Original pads can 'brake' bank

Please assist. My 2008 Mazda3 1.6i makes a "tsirrrrr" sound when I apply the brakes. It started after the front brake pads were replaced earlier this year.

I took it to a Ford/Mazda dealership in Silverton, Pretoria, and they claimed to have cleaned and adjusted the brake pads, but this did not make any difference. Is this normal, and what can you recommend from your experience?

It's just irritating to drive a car with noisy brakes. - Jonas

Jonas, I don't think Mazda would have designed the brakes to make a noise like you describe. From what you say, the most likely explanation is that the problem lies with the new pads.

Ever since the use of asbestos in brake pads was banned due to the potential dangers to human health, manufacturers have been struggling to find a satisfactory replacement.

The mix of materials that goes into the friction lining of a brake pad is a highly specialised science. It always involves a compromise - if the lining is too soft, it will be gentle on the disc, but the pads would need frequent replacement - if it's too hard, the pads will last relatively long, but they will wear down the discs.

Pads also have to cope with high temperatures, and are required to have anti-fade characteristics. Asbestos had a unique combination of properties which no other compound can match as yet.

My information is that Mazda dealers can provide pads equal to the original equipment pads fitted at the factory, but these are horrifically expensive.

Knowing what the reaction of customers will be, they normally fit the locally produced pads sold under Ford/Mazda's Motorcraft brand name.

These are by no means inferior pads, but they are more prone to noise problems than the OE items. A chirping noise such as you describe can result from glazing of the pads.

This happens when the friction lining acquires a hard, glass-like surface under the influence of temperature and pressure where it runs against the disc.

Mazda dealers have found that it sometimes helps if they remove the glazing and chamfer the edges on the linings.

Another possibility is that anti-rattle springs on the pads were installed incorrectly (or omitted) when the front pads were replaced, but this should have been picked up.

It is also possible that the noise originates in the rear brakes, which are also discs.

Generally speaking, it helps a workshop a lot if the owner can identify whether a brake noise comes from the front of rear of the vehicle.

A good way to eliminate all doubt is to get someone to lie in the back of the car with a seat backrest lowered, and listen when you brake.

If the noise comes from the rear, they will hear it clearly. In your case, since the rear pads are still top-quality OE pads, I think you'll find it's the front pads. The best chance of getting rid of the noise will be to try a different brand of pad.