brake squeal

[markandsuefoss]

My brakes have started to squeal a little just before coming to a stop. I guess that means cleaning out the drums. Is it best to simply brush out the dust once I've got the drum off or is it better to use brake cleaning fluid. I have heard of people spraying the the back plate with the shoes in positions to wash out any dirt and debris. Is it OK to do that? I mean it is OK to get it on the linings. The linings by the way are OK - they are not new, but have a good depth of friction material.

[dalebrignall]

i would think its just dust , just take the drums off and brush them clean id advise wearing a dust mask

[robandsophie]

Hi,

Good level particulate mask, plus wet clean (appropriate brake cleaner) don't just blow the dust out of the drums, unlikely, but could be asbestos lining depending on age of shoes.
You can catch the run off in the plastic bag lined bowl, then dispose of appropriately. All nice and tidy.

[markandsuefoss]

So when using brake cleaner I spray it all over the brake components. I mean there is nothing that I need to keep the cleaner off.

[mogbob]

I endorse dalebrignall's suggestion , especially the mask precaution. Brake dust is not good for the lungs. If the shoes are really old they could be asbestos composition.
Spraying the back plate is fine , might as well do a "proper job ". Lay out some old newspaper beneath and blast it with some
brake cleaner ( away from you ) starting at the top and working down ,back plate and shoes. If you want to be precious ,you could cover the shoes friction surface with masking tape , bending an excess , doubled back " tab " on one end. You can grab the tab to remove later. Wipe the fluid and dirt off with clean rag or kitchen roll type paper. Do the same to the brake drum as well and inspect carefully before replacing. If it's a rusty or glazed surface a light rub with emery paper wouldn't hurt. Clean surface again before refitting.

Some people swear by putting a small chamfer on the leading edge of the shoe , so that the initial contact point is smooth and doesn't "catch" as the brakes are applied. A file will take off just a little material. You say the screech is just before you stop so this advice may not be relevant.
If you have the tools and experience , applying Copper ease to the " feet " of the brake shoes where they contact the wheel cylinder and where the sides touch the raised parts on the back plate would help.
Get back to us , if you need any further help or clarification.
Bob

[markandsuefoss]

Thanks for all the advice. I have limited experience. Yes the squeal is just before I stop. Funny thing my modern car does it too and the garage tries to charge me £40 each time to clean the discs. It's not really loud but just a bit annoying. I hear other modern cars do it to. I think it is since they stopped using asbestos. I'll have a go on my Traveller at the weekend. Thanks.

[kennatt]

take the drum off and have a look before messing with brake cleaner,which was designed for disk brakes, it could well be that it needs new shoes,squeal is normally cause by metal on metal ,in disc brakes its metal back plate rubbing on the caliper piston , cured by copper slip , in drum brakes again highly likely to be the back plate of the shoe touching the drum,can touch before during and just after brake application ,check it out first before looking elsewhere good luck

[Sleeper]

...that being said,my VW Polo has for the past three years had squeaky rear brakes,plenty of meat on the shoes and drums......but it disappears after some braking...I put it down to damp getting into the friction material and drying out with use/heat..

John

[markandsuefoss]

My car is a '71 traveller - should the hole in the drum through which the brakes are adjusted have a rubber cover?

[dalebrignall]

yes take the bung and aline the hole with the screw to adjust , turn clockwise till the drum locks then go back 1 click .

[markandsuefoss]

I don't have any bungs - they are obviously missing. Or were they ever not fitted?

[firedrake1942]

I have had mine nearly 40 years and have never seen them, but they are shown on the parts list for back and front brake drums.

[myoldjalopy]

If you have Series II wheels with the little hole for brake adjustment, as well as in the one in the drum, there is a school of thought that suggests that leaving these holes unplugged allows brake dust (one cause of squeal) to exit the drum.....

[markandsuefoss]

Thanks everyone - after cleaning them we did 1200 miles touring Ireland over Easter and not a squeal.