Rear brake cylinder

Post by **alan-spannerhands** » Tue Nov 14, 2006 4:37 pm

This is my first forum with the club so I'm not sure if I'm doing this correctly, but here goes.
I've got a problem with the handbrake on my Morris 1000 (1969 - 1098cc). The offside wheel can still be turned with the handbrake on. The cables seem Ok and I'm now in the process of trying to remove the rear brake cylinder but I can't get it off as the wheel hub prevents this. Is there an easy way to do this without having to remove the backplate?
Thanks to anyone who can help.
Alan

Post by **Axolotl** » Tue Nov 14, 2006 4:55 pm

Have you missed out some information? It's a big jump from handbrake not working to removing the cylinder as part of the solution.

Have you tracked the problem down to a siezed handbrake operating lever and not the cable, or just adjustment?

Is the handbrake moving the lever against the cylinder, or is the cable or lever siezed?

If the hand brake works one side but not the other, it could just be that the brake on the non working side needs adjusting up, which you do through the drum with the handbrake off. Tighten the adjuster with a big screwdriver until it locks the drum, then slacken off one click.

If the handbrake still won't lock that wheel, with the shoes correctly adjusted, it could be that the cable on that side is stretched, and you can take up the slack by adjusting the adjuster nut at the handbrake end, with the hand brake three ratchet clicks on, until you can just turn the wheel with a lot of effort.

That should lock the wheel when the handbrake is fully on, at about five clicks.

If you have really tracked it down to the cylinder, the book says you have to remove the rear hub to get it out, but I think I've read elsewhere that it should come out past the hub, it just needs some subtle wiggling. If it is a pattern not original cylinder, they are slightly bigger which makes it worse.

Post by **Relfy** » Tue Nov 14, 2006 5:20 pm

Yes as Axolotl says there is a whole lot of checking to do before you need to take the cylinder off. Get someone to pull the handbrake on -while you watch the cylinder - is it moving? In that case its probably just a case of adjusting it, or if that still doesn't work - how do your shoes look? Are they worn?

You should be able to get the cylinder off without taking the hub off - I managed it ok, so anyone can! There are folks who say you can't though so maybe theirs is somehow different to mine?

Post by **alan-spannerhands** » Tue Nov 14, 2006 5:21 pm

Thanks for your reply Axolotl. The handbrake cable seems to operate OK and I've adjusted the brakes using the adjuster as you've described and also tried tightening the cable using the adjustment nuts at the handbrake and the wheel still doesn't lock, so that's why I suspect something fishy about the cylinder. I'm not quite sure how the small lever on the cylinder operates the shoes however when I operate the handbrake it doesn't seem to do anything so I'm taking it off to have a look. I'll keep trying. Thanks again. Alan

Post by **rayofleamington** » Tue Nov 14, 2006 5:41 pm

Is there an easy way to do this without having to remove the backplate?

use a light tap from a big hammer - works every time to persuade a cylinder past the hub ;-)

A very common failure of the rear bakes is that the whole mechanism just seizes up. Often this is because the replacement part is sold without the (extremely important) rubber boot. Without a good fitting boot over the back of the cylinder (hiding the cylinder and most of the lever) it will quickly fill up with water, salt and dirt and won't last too long.

Generally people then just replace them again - with another part that comes as usual.. supplied with no boot. Maybe this is good repeat business for parts retailers?

Post by **chickenjohn** » Tue Nov 14, 2006 5:59 pm

I had to remove the bleed nipple assembly and unions from the back of the wheel cylinder. Then rotate the hub and you should be able to wiggle the cylinder out.

Post by **alan-spannerhands** » Tue Nov 14, 2006 6:17 pm

Thanks to you all. I'll just keep persuading it with the hammer.

Post by **Axolotl** » Tue Nov 14, 2006 8:50 pm

It does sound as though the cylinder might be siezed, or its movement restricted in some way. Assuming you can get it off, give it all a good clean, and reassemble using Copaslip to lubricate the slide (sparingly). That should help prevent it siezing again, in the absence of the rubber boot mentioned above.

You should definitely be able to see the hand brake cylinder actuating lever move the cylinder one way, and the other shoe the opposite way when you pull the hand brake on, but they don't move far.

One other possibility is that you have one or both shoes back to front. They should each have the cut-out (notched) end in the cylinder / adjuster slot. Otherwise you'll only be pushing less than half the lining against the drum when the brake works.

Post by **Axolotl** » Tue Nov 14, 2006 9:13 pm

Further to that last post. Only one shoe should have the notched end. That is the leading shoe, and goes at the bottom, with the notch in the adjuster.

You'll see when you look at the shoes that the lining doesn't cover all the shoe. One end of the lining fits close to the end of the shoe, the other end leaves an area of bare shoe metal showing.

The trailing shoe (the one without the notch) goes at the top with the exposed metal end furthest away from the cylinder slot.

Same thing applies, if these are the wrong way round, you won't get full braking on that wheel.

The reason for one trailing, one leading shoe is to give better braking in reverse. I wonder if your hand brake works if you try to turn the wheel backwards?

Post by **PaulP** » Tue Nov 14, 2006 10:07 pm

Hi Alan,

Is there an easy way to do this without having to remove the backplate?

On Sunday I started to refurbish the rear brakes as the fronts have been done. I got to the point where I couldn't remove the cylinder also due to the hub. (even with a little persuasion).
This week I have to find out the size of the large nut holding it in place and buy one (if anyone knows the size, I'd be greatful!!)

Post by **bigginger** » Tue Nov 14, 2006 10:49 pm

1 1/8 Whitworth

Post by **rayofleamington** » Tue Nov 14, 2006 10:55 pm

reassemble using Copaslip to lubricate the slide (sparingly

If you do usde that - use it very sparingly. Mineral based grease can wreck seals that are designed for brake fluid (although a bit of grease on the lever and outer piston is what I do too)

As for removing the hub to get the cylinder out - I strongly recommend to try brute force again before you do that. I've done quite a few and although I was certain on some of them that it wasn't coming through, it was always fixed by using 'right size hammer' and fortunately, fitting is much easier than removing.

Post by **PaulP** » Wed Nov 15, 2006 6:40 pm

it was always fixed by using 'right size hammer'

Just managed to remove the old cylinders using the method described above.... Just needed to put some muscle behind it!!

Post by **HarryMango** » Wed Nov 15, 2006 8:02 pm

PaulP wrote: This week I have to find out the size of the large nut holding it in place and buy one (if anyone knows the size, I'd be greatful!!)

As the Big Gingery one has said size is 1,1/8W - I still have some of these Spanners available plus loads of other Spanners - including 3/4W for Crankshaft Pulley/Starting Handle Dog - also loads of sockets & accessories. PM your wants.

Rog

Post by **tickman** » Fri Nov 17, 2006 1:07 pm

rayofleamington wrote:
Is there an easy way to do this without having to remove the backplate?
use a light tap from a big hammer - works every time to persuade a cylinder past the hub ;-)

did this job yesterday after reading all of the above posts and found the best way (and only for me) to get the cylinder out was with all the connections undone was to pull the top part of the cylinder out as far as i could and start to pull it up as much as possible, then use a large punch at the bottom rear and drift it up. came out in about 20 seconds once i had all the tools i needed (hammer and punch)

then the new part just dropped in by hand! same size hole and same part, how odd. will have to add it to life`s little list of mysterys.

Post by **bmcecosse** » Sat Nov 18, 2006 3:08 pm

It's a while since I had to do this - but isn't one section of the rear hub slightly relieved to make it easier to wiggle the cylinder out. The cylinder will almost certainly be hopelessly seized - best to fit a nw one - may as well get two and do them both. Then - slacken off the handbrake cables (and grease them) - assemble the rear brakes, bleed and adjust - and only then do you slowly tighten the handbrake cables until the wheels are locking equally both sides at whatever number of clicks suits you best.