944 E brake shoe movement

[Sunroof53]

The handbrake on my 944 brakes has been a pain since day one as when the brake is applied i can move the wheel slightly and feel the shoes moving inside .This appears to be a design error as there is no fixed point to the backplate like a type 1 drum.I have recently made an alteration so the shoes sit on the block at the bottom to start with (cable slackend off)and the adjustment then made with the star adjuster at the top.I have tried adjusting the shoes closer to minimise the amount they move off the block but then i get releasing problems .The whole design seems ver poor .

I have thought about making the adjuster fixed at the top but there is a lack of room as i would need 2 star adjusters and a fixed block in the middle.

Good to be back ,and thanks to people who posted link on STF

[Steve C]

Hi

Its a feature of many cars, my Toyota Prado does it.

Steve

[Sunroof53]

Thanks, i will live with it ok now i know there is nothing wrong.Just hope mot inspector doesnt pick up on it.

[evilC]

I think you may have the cables adjusted too tight. The shoes should sit on the block at the bottom and in the picture the swan necks should have no preload on them at all. The bottom spring should pull the shoes back to the bottom block. Are the shoes and the discs worn? Have you checked the wear limits on the drum? Your main adjuster looks as though its close to the limit - my new set up shows only 2 threads on the adjuster when opened out to just get the drum on, final adjsutment is only 1/2-1 full turn of the star adjuster.
Forgive me for being critical but the whole assembly is in need of some TLC with white grease to the contact points and I also coat the springs with a smear of grease. the whole thing should move smoothly, I can't see how yours can.
I had a deal of trouble setting the shoes on our set up but that was eventiually tracked down to a handbrake cable that had jump out of the quadrant guide at the handbrake end. Check this once and then again, again and again. (I only did 3 times)
As an aside, you can use BMW shoes instead of Porsche ones at about 1/2 price, they are identical.

Clive

[Sunroof53]

Thanks EvilC ,(photo is an old one)I have since given it a birthday .The cable was infact slightly too short(no adjust left) hence the gap you see in the photo.I have since cut 10mm from conduit in the backplate to rectify this .I did machine the drum and they are on the maxium limit .The shoes were new when i first converted but with the sticking problems they need replacing again.I did contemplate new discs but could not see how the movment will go away as when the brake is applied the shoes will still have to move of the block .Now i am not planning any handbrake turns but when the MOT inspector pulls the brake on the tester you can feel and hear things moving.It is however better now the shoes sit on the block at rest.
In theory the shoes could be adjusted very close and iliminate most of the movement and this is ok when i apply the brake and the car is completely still.If the car is on a slope and the car moves forward they stick again.this is why i have to leave them fairly slack(4 clicks to apply)so there is enough movment to fully release.

Anyway, i have left it for now and will revisit it with new discs and shoes in a few weeks .In my own mind i cant see it making much difference but logically its the only thing left.

What BMW uses those shoes?

Mike.

[evilC]

Hi Mike,

The brake shoe arrangement is a fairly common one that was used on a number of european models with rear drum brakes as well as discs. I remember my old '79 Opel Ascona having this arrangement. I can't see that there is anything intrinsically wrong with it but the arrangement is prone to requiring tight tolerences. If the adjustment is spot on then the bottom of the shoes will travel only a small distance before it all locks. That should translate to two clicks on the star adjuster and around a max of 6 clicks at the handbrake lever after everything is set.
I've never had a drum/disc combination near to the wear limit of the drum as the disc always wears much quicker than the handbrake portion. Afterall there should be no movement in normal use that would promote wear. Similarly shoes should last almost the lifetime of the vehicle, my Merc has done 270,000 on the original hand brake shoes and I periodically forget to take the hand brake off when I drive away, for a few yards at least. I think you might find new disc along with some shoes will cure the ailment as it will get rid of the accumulated tolerences.
I'm not exactly sure as to the BMW vehicle the shoes are off but I was in GSF and asked to look at some 5 series shoes that were identical. I think I had to drill some holes for one of the springs as the spring length was different but that was very minor compared with the £20+ I saved.

Clive

[Sunroof53]

The discs were second hand and the drum part was badly scored .in fact i went to a local breaker and most of his were the same which covinced me that it was either a problamatic design or an area which is frequently negelected on servicing.I will check some prices at GSF .

[al_kaholik]

Would be interested if we could find out the definitive years for the 5 series shoes. It was something I heard a while back, but have never got around to buying any, just mocking the whole lot up with my old knackered shoes.

[evilC]

Originally Posted by Skeeter

The discs were second hand and the drum part was badly scored .in fact i went to a local breaker and most of his were the same which covinced me that it was either a problamatic design or an area which is frequently negelected on servicing.I will check some prices at GSF .

Personally, I never buy s/h discs because the hassle they generate isn't worth it. By the time you factor in sourcing them, refurbing them and then having the sort of tolerence difficulties you experienced, plus they need to be from the same casting batch set to ensure the braking is even across the axle it is cheaper and more convenient to get new ones. I used to swap around drums in my youth and then wondered why I got inconsistant braking across the axle until I noticed significant casting colours/textures/ease of rusting between them. As soon as I had two sets that looked the same I noticed that the braking was more balanced.

Originally Posted by al_kaholik

Would be interested if we could find out the definitive years for the 5 series shoes. It was something I heard a while back, but have never got around to buying any, just mocking the whole lot up with my old knackered shoes.

Al/Skeeter, I'm 90% positive that they were from a mid/late '90s 5 Series BMW - something like a 525 or 535i. I will check the build file to see if I retained the receipt. I just went into the local store with an old shoe, said it was off a 5 series (I thought) and the first box they came back with contained the right ones.

As an aside I did the same for my car trailer brakes that were £72 per axle set (I nneded 2 sets)!! I checked with my local factor who said he thought they were Moggy 1000 and directed me to the local historic/specialist brake supplier who sold me a Mintex set for £18 per axle. Having ground a little notch they fitted perfectly. Moral - I bet the manufacturers of these specialist vehicles use mundane standard products, label it their own and charge a fortune, it just takes a little tracking down.

Clive

[al_kaholik]

For confirmation, these are 88-96 E34 5 Series shoes.

UK people, they are GSF part number B63035 £14.95 in contrast to the Porsche ones (P63605) at £29.95

[Sunroof53]

Originally Posted by al_kaholik

For confirmation, these are 88-96 E34 5 Series shoes.

UK people, they are GSF part number B63035 £14.95 in contrast to the Porsche ones (P63605) at £29.95

Thanks