at all. Last time I adjusted it the rear crank adjusters were about 50 mm from the backing plate and the handbrake cable adjuster in the cab had about the same amount of washers as packing. Worked just enough to get through the MOT but not enough to be useful.

 

[Mark01]

I managed to get home yesterday and whilst the mrs and kids were out I whipped the o/s/r drum off and took some pictures. I can now strip this down almost as fast as an f1 pit stop its all been on and off so many times the last couple of weeks.
In one of the pictures you should see how far the crank is from the back plate, this is how far it needs to be to make the shoes activate.
If I slaken off the handbrake cable and check the play in the bell crank there is very little play like 5-10mm.
Hopefully some one will see straight away if anything has been put in upside down or back to front.

Cheers, Mark.

Cheers, Mark

 

[Dan W]

The one thing that did help is bedding the shoes in, don't know if you've tried that? after adjusting the shoes and cable, take it for drive and every so often partially activate the handbrake, this should then smooth the shoe down to fit perfectly on the inside of the drum. Afterwards allow it to cool and adjust everything again.
This gave me a fairly good handbrake for a while anyway.
Also, I can't remember if there's supposed to be a spring just underneath the adjuster that holds the bottom of the shoes together.

 

[Chris]

Really hard to say from the pictures. But some questions. If all those pictures were taken as it stand - the adjuster stop should not be off its stop point. The only time that moves is when you pull the cable. Now you may have pulled it for effect for the picture. But it shouldn't be there. Secondly I can't see the shoe return spring that runs between the bottom of the two shoes behind the starred adjuster wheel. I realise the drum is off, but it looks like the adjuster screw is fully wound in. You shouldn't really need to do that just to get the drum off. There is plenty of meat on the shoes but they look to be in horrible condition. Like they are all pitted or something.

I have to wonder if this is just something that you are not getting quite right inthe adjusting procedure. Even if you need to bed the shoes in like Dan says, you should still get the proper lever feel. You may not get it holding, but that is due to bedding in. If you are not getting any feel at the lever, something's just not right.

 

[Dan W]

Mine are off the stops too. I think it's when you put the spacers under the handbrake nut. I've a similar issue where nothing happens until you get to the end of the cranks travel, even if the shoes are wound right out. It's almost as if only half of the shoe is in contact with the drum?

 

[Chris]

The handbrake lever must be completely disconnected in the cabin ie slack, with the little stops against the plate on the back of the brakes before you start. You can't do this if you start with the bell crank anywhere other than in the completely off position.

In fact, you need really to screw the little stop bolts in so that there bell crank can be seen to be totally retracted. If it's touching, then the crank may still be able to move back a little more.

 

[Dan W]

I'll try cutting off the stops (mine are past adjustable) and putting a nut and bolt on to see if I can get it closer to its back plate before adjustment. I'll give it a go in the next couple of days and let you know if it improves things Mark.
Cheers Chris.

 

[Mark01]

That's the problem, if I slacken the handbrake cable right off so the stops are resting on the backplate, I can adjust everything up nicely until you take the slack out of the handbrake. I will wind the nut at the lever right to the end of the thread on the cable and when you pull the hand brake the cranks only come to where you see on the picture with no shoe activation. Only with packing out at the handbrake lever and brining the cranks out to where they are can I get the shoes to lock.
When everything is slack as I push the bell crank the slightest movement starts pulling on the lever on the brake shoe, but you have to have all the travel before the shoe actually move out. At the moment I cant see why there is so much movement in the actuator arm before the shoes move. Could it just be a crap set of shoes I don't know.
The return spring is there its just bad photography.
Im not sure why they have pitted although they have been binding a bit as there was a fair bit of dust in the drum when I took it off.
Perhaps I will start right from scratch at the weekend and see what happens.
Let us know Dan, their must be a resolve somewhere.

 

[Chris]

I'm baffled if you tighten up the star cog through the hole in the disc drum so the wheel is fully braked then back off one or two clicks then the smallest movement of the lever in the cabin will pull the brake full on
If you operate the crank from behind the wheel it should do the same