Brake pads fell out (?) after installing new ones
Discussion
Had new rear pads fitted to my Cayman in a local workshop whom I’ve used many times before. Took the car to a Bedford trackday, I realised after 3 shortish sessions both rear brakes were now metal to metal. No sign of pad on either of them. Yes the workshop definitely did put new ones in…
I did push hard, like I tend to do on trackdays, and PTV (Porsche Torque Vectoring) was on meaning the car was probably using rear brakes a lot if I went into a corner too fast. Still, I drove no different than I had done many times before.
What could have happened? Discs are now probably due replacement, too, which will add to the expense…
I did push hard, like I tend to do on trackdays, and PTV (Porsche Torque Vectoring) was on meaning the car was probably using rear brakes a lot if I went into a corner too fast. Still, I drove no different than I had done many times before.
What could have happened? Discs are now probably due replacement, too, which will add to the expense…
normalbloke said:
It’s not unheard of for the friction material to detach from the backing plate ( if that’s what has happened) and can occur for various reasons. What brand were the pads?
Bit odd for it to happen on all four rear pads in such a short period of time though, assuming that's what the OP means! Must have been a manufacturing defect with the pads. kambites said:
Bit odd for it to happen on all four rear pads in such a short period of time though, assuming that's what the OP means! Must have been a manufacturing defect with the pads.
Not sure about all 4 because with visual inspection I only see 2, or what should be 2. Those are missing.Those were non-OEM pads. £55 for a set, rather than £110 or so for OEM. As trackdays are expensive in consumables (£500/trackday, on average, counting all in: tyres, brakes, oil, etc), I’ve been experimenting with different types. I tried OEM, then models more expensive than OEM (Pagid RSL29), now these ones.
Another possibility is that they simply wore from 12mm to zero in these 3x15min sessions, but I think unlikely? The shortest I ever took to go through a set of rear pads was 3 trackdays, and even then 3mm was left, so that’d make it 3mm of wear per trackday, or 0.5mm/session (assuming 6 sessions/TD). Here for these to wear completely in 3 sessions would imply 4mm of wear a session, or 8x the normal rate of wear. Even the worst brand wouldn’t be that much worse than OEM I guess?
Another possibility is that they simply wore from 12mm to zero in these 3x15min sessions, but I think unlikely? The shortest I ever took to go through a set of rear pads was 3 trackdays, and even then 3mm was left, so that’d make it 3mm of wear per trackday, or 0.5mm/session (assuming 6 sessions/TD). Here for these to wear completely in 3 sessions would imply 4mm of wear a session, or 8x the normal rate of wear. Even the worst brand wouldn’t be that much worse than OEM I guess?
Edited by px1980 on Monday 20th February 19:52
If the friction material has dropped off as a whole, the pedal would likely have gone straight to the floor each time one fell out til you pumped the pedal to take up the “slack”. Not something which would have gone unnoticed during a track day, that’s for sure. 
More likely they were just s
t pads which you’ve overheated and worn through.
More likely they were just s
t pads which you’ve overheated and worn through.px1980 said:
Even the worst brand wouldn’t be that much worse than OEM I guess?
Two questions,1. What make were they branded?
2. Where did you buy them?
Brake pads are amongst the most frequently counterfeited car parts. You can make them out of cardboard for 50p, stick them in a nicely printed box for 10p and then sell them to gullible punters for £50
Bizarre!
Crap pads & the track session has cooked the friction material to the degree its seperated from the backplate?
Pads Stolen?
Pads never put in?
I've seen pads fitted incorrectly that have caused them to work loose & come adrift but it takes a fair bit of thought to make such an arse of most pad fitment. Even if this were done / possible (doubt it) you would be hard pressed not to hear the deafening sound of the pads rattling about in the wheels before they left the scene.
Crap pads & the track session has cooked the friction material to the degree its seperated from the backplate?
Pads Stolen?
Pads never put in?
I've seen pads fitted incorrectly that have caused them to work loose & come adrift but it takes a fair bit of thought to make such an arse of most pad fitment. Even if this were done / possible (doubt it) you would be hard pressed not to hear the deafening sound of the pads rattling about in the wheels before they left the scene.
Back in the day brake friction material used to be machanically rivetted to the steel "brake shoe" or pad "backing plate". People would talk about their brakes being "worn down to the rivets" when they started to squeal.
Then fancy adhesives were developed and "bonded" brake linings became the thing. Quite literally, the friction material glued to the backing plate. Modern cars tend to have brake wear indicators because without rivets to warn you, once the friction material has gone, it's gone.
Black market brake pads tend to have lousy friction material and/or very poor bonding. You can guess the rest.
IMO friction products (brakes and clutches) should only be bought from main dealers or from the most reputable other outlets. In itself the branding on the box gives no reassurance at all - it could so easily be fake.
Then fancy adhesives were developed and "bonded" brake linings became the thing. Quite literally, the friction material glued to the backing plate. Modern cars tend to have brake wear indicators because without rivets to warn you, once the friction material has gone, it's gone.
Black market brake pads tend to have lousy friction material and/or very poor bonding. You can guess the rest.
IMO friction products (brakes and clutches) should only be bought from main dealers or from the most reputable other outlets. In itself the branding on the box gives no reassurance at all - it could so easily be fake.
I did once actually have a brake pad fall out at bedford before... did make for some interesting stopping. Luckily, clamping force of three calipers was enought to drive gingerly into bedford town centre.
£30 on the cheapest brake pads i could find, popped one in and carried on with our trackday.
No idea how it happened, hasnt happened since. But i try and carry spares with me now.
£30 on the cheapest brake pads i could find, popped one in and carried on with our trackday.
No idea how it happened, hasnt happened since. But i try and carry spares with me now.
Panamax said:
Two questions,
1. What make were they branded?
2. Where did you buy them?
Brake pads are amongst the most frequently counterfeited car parts. You can make them out of cardboard for 50p, stick them in a nicely printed box for 10p and then sell them to gullible punters for £50
Bought on design911, where I’d bought a lot of items before. So not ebay or FB marketplace etc if that’s what you’re getting at. Advertised brand was ABS. 1. What make were they branded?
2. Where did you buy them?
Brake pads are amongst the most frequently counterfeited car parts. You can make them out of cardboard for 50p, stick them in a nicely printed box for 10p and then sell them to gullible punters for £50
Dave. said:
Are the backing plates of the pads still there?
Yes. I assumed the friction material just fell out, I’ve seen it crack and fall off like that on a mate’s car. It did not seem likely to me that pads could just wear in less than half a trackday, which as I wrote above, would be 8x normal rate of wear. But maybe those were just really rubbish pads, or counterfeit ones, as other people suggested. Expensive lesson, although I will try with the supplier as it doesn’t sound right
px1980 said:
Even the worst brand wouldn’t be that much worse than OEM I guess?
Some brands can be complete and utter dung.This might be better than some Chinese crap
https://www.youtube.com/watch?v=4TyBqqXYR3c
In many respects, for a standard car, OEM parts can be hard to beat. They will be better quality than most aftermarket parts. Some competition pads should be better, but there will be pros/cons either way in terms of how they operate and behave.
I've had quite a few "race" pads from a variety of manufacturers fall apart on me. But never to the extent you're talking about here. There are always signs of degrading performance to make you aware.
Although that's normally fronts and a car with no fancy features.
It might be worth turning off any fancy stability features that might be applying rear brakes for the next trackday
px1980 said:
PTV (Porsche Torque Vectoring)
I'm not familiar with that system, but if it applies the brakes as hard as necessary to achieve the desired effect then it seems possible that the rear pads overheated and got applied harder and harder to compensate, leading to sudden very high pad wear as they fell apart from the excessive heat and load.The alternative explanations that the linings physically fell out without you noticing or all wore out simultaneously in three short sessions both seem unlikely.
As was said above, if the friction material "just fell off" you would have "lost the pedal" for a few brake pedal pushes until the backing plate then contacted the disc, so you would have noticed that happen.
You have used "poor quality" pads which were not up to the task & they have worn at a very high rate.
I have managed this with ebc before but not to that extent, so it isn't much of an unlikelihood.
IMHO much better pads are 100% worth the spend & actually save money.
My experience with previous TD car:
Various "lesser" TD/fast road pads I would use a set every track day at a cost of around £100/front set.
RS29/DS1.11 etc would cost around £280-320 & last a full year with plenty of meat still on the bone, saving me at least £500/year with several hours less labour/time under the car.
You have used "poor quality" pads which were not up to the task & they have worn at a very high rate.
I have managed this with ebc before but not to that extent, so it isn't much of an unlikelihood.
IMHO much better pads are 100% worth the spend & actually save money.
My experience with previous TD car:
Various "lesser" TD/fast road pads I would use a set every track day at a cost of around £100/front set.
RS29/DS1.11 etc would cost around £280-320 & last a full year with plenty of meat still on the bone, saving me at least £500/year with several hours less labour/time under the car.
E-bmw said:
As was said above, if the friction material "just fell off" you would have "lost the pedal" for a few brake pedal pushes until the backing plate then contacted the disc, so you would have noticed that happen.
You have used "poor quality" pads which were not up to the task & they have worn at a very high rate.
I have managed this with ebc before but not to that extent, so it isn't much of an unlikelihood.
IMHO much better pads are 100% worth the spend & actually save money.
My experience with previous TD car:
Various "lesser" TD/fast road pads I would use a set every track day at a cost of around £100/front set.
RS29/DS1.11 etc would cost around £280-320 & last a full year with plenty of meat still on the bone, saving me at least £500/year with several hours less labour/time under the car.
On RS29 and similar “race” pads. Those may not be road legal, and even if they are, a phone call to insurer would be required to disclose the “modification” from OEM spec. So some hassle and likely higher premiums, assuming the track car is also driven on public roads and needs to be insured for those. You have used "poor quality" pads which were not up to the task & they have worn at a very high rate.
I have managed this with ebc before but not to that extent, so it isn't much of an unlikelihood.
IMHO much better pads are 100% worth the spend & actually save money.
My experience with previous TD car:
Various "lesser" TD/fast road pads I would use a set every track day at a cost of around £100/front set.
RS29/DS1.11 etc would cost around £280-320 & last a full year with plenty of meat still on the bone, saving me at least £500/year with several hours less labour/time under the car.
Having written this, I now realise that these cheaper pads I’ve had may needed to be declared as modification, too! They are certainly not race pad quality, but a deviation from OEM spec nonetheless… There’s been another thread on PH recently about a user’s policy being voided, and claim rejected, for having PPF on the car, so I’m pretty sure insurers would take similarly harsh view about brake modifications…
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