Knocking noise - brakes?
31 March 2005, 08:47 AM
#1
Knocking noise - brakes?
Morning all,
My car’s a UK MY98 turbo saloon, which has developed a new noise!
I don’t get any noise if I just drive into or around town; the noise is only really apparent after a longish run (such as 30+ miles) – I presume something’s warming up in that time.
After the run, when crawling along, a regular knock starts, increasing and decreasing with road speed. At first I thought it might be a CV joint, but as it goes away if I touch the brakes; I guess it’s brake-related!
Brakes are AP 4 pot calipers and 330mm grooved discs up front, standard rear discs, and DS2500 pads all round. Front discs have shiny outer faces (seen through wheel), but both inner faces are more rusty. Stone guard shields are still fitted (but maybe I should remove them?).
I had a shufti all round, and all pads have plenty of material. Also checked that there are no split CV boots, and there doesn’t appear to be any play in the wheel bearings. No obvious signs of anything rubbing that I can see.
Unfortunately I’m away from home, so am making my best visible inspection in the car park of my girlfriend’s apartment block!
Any thoughts, tips, pointers appreciated.
Cheers,
Steve
My car’s a UK MY98 turbo saloon, which has developed a new noise!
I don’t get any noise if I just drive into or around town; the noise is only really apparent after a longish run (such as 30+ miles) – I presume something’s warming up in that time.
After the run, when crawling along, a regular knock starts, increasing and decreasing with road speed. At first I thought it might be a CV joint, but as it goes away if I touch the brakes; I guess it’s brake-related!
Brakes are AP 4 pot calipers and 330mm grooved discs up front, standard rear discs, and DS2500 pads all round. Front discs have shiny outer faces (seen through wheel), but both inner faces are more rusty. Stone guard shields are still fitted (but maybe I should remove them?).
I had a shufti all round, and all pads have plenty of material. Also checked that there are no split CV boots, and there doesn’t appear to be any play in the wheel bearings. No obvious signs of anything rubbing that I can see.
Unfortunately I’m away from home, so am making my best visible inspection in the car park of my girlfriend’s apartment block!
Any thoughts, tips, pointers appreciated.
Cheers,
Steve
)
05 April 2005, 02:08 PM
#3
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Sounds exactly like what I've been hearing for the last few months. The noise was very odd. It started as a light metal-on-metal rattle and got louder, 'heavier' and it became obvious it increased in rate with roadspeed up to about 50mph when I couldn't hear it anymore. It seemed to only do it in a straight line too, cornering would quieten it down, and it needed time to 'warm up' after the car had been parked, even when the engine was warm. I thought this was the bearing grease getting up to temperature, but was probably the pads/discs. One other point was that the noise would stop with even the lightest application of the brakes. Eventually, it sounded like 2/3 knocks at once and got pretty loud.
At first I thought it was a rattling headshield, so I cut them off and wrapped the headers. Then I tried a replacement driveshaft which 'cured' the knocking for a day or so before it came back. Then I changed the wheel bearing, which 'cured' the noise for about 3 days before it came back. Finally, I took the calipers apart, regreased the sliders and copper-greased the pads and haven't heard it since. I really should've done that first!
Rubbing stoneguards gives a very distincting scraping thin-metal-on-metal sound (this happened to me after the bearing swap), rather than a knocking.
Hope this info helps.
(BTW, mine is a MY98 Sport but running 2-pot calipers up front)
At first I thought it was a rattling headshield, so I cut them off and wrapped the headers. Then I tried a replacement driveshaft which 'cured' the knocking for a day or so before it came back. Then I changed the wheel bearing, which 'cured' the noise for about 3 days before it came back. Finally, I took the calipers apart, regreased the sliders and copper-greased the pads and haven't heard it since. I really should've done that first!
Rubbing stoneguards gives a very distincting scraping thin-metal-on-metal sound (this happened to me after the bearing swap), rather than a knocking.
Hope this info helps.
(BTW, mine is a MY98 Sport but running 2-pot calipers up front)
07 April 2005, 06:32 PM
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Steve,
Had similar noises coming from my car too (MY02 WRX). Thought it was the audible pad wear things kicking in so pulled the wheels off to find loads of lining left all round.
"??????" says I.
However, after all the salt and crap of winter roads up here, all the pins, pads and springs were looking heavily corroded.
Pulled the pads out all round, copper-eased everything and fired the pads back in with new pins.
Robert's yer fathers brother as they say. Haven't heard a thing since and the brake feel seems a lot better too.
Stewart.
Had similar noises coming from my car too (MY02 WRX). Thought it was the audible pad wear things kicking in so pulled the wheels off to find loads of lining left all round.
"??????" says I.
However, after all the salt and crap of winter roads up here, all the pins, pads and springs were looking heavily corroded.
Pulled the pads out all round, copper-eased everything and fired the pads back in with new pins.
Robert's yer fathers brother as they say. Haven't heard a thing since and the brake feel seems a lot better too.
Stewart.
07 April 2005, 10:19 PM
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Loud vibrating/chattering noise from brakes.
Steve, Check out my answer in this thread. Sounds familiar....
May also be a bit of crap & rust on the back of the pads is holding them in place (ie what the preload clip should be doing) until you have done a few miles and pressed the brake a couple of times which will loosen it off. Don't think its anything to do with warming up if it is from the brakes.
Cheers, Daz
Steve, Check out my answer in this thread. Sounds familiar....
May also be a bit of crap & rust on the back of the pads is holding them in place (ie what the preload clip should be doing) until you have done a few miles and pressed the brake a couple of times which will loosen it off. Don't think its anything to do with warming up if it is from the brakes.
Cheers, Daz
Last edited by dazc; 07 April 2005 at 10:25 PM.
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