Brakes sticking after cylinder change

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I'm in the process of changing the front brake cylinders on my 1960 1000. First side - no problem. Second side - one or two little niggles, but everything is now fitted. But here's the problem, when I put the drum on, it's quite tight. Once it's on, the wheel doesn't turn - as if the brakes are binding badly. However, if I adjust the brakes through the little hole, I can wind them a long way up. If I can do that, surely the brake shoes can't be binding? Of course, it's a bugger to get back off again.

I've tried pumping the brake pedal several times, but this doesn't make anything better. I haven't bled the brakes yet, could that cause this problem? I should mention that I haven't changed the brake shoes on this side.

Has anybody else seem a similar problem? I'm beginning to wonder whether the brake backplate has been in the sun all day and so expanded and the drum has been in the cool of the garage. Clutching at straws? I should say so.

Have fun,

Mikey.

[bmcecosse]

Do the cylinder pistons appear to be sticking out of the cylinders? Shoes on right way round ? Springs not rubbing on the hub ? If you fit new shoes on one side - you must also fit new shoes on the other side. Maybe the shoes just need to be 'centralised' - although turning the drum should do that right away.

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Would I be right in saying that the shoes only need to be the right way round so that the adjuster slots into the keyed side? If so, then yes, they are the right way round. I thought about fitting new shoes but I figured if the old ones don't fit, then putting new ones on will just make the problem worse, won't it? However, I have fitted new shoes on the other side so I suppose I should try putting the new ones on this side as well.

Have fun,

Mikey.

[bmcecosse]

I agree - but if the adjusters can be wound up - there must be clearance !

[BitMoreBlurred]

True. Suppose I ought to go and give it a go then.

[MarkyB]

A picture of the tight side might help, with the drum off of course.
I normally offer the drum up and if it doesn't want to go on easily, feel around the edge that is meeting the shoes and tap the metal part of the shoe till it all lines up.

One useful tip I was given was that when the shoes are fitted right, the friction material should appear to have slipped in the direction of the wheel travel. So the top shoe should have the friction material towards the front of the car, and the bottom one towards the rear.

Hope this helps.

[BitMoreBlurred]

I think that I did notice that it appeared to slip as you suggested, but I'll check.

I've just replaced the shoes, and the problem is still there. Is it possible that the drum has warped? I put the drum on the wrong way round and span the hub, but the drum didn't look completely circular.

Have Fun
Mikey

[MarkyB]

There is no wrong way round for drums so discount that.
Did the adjusters drop into their place on the cylinders?
There are ridges on top of the cylinders they should fit in.

[bmcecosse]

Easy check - swap the drum with the other side. Slight 'warp' is not uncommon.

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You misunderstand me. I put the drum onto the hub so that the inside of the drum was facing outwards, then I could spin the drum and look at the shape and balance of it.

As you say, the problems are at the front of the top shoe and the bottom of the back shoe. In fact, if you look at the picture, you can see the scuff marks on the top shoe. I haven't got the drum on all the way with the new shoes, as its very tight and I'm afraid that if I force it, and the brakes still bind, I won't be able to get it back off again. In order to get it on, I would need to use the rubber mallet. Am I just being too cautious?

[frame][/frame]

[bmcecosse]

It's very difficult to get the drum on square when you put it on backwards - yes - I understood what you had done! You may need to file a leading/trailing edge on each shoe - this is quite common. And a little 'scuffing' will soon wear away with your first road-test! Are the adjuster cam brackets fitted down snuggly into the groove in the top of the cylinder piston ? That one looks like it may be 'riding up' slightly??

[beero]

From the photo it looks to me like you have the top shoe on the wrong way round.

[bmcecosse]

No - can't be - the shoes only have the adjuster notch at one end!

[MarkyB]

A bit of encouragement with a rubber mallet is OK.
There is probably a bit of a lip on the drum and once the shoes clear that it'll be fine.

[BitMoreBlurred]

Busy day yesterday, but finally got the job done. Talk about making a mountain out of a molehill.

I did try swapping the drums, but I still had the same problem. The key to sorting it out was filing the leading edges of the shoes. It seems strange to have to wear down your own brake pads, but whenever I mentioned the problems I was having to "an old boy" they all said "oh yeah, we had to do that all the time". I'd never heard of it before, but you live and learn.

Thanks very much for all your help and suggestions.