As I got such a quick and helpful response to a problem with my wifes car earlier, I thought I'd be a bit cheeky and post a problem with my own car. Ive just bought a Rover 416 Sli auto, which Im very pleased with...smart car and nice to drive.
However, Ive noticed a noise coming from what sounds like the rear wheels when braking...Its not a screeching noise, nor is it a heavy grinding noise usually associated with worn pads...its difficult to describe in words but more of a "shhh" kind of noise with no vibration or grating felt through the pedal. It was sold with a new MOT and has only done 200 miles since so there's no way the pads should have worn....any ideas what it could be? It hardly sounds with light braking in traffic, and not really at all with heavy emergency type braking, only really with normal braking...and gets slightly louder as the car comes to a halt...The only thing I could think it was is dust maybe but after that small amount of mileage even dust shouldnt be a problem should it? It has alloy wheels if that makes any differance.
Once again, thanks in advance to abyone who might be able to help.
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Find a quiet back road.
Test at 10mph first of all and just apply the handbrake, which will only pull the rear brakes into operation. If you can handle the car OK, try this at higher speeds. Don't loop the loop and blame me!
Right, if it's definitely the rear brakes find a level spot (supermarket car park). Put car in 1st gear and release handbrake. Jack each rear wheel up separately. Spin wheel. No looseness, no tightness, no strange noise?
Look around rear axle. Anything chaffing, touching?
Good time then to return to supplier. Ask them to whip the drums off for a look. By the way, there's a rubber plug in the back of each hub, so you can inspect shoe thickness without having to take drums off.
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The Shhh noise sounds like the servo, but if it was it wouldn't be coming from your back wheels.
There's probably nothing wrong with it.
Suggest you try the action of normal braking with the car stationary to try to hear the sound again.
H
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Thanks for the reply Hugo...I tried that but no sound at all while the cars stationary...it definately only sounds while the wheels are moving...Ive heard that a problem with alloy wheels is you get a build up of dust inside the wheels...could this possibly be the answer? I may be worrying about nothing really as its certainly not the kind of sound of worn brake pads to my ears anyway, plus its only done 200 miles since the MOT.....but you know how it is when you hear a noise that shouldnt be there
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My guess would be the brake proportioning valve being off. The valve diverts brake fluid pressure to the front and rear Axles (wheels) seperately and by a pre-determined amount to prevent premature lock-up by one end before the other. If this valve is faulty, it could be diverting more braking force to the front wheels causing only a slight pressure to be applied to the rear.
The slight rear pressure would cause the pads or shoes to lightly rub the disc or drum creating the "shhhh" sound, which I take to be the sound of pads/drums lightly contacting or bru"shhhh"ing the disc/drums. During light stops the rears get no pressure at all, hence no "shhh". In a heavy panic type stop, enough pressure is sent to the rear brakes causing them to operate normally and not create the sound.
Of course as mentioned, this is just my guess so if I am completely off course, shhhh, don't chastise me too loudly 8-)
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I can't see what 200 ml.since MOT has got to do with it.All the MOT will check is that there are no leaks and that the brakes work and that's only if the MOT was done properly,not just written out without looking at the car.
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Your rear brake pads are worn out, the wear indicators are just touching the disc, causing the noise.
Take the pads out and have a looksee.
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Had the same problem with my old 96 416SLi Auto. Most likely the rear calipers have started to tighten up. They are what is known as "wind back" calipers and move on a threaded channel much like a bolt into a nut. After a while the rear ones give up the ghost and don't wind back, leaving the pads partially in contact with the discs.
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and the pads seizing in the pad carriers is commonplace too
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