Thread: For the Drum Brake Gurus - I have a binding front brake.

Mmm .... Your bottom photo shows width of shoe fit's into the groove area of the backing plate

When you have the adjustment screw wound in ....Are you sure that the brake shoe is not getting jambed between that groove & the brake drum???


.... As it could be a case of the brake shoes being wider than original .. or fitted the wrong way round?

First thing I would do is pull the drum off and see if anything has changed.
(The most common reason for this problem is contaminated brake shoes, usually either brake fluid or oil from the hub, but could be just greasy hands, or even, in a rarely used vehicle in a damp climate, rust)

Apart from these possibilities, I would be looking for one of the following:-

1. pull off springs incorrectly assembled or broken (if turning the wheel backwards frees it, this is more likely)

2. adjuster snail loose on its shaft or just turns too easily

3. If it has the posts the shoes rest on sideways adjustable, then these may be loose, missing or incorrectly adjusted.

4. Unlikely, but could be junk in the hydraulics acting as a one way valve

5. Loose wheel cylinder.

6. Unlikely, but check - you do have the right wheel cylinders on both sides? Right and left are different.

Let us know what it turns out to be.

John

I had to do the same modification to my brake shoes when i replaced them because they would not fit. I have also had binding left hand brake before too it is a real bitch when doing a steep decents on gravel usualy ends up being oil and crap on the shoes.

Paul

Also .... When buying new brake shoes ... A preliminary check on receiving the correct "diameter of shoe" ..... is to place them in the brake drum and make sure they are the same diameter (no gaps)

Originally Posted by mike 90 RR

Mmm .... Your bottom photo shows width of shoe fit's into the groove area of the backing plate

When you have the adjustment screw wound in ....Are you sure that the brake shoe is not getting jambed between that groove & the brake drum???


.... As it could be a case of the brake shoes being wider than original .. or fitted the wrong way round?

I don't believe it is getting jammed in, the shoes are sitting in the exactly same place as the originals were.

It is possible that the shoes are wider, but I have now taken the drum off twice and I didn't notice any unusual rubbing inside the drum.

I doubt I fitted them the wrong way round also, because I made sure that the adjustment cam was aligned with the post which it acts against.

Originally Posted by JDNSW

First thing I would do is pull the drum off and see if anything has changed.
(The most common reason for this problem is contaminated brake shoes, usually either brake fluid or oil from the hub, but could be just greasy hands, or even, in a rarely used vehicle in a damp climate, rust)

Apart from these possibilities, I would be looking for one of the following:-

1. pull off springs incorrectly assembled or broken (if turning the wheel backwards frees it, this is more likely)

2. adjuster snail loose on its shaft or just turns too easily

3. If it has the posts the shoes rest on sideways adjustable, then these may be loose, missing or incorrectly adjusted.

4. Unlikely, but could be junk in the hydraulics acting as a one way valve

5. Loose wheel cylinder.

6. Unlikely, but check - you do have the right wheel cylinders on both sides? Right and left are different.

Let us know what it turns out to be.

John

Thanks for your detailed suggestions John.

1 - Springs


I don't believe I put the springs on the wrong way? The photo above shows the spring fitted... Although looking at it now i'm wondering if the lower spring should be attached to the rear shoe rather than the front one.

2 - Adjustment cam's are a little worn but you can't turn them without a spanner or ratchet

3 - I have never touched these as i'm usure what you adjust them to.

4 - Hydraulics are working fine, the cylinders retract, it is just he shoes that are staying engaged.

5 - Will check this

6 - You can't actually fit them the wrong way around, The bolt holes and the brake line done line up.

Originally Posted by paulthepilot_5

I had to do the same modification to my brake shoes when i replaced them because they would not fit. I have also had binding left hand brake before too it is a real bitch when doing a steep decents on gravel usualy ends up being oil and crap on the shoes.

Paul

Hi Paul,
It is interesting that you have said this! I can't live with this, it's so dangerous when 4wding to have one of the front wheels locking up on you before the others. When I had the binding problem when 4wding I was able to alleviate the symptoms by scratching all the buildup off the shoes. But it is still not a fix.

Originally Posted by mike 90 RR

Also .... When buying new brake shoes ... A preliminary check on receiving the correct "diameter of shoe" ..... is to place them in the brake drum and make sure they are the same diameter (no gaps)

The thing is that all 4 shoes were supplied wrapped together so you can't really place them inside the drum without tearing up the packaging, I fitted 2 to one side and the drum slid on fine. I fitted the remaining 2 and the drum wouldn't fit. So I swapped the drums over and I found that it wasn't the drum causing the problem.

Could this be caused by worn wheel bearings??

Originally Posted by stirlsilver

1 - Springs

I don't believe I put the springs on the wrong way? The photo above shows the spring fitted... Although looking at it now i'm wondering if the lower spring should be attached to the rear shoe rather than the front one.


4 - Hydraulics are working fine, the cylinders retract, it is just the shoes that are staying engaged.

5 - Will check this

Haven't fitted drum brakes in 20 years .... BUT would suggest the following

Had a look at your photo and agree with the spring should be on the front shoe .... as it needs to pull the shoe & piston of slave cylinder closed ..... ON second thoughts .... ARE you missing a spring???

AS the one you have on now keeps the trailing shoe hard up against the slave cylinder
AND another is required to keep the shoe & piston of slave cylinder closed .... Check for missing spring!!!
WHEN there are 2 springs opposite 2 each other & connected .... this will balance the force of the springs on shoes and will keep the shoes .... balanced & centered

The spring as it is fitted now is pulling the shoes to one side .... rather than putting force on closing the piston & shoe into the slave cylinder (= brakes off)


To check shoe diameter fit to drum .... Place drum on floor and place/fit new shoes to inside and check for a diameter match .... But I think you took a photo of the problem


Mike

Regarding the shoe fit to the drum, on a couple of drum brake jobs I did in the dim dark past I had the shoes radius ground to fit the drums. I don't know if this service is still avaiable but those brakes were far more effective than others I had done by simply fitting a set of new shoes.

Roger

As far as I can tell from the photo, the spring shown is correct. The other shoe has an identical setup. The springs should be pulling strongly on the shoe, as they are close to the anchor end (getting them onto the anchor should be quite difficult!). I suppose there could be a problem if one spring has got overstretched during installation. Also, check if there is more than one hole near the right place on the shoe - it could have extra holes for some obscure reason - I know the ones I just looked at do, although not near there.

John