richardg

i have a prblem with my 02 wrx. for some reason (i replaced the front pads about 3 months ago), my brakes are spongy at times and sometimes feel like the abs is doing overtime - i get a similar sensation as you would driving over a wet drain cover, ie no grip

anyone come across this before?

i ran it past someone earlier (who i will be calling to book the car in with), but wondered if anyone had seen similar probs....

TIA

Milamber

iTrader: (2)

odd one, have you had a chat with Xtreme or Mr Clutch in Chelmsford, they are doing us good deals at the moment. Say I sent you.

richardg

thought it was strange. spoke to a guy in margaretting who used to work at days i believe.
having mentioned the similarity between what i'm experiencing and abs on a wet drain cover, we wonder if it might be an abs sensor (apparently a ring behind the hub on each corner). starting to sound expensive

Milamber

iTrader: (2)

never heard of that before to be honest but then again I'm not an expert.

Milamber

iTrader: (2)

rule out the obvious and then whatever else remains no matter how improbable.....

Is it possible you just have rubbish pads, worn discs or not bedded in the pads properly. Have you got a good heat cycle through them?

richiewong

Could even be your tyres!

richardg

bedded in the pads over a couple of hundred miles and they;ve certainyl ha da good heat cycle through them...especially with the weather we've been having!
i went to central tyres the other day and they had a good look - pads, discs, brakes pipes, a hose near the passenger side wiper under the bonnet etc etc and couldn't find anything obvious.
i did consider tyres richie, but central tyres didn't point that out, so have ruled it out for the moment (although due to be replaced shortly anyway)
strange - maybe i should just drop in at mr clutch later today if i get the chance

stockcar

might help if you post the make, etc. of pads your using............also if the pedal is 'spongy' that more indicitave of a fluid issue, simply bleeding the brakes may help??

alyn

richardg

not sure of the make of the pads, but i've had the same before from the same garage in the past (had the car over 5 yrs now). when i apply the brakes, the pedal goes down, then sometimes it will drop a bit more without any increase in the rate at which i slow down. that's the point at which it feels "spongy", so i lift the pedal and apply again. sometimes it happens more than once, but i don't have to use cadence braking techniques to slow down - it's not that severe, but obviously still a concern

not sure if that helps any further or not really....?

stockcar

could also be a duff wheel bearing causing pad "knock off" means first press of the pedal aligns the pads and second press actually works correctly..........

alyn.

ALi-B

iTrader: (1)

I have found on older Imprezas premature ABS activation (ABS triggers=no brakes) can be caused by the front brakes not working as effectively as they should be, be it a pad compound problem, caliper issue or otherwise. Not persoanlly seen it on a newer model, but there is always a first.

First thing to rule out is checking if the calipers are working properly; replacing worn pads with new pads would push the caliper piston right back in the caliper body, which can make them stick and/or leak. Applying uneven forces on the brake disc and causing one wheel to be more prone to locking than another, and introducing air into the hydraulics.

Differring pedal travel to me suggest either be a bearing issues as mention by Alyn or worn disks, or disks with some minor surface run out (sometimes not enough to cause any obvious judder).

Car needs more proding a poking IMO;

Excercise and make sure all those caliper pistons work nicely. Makes sure the caliper slides are clean and all the crud has been properly removed and sliding surfaces and pins lightly copper-greased (all of this should have been done when the pads were changed) .

Then get the verniers on the discs and measure the average thickness, any heavy lips on the outer or inner edges requires the disc to be reground or replaced (depends on the disk condition and remaining thickness), and finally a dial guage on the disk surfaces to check the surface run-out. Again, this should really have been done when the pads were changed, but is often neglected.

richardg

thanks ali. only just noticed your reply

richardg

after all that, the problem seems to have been solved by the replacement tyres!
had been waiting for some toyos and now they've been on the car for a week, i've had no problems at all.

ALi-B

iTrader: (1)

Oh well, you got there in the end.

What brand/model were the suspect tyres?

(I'd like to put them on my potential blacklist, unless they are already on it )

bugeye69r

Hi ya....my growler does that and it may be the same thing ie the tyres, it has got TEIN coil overs all round and the set up is eating the front tyres off on the inner edge, but the brake feature you mentioned is exactly the same mmm maybe time for some rubber.

richardg

same toyo t1-r's, but they had a hard life ;-)

richardg

actually, i noticed this morning they were "s's", not r's. replaced with proxes4 ;-)

Milamber

iTrader: (2)

'S' for spongy sidewalls