Hi There,
Progressing with the rebuild of my 1970 500F but....
I am struggling with the assembly of my rear brakes, I am using brand new brake shoes, back plates, springs, cylinders, hand brake levers and drums, all assembled and good to go or so I thought.
When I tried to gently put the drum over the new assembly it would not fit. (measuring the widest diameter of the assembled shoes confirms that its not going to fit eat the moment)
I wondered if there might be a manufacturing tolerance in the plate or something so assembled the other side but the same problem.
Being new to this game I'm sure that I'm missing something really obvious but can't work out what!
Any help much appreciated!

Just done this also. That right brake shoe should be able to push in a bit more at the top. Also try knocking the brake shoes up towards the cylinder. Be careful doing this as you don't want to damage the shoes. Use a bit of wood against the shoes and gently hit with a hammer

Are they the correct cylinders? Have you fitted the front by mistake?

Hi thanks for such a speedy response, just tried some gentle taps as suggested but no movement I'm afraid?

Franko500 said:

Are they the correct cylinders? Have you fitted the front by mistake?

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This would make no difference. There are a number of different bore cylinders that all have the same mounts and outside dimensions. If it is all new then you are probably dealing with a coat of paint and getting the shoes centralised.

Hi Sean, I assume so as I have a disc brake conversion, so only purchased rear cylinders, just checked my suppliers website for photos to identify which is which but the photos are the same, ill give him a call in the morning.

Hi there should be some means of adjusting the brake shoes.I would not think they are self adjusting so behind the back plate will be some kind of adjuster possibly having a square head. Wind this in or out will move the brakeshoes in or out. If it has self adjusters you will have to adjust this. As Toshi says have you centralise the shoes. The drum should go on easily. On the cylinder pistons there used it be a slot for the end of the shoe to locate into.Do not know if it is the same on yours.

Hi thanks for your response there is no adjuster behind the back plate but the shoes themselves have automatic(?) spring adjusters around the shoes pivots I assume that these compensate for wear. No means of adjusting these manually as far as I can see? not sure how you would centralise them either?
sorry being a little slow here.

Hi SB. It was a bit of a long shot. Was there a slot in the cylinder piston? From your picture it looks as if the top of the left hand shoe is sticking out a bit more than the right hand shoe where it goes into the piston. I would have thought with a bit of pushing and shoving you would have been able to centralise the shoes. Do they look to be central?

That right hand shoe needs to push in further than that. It would suggest the piston isn't pushing in far enough. I would take the shoes off again and then take the rubber on the cylinder off and you'll be will be able to pull the piston out and the springs inside. Check that it is fully pushing in, you should be able to do it with your fingers.

Here is a picture of what it should look like.

Hi, yes there is a slot in the cylinder piston that the end of the shoe arms slots into.
if you pull on the handbrake lever you can get them to move obviously but there is no play around the pivot once the springs take over.

Thanks for that, ill give it a go after work, and let you know how I get on!

I used two tyre-levers, one each side, jammed between the return lip of the back-plate and each brake-shoe, and gently forced both of them inwards at the same time. You need to take care not to let the return springs defeat you and ping the whole lot off the backplate pins.
"Micro-adjustment" was achieved using a rubber mallet.
It's worth checking that the handbrake mechanism is located correctly in the shoes.

Just noticed what it is. The handbrake mechanism is fitted wrong. On the right handbrake shoe the shoe should also fit into a v slot as per the left hand shoe. Thats why it is sitting proud

Hi you've cracked it PAOL0 well done

Hi, thanks for you reply, may be my iffy photo, but both V Notches are engaged I think as when I pull the lever the both engage with the pads and push them apart. I have just 'released' the handbrake lever by pushing them in the opposite way (to the handbrake being applied) until they are both loose and can be jiggled around so the V slots don't touch anything but unfortunately no inwards movement in the pads.
(sorry for being such a pain!)

I can see Damian's train of thought. The lever that goes to the left hand shoe looks correct but where it goes to the right hand shoe it is sitting too far forward, it should be tucked behind the right hand shoe but in your picture it looks like it caught on the right hand shoe preventing it from going in further.

See picture below, the same side this time. The only other thing I can see that is possibly causing it, is the nut that holds backplate to the hub is preventing the lever from sitting flat, the nut has one of its edges pointing upwards and it may help if the flat is horizontal? If that makes sense?

Hi helpful people, thought id be logical so have just removed everything from the backplate (Cylinder, hand brake levers springs) leaving just the two shoes.
The hub does not fit even then so something more serious is the issue, incorrect parts?

Strada Bianche said:

Hi helpful people, thought id be logical so have just removed everything from the backplate (Cylinder, hand brake levers springs) leaving just the two shoes.
The hub does not fit even then so something more serious is the issue, incorrect parts?

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Have you tapped the shoes inwards towards the centre of the hub so that the friction adjusters are at the closest point to the linings? They are in an oval hole.
You could possibly do that by tapping the adjusters themselves with the shoes off the car. Use a piece of wood or something to avoid cracking the friction washers.

Hi Peter,
Not as yet but ill give it a go, I was anxious about using too much force on the pads surface also my supplier is sending a pair of pads from a different manufacturer as apparently the brand I have has has a couple of 'known issues' in the past.
On another note I have just set my rear hub resilient spacers / bearing preload that allows the 1lb weight just to move at the drums radius (on the bench without grease or seals), very happy with myself. I then when I did the final assembly with grease the effort to move them is increased. I'm guessing that I have over greased them?
many thanks for your advice