19 replies to this topic

[Mrt88]

hi all

ive had a search and came accross this probelm a few times.

 

im finishing off rebuilding my rear brakes. Everything has either been completely striped and cleaned/painted or replaced.

everyhing has gone on fine, used loads of pictures. but no matter what i do the new shoes rub on the new drum. 

 

all my parts are from mini spares if that helps.

could i take some wire wool to the pads just to knock off some high spots ? i can upload a picture in the morning if thats going to help anyone.

 

thanks again all,

Theo

[Stu.]

They will rub until you run them in. If you can turn the drum fairly easily by hand with the drum giving a little resistance and can hear the drum rubbing on the shoes a little that should be ok assuming you've set the adjusters correctly.

Oh, and I wouldn't mess with shoes or pads braking surface material to try and adapt them to fit. Assuming you have the correct set for the car, they should fit properly if the backplate, cylinders, adjusters, drum and fittings are correctly set up.

Edited by Stu., 25 April 2014 - 10:17 PM.

[Lsurt95]

have you tried winding the brake adjuster all the way out?  Also make sure the hand brake is completely off and if that doesn't work slacken the handbrake cable off slightly.

 

hope this helps

 

 

Liam

[Mrt88]

Thanks for the reply buddy. The subframe is also new. Everything is of the car at the moment. Yep the adjuster is completely out, and it's got copper grease on it too.

[Mrt88]

Well I can turn them by hand. They don't catch all the way round, just part way though a full rotation. Once the sub is on I'll run them for a day or so and see.
Does that sound ok ?

Edited by Mrt88, 25 April 2014 - 10:18 PM.

[Mrt88]

Nearly everything is new so I don't see any issues. I'm sure I have everything in the correct way round. Any pictures would be an amazing help.

[Stu.]

Sounds about right. Light rubbing is ok. Once you start driving and the shoes bed in you'll need to 're set the adjusters a little otherwise your braking efficiency will be compromised as will your handbrake travel (if it's the rears).

[cradley-heathen]

i have had this problem a few times myself with certain suppliers brake shoes. i have also spoken to others who have also had the same problem with the shoes from the same supplier im reffering to. i wont mention any names, but i would say i have absolutely no problems with any other product from them.

[Stu.]

The shoes will properly centre and seat in the drum once brake pressure is applied through the cylinders, so the shoes half rubbing on hand rotation with newly installed ones may just be because they are not properly centred.

Edited by Stu., 25 April 2014 - 10:44 PM.

[Captain Mainwaring]

Sounds like the wheels may not be bolted up either?

[Mrt88]

Nope no wheels yet

[cal844]

What i do is back the adjuster off,wind the handbrake front adjuster out and then fit the shoes and adjust everything back up

[tiger99]

I have known them to not run very well with the wheels off. Try fitting the wheel nuts backwards, using the flat side to clamp the drum up tight. Add a few washers if needed. It may run better then, because it may help to keep the drum properly centred.

 

But from what you have said, I think that everything is fairly normal for new parts, as quite often the rubbing is worst at certain rotational positions, due to a build-up of tolerances. That improves with running, and plenty of use of the brakes.

[dklawson]

And for the record... "properly adjusted" does not mean free too turn without rubbing.  With a rim mounted on the hub and elevated off the ground you should be able to spin the wheel, hear a bit of drag, and the wheel should stop turning within about 1 revolution.  If it spins more than that, it is too loose and you are likely to find you need to press the pedal a long way and/or pump the brakes.

[Vipernoir]

I've found with a lot of modern shoes that the heels are too long or badly shaped - where the heel of the shoe sits in the wheel cylinder and the brake adjusters is subtly the wrong shape.

 

If you offer the shoes up to the drum they are probaby the correct diameter and round enough to work.  When they are sat on the hub they can effectively become an oval by being pressed out too far.
*If* you can wind the adjusters in far enough to get the drum on (not guaranteed) the the contact patch is tiny.
2 minutes with a file to dress them back to a more acceptable shape and you'll be fine.

 

First time I did this after working out the problem was a revelation.  Went from failing on brake efficiency to a handbrake-turn monster in half an hour.  Not had rear brakes so good since the late 90s...