Discussion
Right lads. After the recent front caliper and disc upgrade the squealing has become unbearable. So i decided to fit some anti squeal pads to the back of the brake pads. As they are brand new brake pads they were tight to say the least to get them in. Now the drivers wheel is binding to the disc (I can still turn the wheel by hand but is definitely binding) will i be able to run the car till the pad wears down so the wheel runs free again or should i just wait until the pads are ran in then fit the anti squeal pads and put up with that god awful noise for another 2000 miles or so? Another idea was to take the pads off and take them an engineering firm to take them down a tiny bit so they fit. Other options are greatly appreciated.
Dix
Dix
They should not be that tight fella but if you can turn by hand they should ok. Drive a few miles and check that they and the calipers are not getting over hot. Assume you have the anti squeal shims fitted and they are the right way round? Bit of copper grease on the back of the pads will also help.
Chris
Chris
Spray discs with WD40
Hey Dixie, here's a link to their website, i got the tube from my uncle, i'll ask if he can get anymore and send it down to you if you like. http://www.bgprod.com/products/brake.html
marcus
marcus
marcus1875 said:
Hey Dixie, here's a link to their website, i got the tube from my uncle, i'll ask if he can get anymore and send it down to you if you like. http://www.bgprod.com/products/brake.html
marcus
That would be great if you could marcus cheers bud.marcus
Dix
dixiebabes said:
will i be able to run the car till the pad wears down so the wheel runs free again or should i just wait until the pads are ran in then fit the anti squeal pads and put up with that god awful noise for another 2000 miles or so? Another idea was to take the pads off and take them an engineering firm to take them down a tiny bit so they fit.
If your pads are that tight in the calliper then either they are the wrong type or something else is causing them to bind.Perhaps one or more of the pistons is not receding?
If you run the car with pads as tight as you describe I think the over-heating will distort the disc or worse.
Sometimes pads can bind on the sliding surfaces of the calliper such that the local area needs to be thoroughly de-rusted to provide smoother surfaces.
Regarding Brake Squeal and how to deal with it, have a butchers at this article I put together with information gleaned from a 1987 Ferrodo bulletin, which is therefore relevant to symptoms experienced by owners of cars produced at that time.
Preventing Brake Squeal
Squeal is a side effect of braking which attracts more attention than once it used to. Continued refinement has reduced the amount of noise produced by a car engines, exhaust and transmission to the extent that noise from the brakes is unacceptable, and out of keeping with the smoothness and comfort of the ride.
Squeal comes mostly from the metallic parts of a brake installation, such as drum or disc, shoes and backplate. The energy input comes from the rubbing of the linings when the brakes are applied, but it will likely be the metallic parts which vibrate and emit noise. Trends in design and lightness of suspension components, brake mountings and the brakes themselves seem to have made audible vibration more easily excited. Choice of friction material can sometimes reduce vibration by absorbing energy. Also brake manufacturers have attempted to introduce design expedients with the aim of eliminating it.
Most of the anti-squeal measures introduced by way of design are such as cannot be changed or tampered with in service. However, there are a number of points which should be checked, when squeal is a problem, as well as confirming that the brakes have been serviced properly.
Drum Brakes.
Before shoes are refitted or replaced, the brake should be cleaned thoroughly; dry dust should be removed with a damp cloth, liquid spray (the use of water with a little domestic liquid detergent is OK) or suitable vacuum apparatus. Industrial alcohol is the only suitable solvent for hydraulic brakes along with proprietary brake cleaner. On re-assembling, lubricate all metal-to-metal contact points with suitable proprietary brake grease (available from stockists) to assure free movement and prevent corrosion. Typical lubrication points are the tips of sliding type shoes, pivot points of other shoes, shoe platform edge support points and steady post tips.
Few people use re-lined shoes these days but even new shoes should be inspected for unsatisfactory riveting or bonding this being a relatively common cause of squeal. Linings must be in close contact with their shoes, loose rivets will allow the lining itself to vibrate, or even be noisy themselves. Riveted and bonded shoes, which are otherwise interchangeable, are likely to have different vibration characteristics, so trying an alternate type may be effective.
When shoes are first fitted, a large measure of drum contact should be achieved very quickly, unless the drums are worn oversize. It is permissible for the ends of the linings (say 10% of lining area at each end) to take a little while to bed in, but failure of the crown of the linings to contact the drum can promote squeal. Finally, all pull off springs should be undamaged and correctly located, the brake components should be undamaged and the brake mountings tight.
Disc Brakes.
Before pads are refitted or replaced, callipers should be cleaned, as described for drum brakes, and inspected for seized pistons and other defects. Pads should be of identical size, shape and material, and preferably of the type recommended by the car manufacturer or squeal and other undesirable side effects may occur.
An early anti-squeal expedient was the forming of a step on piston faces and, where this method is in use, the alignment of the step must be correct. Later came metal shims, which achieved the same. These must be correctly assembled and should be lubricated with brake grease on both faces. Brake grease should be used on the backs of disc brake pads not used with shims, including some with depressions pressed in, and on those edges which contact the calliper. Some disc brake pads have the lining offset to prevent squeal; usually they have 'handed' backplates, so cannot be fitted incorrectly.
Another expedient is the use of a resilient material to form a shim on the backplate, this allowing some realignment to occur between the calliper and the pads. When no such material is used and brake grease is not effective, a pack of suitable self adhesive material can be purchased which is cut to shape and stuck to the clean backplate. After peeling off the protective paper, cover those areas which contact either the piston or the calliper body. Offcuts can be used to build up a second layer where the piston makes contact.
'Roughing Up' Linings.
Abrasion of lining surfaces ('roughing up') is unlikely to cure squeal and will only necessitate reconditioning and rebedding before the linings again give the optimum performance.
Chamfering the edges of disc brake pads also unlikely to be effective in curing squeal and by reducing the working area, will only raise the surface temperature and increase the wear rate.
Summary.
Attending to some or all of the above suggestions will probably effect a cure for brake squeal but if all else fails, be aware that, as designed and installed, brand new brakes very likely did not squeal. Poor maintenance, wear and ineffective cleaning, along with using inappropriate components may all contribute to the problem so it is essential to ensure that all the mechanical elements of the braking system are as near to the original design parameters as possible.
Hope it helps.
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