Rear Drum Brake Questions

[MK21800]

Hi,

I finally got round today to attempting to replace my rear wheel bearings. Wheel off, drum was stuck. Hit drum with a hammer a few times. Hit drum some more. Still wasn't coming off. In the end, managed to get it off by just rocking in and levering it off with a large screwdriver.

Before I managed to get it off I put the wheel back on, and found to my suprise that I couldn't turn the wheel by hand. I'm sure the handbrake was off, because obviously I set it off to take the drum off. Double checked that to avoid making schoolboy error.

What I'm thinking is : If I managed to lever it off with a screwdriver, no bits were stuck or welded to other bits. However it was held with enough force to stop me turning it by hand. This to me would indicate that it was the brake shoes making it stick?

The car has been stationary for a bit, do we think the handbrake has seized in the "on" position? How do I go about checking and rectifying that?

Maybe the drum has a lip to it? I can feel a ridge around the outer edge on the inside. Does this mean new drum or can I just go ahead and use the same drum and just accept the fact that it may need a bit of levering in the future to get it off? Or maybe you might recommend some kind of machining?

[Village Idiots]

The lip round the edge (wear) is the reason it would not turn. As you attempted to remove it, this would jam. Sometimes you can back off the brakes by levering the self adjuster wedges upwards with a screwdriver through one of the wheel bolt holes. I would try and get the lip machined off; if it is deep, new drums are needed.

[MK21800]

Ok, well I've cleaned up a bit with brake cleaner. Now I can establish that the drum has indeed got the usual type of lip, but not very deep, I'd say about 1mm at most. The local parts shop I got the brake cleaner from have offered to grind the lip off for me (I don't posess the appropriate tool) for a drink.

Thankfully also the shoes look like they've got plenty of meat on them, I'd say about 4mm at least by sight. So looks like it should be good after I get the drums flattened out.

Cheers for that.

[mark1gls]

There is a minimum thickness for the brake drum (Haynes manual should tell this) so make sure if they grind off the lip the drum is not to thin.

If It was me I would put a new set of drums on insted of grinding the old drums, they are about £30 set from GSF, you will also need to put in some new wheel bearings with new drums.

[MK21800]

Gahhhhh....

Update. the ridge on my brake drums was so miniscule that the shop said they were fine. Once I'd cleaned them up, it was hardly noticeable, only slightly by feel.

I roughly put the old bearing back in the drum and offered it up to see whether it would go on out of interest, but the drum became stuck on the shoes and would't press on, leading me to believe that the shoes needed pressing in again. Consultation with the Hayes manual confirmed this. Trying to push them in however didn't prove too successful, and I noticed a little fluid coming out of one of the pistons of the wheel cylinder when trying to do this. Oh dear. The shoes did push in, but didn't stay there, I noticed the pistons of the wheel cylinder went in but when released, just pushed out again and I was back to square one.

Then my attention moved to the wheel cylinder thinking maybe it was faulty, hence the pistons not staying in. I then had the not so bright (on investigation) idea of pressing the brake pedal. Not such a good idea. I had moved the wheel cylinder rubber boots out of the way to investigate for leaks. When I pressed the brake pedal, brake fluid came suirting out of one of the pistons of the wheel cylinder. I have since learned that this was the shoes overextending due to thinking the drum was worn. I made the mistake of pressing the brake pedal with the drumoff. Bollocks.

I'm a bit stuck to know what to think now. I'm reckoning the drum had difficulty coming off due to the shoes overextending and pressing against it for some reason. I'm also wondering whether I've broken my wheel cylinder in the process of pressing the brake pedal, or whether it just needs the pistons and seals pushing back in again. I'm unsure how to check for wheel cylinder leaks if I do manage to push them back in. Does it just leak out of it's own accord? I didn't notice any when I first took the drum off. It seems that they didn't want to go in all the way with the pressure of the return spring, leading the shoes to be sticking out and stopping the drum coming off/going on.

This is gettin a little messy. Any thoughts?

[ianaudia4]

Brake fluid everywhere! I myself would be going down the route of changing the shoes, wheel cylinders and drums, at least then you will know they are all sound, not worth taking any chances with brakes.
When I last changed the rear shoes and cylinders I think it cost about £30 including a litre of DOT 4 fluid, all from ECP.

[MK21800]

Brake fluid everywhere! I myself would be going down the route of changing the shoes, wheel cylinders and drums, at least then you will know they are all sound, not worth taking any chances with brakes.
When I last changed the rear shoes and cylinders I think it cost about £30 including a litre of DOT 4 fluid, all from ECP.

Yeah I see what you mean. Once that fluid has come out, it's not worth taking chances.

The stub axles look a bit scored but do not feel scored when felling with the fingernail. I was advised that this was probably ok for the new bearings.

Well I've got new bearings ready and grease. I think I'm gonna go down the route of just replacing the cylinders, bearings, shoes and drums on both sides and possibly the stub axles, depending on whether I can get away with those or not. In situations like this I consider it an omen that it was probably about time to relace this stuff anyway

[eefy]

I got a kit like this for mine-

http://www.ebay.co.uk/itm/REAR-BRAKE-DR ... 51a0e9f2cd

i also spent a few extra pounds on a spring set as well :)

[MK21800]

Thanks for that link.

I already have the wheel bearings though, as that was the original job I was intending to do.

I had another look at the brake assembly today, yeah it doesn't look like the newest in the world, maybe about time it was all changed.

I notice VWHeritage do parts made by "Meyle" - are these any good? I like VWHeritage, bought some stuff off them before, they're good. Meyle worth shooting for? I've worked it out at about a ton for the parts for both wheels, which isn't too far off the price of the link you gave me. That price would be shoes, drums, and spring set (I think they call it an "installation" set)...

Aside from that, stub axle - scored but not feelable with the nail (feels smooth) - is that ok?

Back plate - do these need replacing? Or can they just be cleaned up a bit.

Might as well think this through properly if it's gonna be stripped.

[mark1gls]

I would not worry about the stub axle as the bearing runs mainly on the face of the metal ring which you replace with the bearing, (the meatal ring should come with the bearing and is fitted to the brake drum).

[Nate]

you need to back off the brakes to easily fit/remove the drum. run some coarse emery paper round it to take the shine off it (same with the new shoes) before fitting

if a wheel cylinder has been leaking, replace it. for the cost of them, it's not worth messing around. if it carries on leaking once you put it back together, you'll be putting another set of shoes on in a months time

where abouts are you? if you're local i'll come do it for a few beers