Posted Last Week by kea
Thanks.
>>The brake pedal is not a footrest!<<
Yes. That's what the accelerator is for  . I wasn't resting my foot on the brake pedal. I found out that very light touching of it stopped the noise because I was testing the car to see what the noise was and what made a difference.
I'll be getting a qualified mechanic to do any work on the brakes. But as illustrated by my earlier shock absorber story I am not going to go in blind and stupid when I take the car in. I'd like to be well informed, and me having a look first and getting to see what bits are what is useful. If it's just a matter of taking the wheels off and looking I think I can manage that without a mechanics degree 
I had a look through the wheels this morning and the discs all show quite different degrees and kinds of wear. Is that normal? One disc is lovely and smooth. Two others have concentric grooves. One has some pitting just in some places.
>>
It is possible that some gravel (you said you sometimes drive off paved roads) is caught up in the system. It may be scrubbing along as you drive but when brakes are applied it is effectively immobilized.
<<
Sorry, I haven't followed this bit very well. Do you mean a bit of gravel is embedded in the pads and intermittently somehow comes in contact with the discs when not in use, or do you mean that it's in another part of the brake mechanism?
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Posted Last Week by kea
Just read your earlier post, and see you were meaning in the pad 
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Posted Last Week by Taliesin
DIY brake system maintenance, including pad replacement, isn't normally much more complicated than changing a set of plugs.
Special equipment is only needed for rotor resurfacing, or similar tasks.
Care should be taken with regard to skin contact or inhalation of dust from the brake pad material. Use jack stands, good work light etc..
Google 'how to change your brake pads' will likely provide..
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Posted Last Week by Taliesin
>>What I don't understand is why it would make an intermittent noise when the brakes weren't being used. Can anyone explain?<<
The wear indicators make noise when they begin lightly contacting the disc. When you alter the amount of pressure, even slightly, the indicators are pressed more firmly against the rotor surface, and stop vibrating, or at least change vibrational frequency
http://auto.howstuffworks.com/auto-.../brakes/brake-types/disc-brake4.htm
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Posted Last Week by kea
 That link has a good photo in it.
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Posted Last Week by Br. Robyn Hoode - Now with added Ginge.
How's it going Kea? I've not been near a computer all weekend or I'd have been around to help, sorry!
If your brake wear indicators are touching the disc then they would probably be bringing on the warning light Often times a bit of light almost rhythmic noise is something slightly loose or vibrating (which is why a touch of pressure will stop it) or caught in between the friction surfaces.
Concentric ring marking on a disc is quite normal. But if it's more than marks (a slight ripple under the finger) then you have scored discs. how much friction material do you have still attached to the back plates of the pads (you should have a metal section probably around half a cm thick which will have a slightly smaller friction surface attached to it. If this is any thinner than the back-plate then you should consider getting them changed soon as a rough rule-of-thumb (though the amount on the original pad will change depending on the manufacturer).
Can you tell if the handbrake clamps the pads or if it has an internal handbrake drum (some vehicles do have this)? Check where the handbrake cable attaches. If it goes into the caliper then it'll be the pads, if it disappears into a backplate behind the wheel hub, then you could have a seperate handbrake system which adds another section that will need checking.
If you've checked all of these I have just one or two other suggestions - wheel bearings. If the hub bearings are slightly dodgy then again, a slight tightening of the brakes could stabilise the hub causing the noise to lessen or stop.
To test these, when the vehicle is up and on axle stands (lift the whole back end and stabilise) give each wheel a good spin by hand (mind yer fingers! Dont put them through the holes in the wheel to spin it!) and have a good listen at the hub. there will be some rubbing noise from the various parts and the pads etc but there shouldn't be any rumble or grinding really. It's hard to explain but you know a bearing rumble when you hear it...
Once you've spun the wheels, hold the tyre top and bottom and try to tilt the wheel slightly top to bottom in and out (so, pressing at the top and pull at the bottom and vice versa) with enough pressure to move the wheel, but you're only trying to sort of wobble it, if it were to move, you would only expect it to tilt a degree or two, at the edge, so it's slight movement you're looking for. Some movement could well be normal (depends on the type of bearings you have) as a little end float allows for the bearings to expand when they heat up in normal use. If you have a lot of movement, then you could be looking at damaged/worn bearings.
Bearings will be £££ but they hold the wheel on so dont put it off.
Lastly, it could also be a prop bearing or some sort of bushing etc related to the 4 wheel drive, but that's not likely. The location of the sounds is unclear (though you said central which is why I mention this, it's *possible*) and not always as indicative as you'd think. Try the brakes and wheel bearings first and see what happens.
Shock absorbers you can check the bushes normally visually to a point. If they look a bit melted or there's gaping holes you might need new bushes. Also, if when you heavily press down on the corner of the vehicle it rebounds up and settles, your chockers are more or less fine. If it bounces more than that, your damper (which is what a shock absorber is) on that corner is not damping the spring movement.
Er... Hope that helps?
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Posted Last Week by kea
Thanks! Hopefully will get to it on the weekend.
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