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Can brake pads go 'off' ??....
martinq357 - 6/8/13 at 09:35 PM

Has anybody experienced brake pads gradually loosing their 'bite'?

Our 03' Ford Galaxy had gradually lost its braking effiency, almost to the point of scaryness!!! They had done about 20k miles in 3 years and had approx 9mm of meat left on them.

I replaced the brake fluid (which needed doing) and that improved it a bit. I've now replaced the pads and the difference is astonishing...!

The surface of the removed pads appeared to have small cracks or fissures in them.

Just wondered if anybody else has had a similar experience. In 27 years of driving I've never had pads go this way.......

tegwin - 6/8/13 at 09:41 PM

It is possible that when you fitted the new pads you dislodged some air or cleared some binding within the pistons when you pushed them back into the caliper body....


I guess it is possible for the pads to absorb moisture over time perhaps and their properties to change, but I would suspect the issue more lies with the hardware pushing them?!

NigeEss - 6/8/13 at 09:46 PM

Pads can overheat quicker as they get thinner but don't usually lose cold "bite".
More likely are the things Tegwin says above.

britishtrident - 6/8/13 at 09:51 PM

Pad friction coefficient will change permanently if the pads are overheated over long periods and become "carbonised" , also if the pads are sticking in the calliper or the calliper guide pins are sticking it will cause poor braking.

It pays to buy OEM quality replacement pads rather than generic pads.

loggyboy - 6/8/13 at 10:21 PM

9mm seems a lot for 20k of use, is the wear even?

martinq357 - 6/8/13 at 10:40 PM

They were all evenly worn and all 4 had approx 9mm left on them.

After I bled the brakes, they did feel better but still lacked bite. The slide pins weren't that clean but the calipers slid back easily.

Thanks for the response, I'll be keeping a close eye on them in the future.

Slimy38 - 7/8/13 at 07:15 AM

I've had brake pads getting glazed, that seems to reduce braking ability quite considerably?

Grimsdale - 7/8/13 at 07:31 AM

yes, lots of gentle braking does glaze pads, i make sure to put the stoppers on hard when coming up to roundabouts when there isn't traffic ahead of me.

DH2 - 7/8/13 at 07:42 AM

Also worth checking the state of the inboard face of the discs, if you haven't already.

DH2

britishtrident - 7/8/13 at 09:49 AM

One aspect I didn't mention is wet weather is really bad for brake pads, water soaks into the pad surface, when the brake is applied it turns instantly into super heated steam creating little blast holes in the softer parts of the pad material.

mcerd1 - 7/8/13 at 09:52 AM

quote:
Originally posted by britishtrident
It pays to buy OEM quality replacement pads rather than generic pads.

+1

I used to buy ordinary pads (like ferodo 'premier' etc...), I've also tried EBC's uprated pads - and the were all s**t
fine for your granny running down to the shops at 20mph, not so good if you want to use them more than once a day.... (i had smoke pouring off the ebc green ones after one 10 min drive )
after a few miles on the car they would fit your description... even had one that crumbled completely

I then switched to ford's own pads - the difference is unreal, and they last much much longer too...

but even better yet is the mintex OE spec pads (not as fancy as 1114's - sold by my local ford dealer) - they have even better feel and last just as long for a couple £ less




[Edited on 7/8/2013 by mcerd1]

[Edited on 7/8/2013 by mcerd1]

pewe - 7/8/13 at 11:30 AM

Same with my tin-top (SAAB 9-5) though I must admit I'd put it down to driving the "other" car which has braided lines and Mintex 1144 pads and stops like you've thrown out the anchor.
In fairness there is a substantial weight difference but having nearly rear-ended some-one recently (I know should drive within a safe stopping distance but we've all got that wrong at some point!).
I'm seriously thinking of changing the front pads.
IIRC the last lot were Pagid so I'm a bit surpriesd as they've always been adequate in the past.
Cheers, Pewe10

coyoteboy - 7/8/13 at 12:22 PM

I've had massively varying pad life across makes all on the same car (quick tin top), the best trade-offs I've found were Pagids on grooved rotors. Keep the glazing cleared when you overheat them but I do use a set every 10K road miles, roughly. But I use a set of tyres every 10K road miles too on that car. New versus old, as mentioned above, often affects the high temp performance a lot, but the cold bite (after bedding) is rarely different.

[Edited on 7/8/13 by coyoteboy]