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+--- Thread: Banging brakes (/showthread.php?tid=605)
Banging brakes - Michael - 30-12-2017
This has happened a few times after leaving the car in the garage for a few winter weeks. From memory I have experience of drum brakes freezing/seizing on but only in low temperatures or when handbrake is left on. We haven't had really low temperatures.
Car is always left with brakes off.
Reversing out of the garage brakes are free
Drive off down the road, apply brakes firmly, big bang followed by brief binding...then frees off and all is well. No evidence of anything nasty.
Surely shoes can't be sticking to drums because the brakes have been left off when not in use?
Levers checked afterwards, all fine, they should be, I did a job on them in the summer.
Would a seizing cross shaft produce the effect?
Or am I missing something...what would the experienced experts diagnose?
RE: Banging brakes - Reckless Rat - 30-12-2017
Mine does it too. I think it's caused by the self servo effect of the leading rear shoes. Once it's done it it's fine thereafter. I think a little attention with a rasp to the leading edge of the front shoe is all that's needed.
RE: Banging brakes - Chris KC - 30-12-2017
It's normal in proper cold countries to park with the handbrake off, to avoid shoes / pads freezing to drums / discs. It's also fairly commonplace for pads with metallic content to stick to discs when parked wet - results in a loud bang as you try to drive away.
However, if you can reverse out of the garage freely, neither is the cause.
Self servo yes but it's not supposed to be quite that dramatic - I'd suspect a bit too much free play somewhere. (Wasn't there a recent thread on much the same topic?)
RE: Banging brakes - John Mason - 30-12-2017
I am with Reckless on this one my Ruby used to do this when brakes were applied when going in reverse whatever the weather or temprature. Cure to rasp down the back edge of the linings (what ineffect is the leading edge when going in reverse).
John Mason.
RE: Banging brakes - Colin Wilks - 30-12-2017
Does the same thing happen without the initial reversing out of the garage? I am imagining the shoes shifting against the adjusters or plungers when braking in reverse, and consequently needing realigning once you're going forwards.
RE: Banging brakes - Murphy - 30-12-2017
(30-12-2017, 06:01 PM)d Colin Wilks Wrote: Does the same thing happen without the initial reversing out of the garage? I am imagining the shoes shifting against the adjusters or plungers when braking in reverse, and consequently needing realigning once you're going forwards.
RE: Banging brakes - Murphy - 30-12-2017
For many years I have experienced similar problems with brakes, often dismantling, fitting new cams, bushes etc with in reality little effect. Some 5 or so years ago, there was an article by Ian Moorcraft in the Association magazine,describing how to make a tool from a scrap brake drum to check the positioning of the brake shoes. In brief, the brake drum was cut down to leave a flat disc which could be attached to the hub using the three set screws. This enabled an arm to be attached which accurately described the same circle as the surface of the brake drum. (have just found the article 2011A)
Using this tool I found that in many cases the the brake shoes were not reaching the brake drum evenly and worse the face of the brake linings were not parallel with the drum. I think the rather nasty noise you describe on applying the brakes, is the moment when an offending brake shoe suddenly squares up to the drum.
Having checked the operation of the shoes, a way to rectify any anomalies is make up some 'over shoes' for the shoe pads (which must be in good condition to start with) to ensure that the shoes evenly approach the brake drum. Additionally, if the shoes are not parallel to the brake drum, a very light filing of the shoe pads can correct this but be careful as adjustment of the angle of the pad will be magnified at the lining face.
Hope this helps.
RE: Banging brakes - Michael - 31-12-2017
Thanks all, makes sense but doesn't happen in reverse. Good to know others suffer similarly. By way of an experiment I will start stamping on the brakes before setting off in an attempt to get things aligned. We'll see if it is worth the bother...
RE: Banging brakes - Tony Saward - 01-01-2018
Is there any chance of reprinting this article or providing a link? I am due to start sorting out the brakes on my GE Cup in the next couple of weeks and this tool would appear to be invaluable in ensuring that the brake linings are actually contacting the drums with as much surface area as possible.
RE: Banging brakes - AustinWood - 01-01-2018
My method of getting even brake lining contact is simply to remove the drums and inspect the linings. The area working on the drum is shiny. Were it isn't touching it's dull. I then file the shiny areas carefully with a fairly coarse flat file. After a couple of iterations I get even contact.
If the shoes are at an angle that will show as being shiny on one side of the lining.