39 replies to this topic

[lrostoke]

long shot but I had some drums a while back where the groove in the outer edge wasn't machined deep enough. Theres a lip on the backplate that sits in this groove, once tightened the lip rubbed on the groove, actually caused mine to lockup, I took them back and got them replaced.

Although you also say your old drums do it ???

Another long shot release the bleed nipples see if the pistons retract more.

Edited by lrostoke, 03 January 2012 - 02:28 PM.

[icedaddyuk]

I've just noticed something else. The springs I have used are different?

These are the ones I have used on the front from Minispares



They are different to those in Guess-works attachment?

I've just tried a brand new drum on the front (the ones I've used on the rear) and still the same problem so I don't think it's the drum.

[Deathrow]

Here is an exploded view of the front brake setups.

http://www.somerford...FrontBrakes.pdf

I don't see those springs used anywhere . Hopefully Guessworks will know.

[Guess-Works.com]

those springs are a compatible replacement, I've just installed them on a complete system rebuild. I did notice that one of the brakes were tight when installed but don't forget that the shoes will need to bed in and also locate themselves properly...

[Jono_h]

Have you pumped the brakes once yo've got the drums back on? This helps position the shoes correctly, and may free up the drum.

[ajpmsport]

When you replaced the wheel cylinders in April were the flexible brake pipes clamped? It could be that they were damaged not allowing the fluid to return, a long shot. Also would it be worth taking some sand paper to the corner of leading edge face (someone might know)
Or (last daft idea) put the old shoes back and see if the drums are free?

[matty...]

Have you got the right width shoes? Some of the early brakes used the 1 1/4" wide shoes (same as rear)? Im guessing the single leading shoe drums were slightly narrower and maybe someone has fitted these in the past?

Might be worth comparing with the ones you took out?

Edited by matty..., 03 January 2012 - 08:49 PM.

[icedaddyuk]

When you replaced the wheel cylinders in April were the flexible brake pipes clamped? It could be that they were damaged not allowing the fluid to return, a long shot. Also would it be worth taking some sand paper to the corner of leading edge face (someone might know)
Or (last daft idea) put the old shoes back and see if the drums are free?

The hoses were replaced with braided ones at the same time.

Have you got the right width shoes? Some of the early brakes used the 1 1/4" wide shoes (same as rear)? Im guessing the single leading shoe drums were slightly narrower and maybe someone has fitted these in the past?

Might be worth comparing with the ones you took out?

I no longer have the originals which is silly. I'm thinking this could be the case as it makes sense that the drums only bind when I screw them to the hub.

I'll remove the rears and fit them to the front to see if that works. Thanks!

[icedaddyuk]

I've fitted the brand new rear shoes to the fronts with the new drums and it no longer binds.

The only problem is it felt a bit too free if you know what I mean! I have to adjust to shoes forward a bit for it to bite. I'm home alone so can't ask the wife to press the pedal down to check what the bite is like.

Now could it be possible that even though my front drums are twin cylinder that they require the narrower rear shoes rather than usual front shoes?

And if not, will I lose much in the way of braking capacity by using the narrower shoes?

[matty...]

It could be the case that someone in the past has fitted single leading shoes, and it has worn a groove in the drum only part way accross, as you've now tried the full width shoes, they are binding on the step on the outer edge of the drum. Any chance you can post a picture of the drum and brake assembly as it is now?

The drums are the same regardless so the 1.5" shoes should fit. Definitely worth looking into, as its critical to get it right!

[icedaddyuk]

So what was the reason that some early models were fitted with the narrow shoes? Is it not to do with the back plates hence why the 1.25" shoes don't rub on the new drums but the 1.5" shoes do rub?

The 1.5" shoes are rubbing with both old and new drums so something isn't right.

[lrostoke]

how much are they rubbing , is it enough to lock up the wheel, or can you still turn the wheel. ??

Always found with front drums pedal was a lot better if shoes were nearly binding

[icedaddyuk]

With the 1.5" shoes and new drums and the adjusters not touching the shoes, I can't turn the wheel by hand which is why I know something is wrong!

With the 1.25" shoes and new drums, I can adjust the shoes to touching the drums ever so slightly and can turn the wheel by hand.

[lrostoke]

could just be unlucky and have a bad set of shoes. to much friction material

[icedaddyuk]

I think it's the width of the shoe not the amount of friction material which is causing binding as it only binds once I screw the drum to the hub and the brand new rear shoes fit.

Is it a problem running the narrower shoes on the front? will I lost much in the way of braking capability as there's already not an awful lot to lose!