Braking issue

[D4dawg]

Well apologies if I've offended you, but if you haven't actually had experience with the issue then I see little point in posting statements regurgitated from elsewhere. In this case yes, fitting 2nd hand pads isn't ideal but unless someone can enlighten me further I can't see how it could contribute to uneven brake force once bedded in properly. Far more likely as others have said to be an issue with the bleeding on one of the calipers or also a sticky slider, but that one would be some coincidence to occur just when you've changed pads.
I might be totally wrong though OP let us know how you get on!

By the way the Pagids are extremely hard, not soft

It's all good buddy
Used to try it when a student on my 205 gti and found it just didn't like it haha

N yeah got ds2500 pads on mine and new waiting for new calipers to be fitted and are silly hard meant that not soft got pad wears wrong way round:)

[Ewazix]

Can anyone actually explain to me with some degree of actual science why using part worn pads is a bad thing, not just they won't mate with the disk nonsense?

It's rare to find pads wearing evenly on all areas and normal for some degree of wedge or tapering to develop so as you can imagine a different brake set-up may not apply some areas of the pad, leading to uneven braking or squealing. But providing the pads and discs are in good shape I'd have called it a cheapskate pikey tight-wad move, rather than a killer

This is a nice write up on diagnosing brake issues from the pad wear
http://www.knowyourparts.com/technical- ... ear-chart/

[TomK]

Can anyone actually explain to me with some degree of actual science why using part worn pads is a bad thing, not just they won't mate with the disk nonsense?

It's rare to find pads wearing evenly on all areas and normal for some degree of wedge or tapering to develop so as you can imagine a different brake set-up may not apply some areas of the pad, leading to uneven braking or squealing. But providing the pads and discs are in good shape I'd have called it a cheapskate pikey tight-wad move, rather than a killer

This is a nice write up on diagnosing brake issues from the pad wear
http://www.knowyourparts.com/technical- ... ear-chart/

Yes I would totally agree that at the beginning of installation of pads from a different disc/installation source there may well be slight differences in braking capability between the left and right side.
When I installed these 2nd hand pads you could see that it took time for the pads to wear off the 'uneven' surfaces by the deposits on the disc. However even during this phase (it doesn't take long for the pad to wear correctly to the disc) i did not notice any pulling to either side.

It is pretty cheap skate I agree! In my case though the rare opportunity of finding a bunch of RS-29s in good condition lead me to trying them, economically and performance wise I'm happy I did in the end.

[Viren]

I bedded the pads in twice yesterday and after a long drive today the pulling to the left is no longer there, seems like the issue could have been mating the pads with the disc which takes a little longer given they were used.

BTW I went to silverstone today and did a 30min track session, the pads felt great, pretty much the same as the existing ones. I know there's been a lot of discussion but going by my experience seems OK to me provided they are properly bed in. I will be changing brake pads and discs soon as mentioned earlier, this was only meant to be a temporary thing.

[D4dawg]

Sounds good:)

If wait for a couple more weeks
I'm selling all my discs calipers and ds2500 pads with just 2k use on pads

As replaced the lot with bbk;)

[Lower]

Well apologies if I've offended you, but if you haven't actually had experience with the issue then I see little point in posting statements regurgitated from elsewhere. In this case yes, fitting 2nd hand pads isn't ideal but unless someone can enlighten me further I can't see how it could contribute to uneven brake force once bedded in properly. Far more likely as others have said to be an issue with the bleeding on one of the calipers or also a sticky slider, but that one would be some coincidence to occur just when you've changed pads.
I might be totally wrong though OP let us know how you get on!

By the way the Pagids are extremely hard, not soft

Discs tend not to wear consistently. They will be concave, convex, have grooves etc and pads wear to that shape. So if you take pads that gave already bedded to the shape of an existing set of discs and then put them on a different set of discs you 'may' have issued with uneven braking initially as the amount of pad contact from one side of the car to the other will be different.

They should in theory wear in and end up matching the shape of the new disc, but there is the risk of the pad twisting and jamming in the calliper during this process. It's happened to me when I've swapped between track pads and road pads. You may get away with it but you may not.

As I mentioned before, I think the op's problem us probably related to bleeding, but fitting worn pads is always risky.

[Viren]

Sounds good:)

If wait for a couple more weeks
I'm selling all my discs calipers and ds2500 pads with just 2k use on pads

As replaced the lot with bbk;)

Interested......

[Viren]

Well apologies if I've offended you, but if you haven't actually had experience with the issue then I see little point in posting statements regurgitated from elsewhere. In this case yes, fitting 2nd hand pads isn't ideal but unless someone can enlighten me further I can't see how it could contribute to uneven brake force once bedded in properly. Far more likely as others have said to be an issue with the bleeding on one of the calipers or also a sticky slider, but that one would be some coincidence to occur just when you've changed pads.
I might be totally wrong though OP let us know how you get on!

By the way the Pagids are extremely hard, not soft

Discs tend not to wear consistently. They will be concave, convex, have grooves etc and pads wear to that shape. So if you take pads that gave already bedded to the shape of an existing set of discs and then put them on a different set of discs you 'may' have issued with uneven braking initially as the amount of pad contact from one side of the car to the other will be different.

They should in theory wear in and end up matching the shape of the new disc, but there is the risk of the pad twisting and jamming in the calliper during this process. It's happened to me when I've swapped between track pads and road pads. You may get away with it but you may not.

As I mentioned before, I think the op's problem us probably related to bleeding, but fitting worn pads is always risky.

I don't think the problem was related to bleeding as the problem was there before bleeding. I changed pads, felt the pull, bled the brakes, the pull remained. Only today did it disappear after properly bedding the brakes in. I think it may be as you said that the pads had shaped to another set of discs and needed to mate with the 'new' discs.

[ronk]

The donor pads will have worm /bedded in on the discs with their own signature ridges etc - when applied to another disc the surface areas of the pad on each side of the disk will be different - uneven brake force should be expected. It not good practice to do this.

[Viren]

The donor pads will have worm /bedded in on the discs with their own signature ridges etc - when applied to another disc the surface areas of the pad on each side of the disk will be different - uneven brake force should be expected. It not good practice to do this.

After some time won't this even out so the pads mate with the discs? There was definitely uneven force hence the pulling effect but this did go after 100 miles

[ronk]

Yes it will, but you have to be cautious as the ridges and hollows cause extreme hot spots until the pads bed in again.

[vester86]

Well apologies if I've offended you, but if you haven't actually had experience with the issue then I see little point in posting statements regurgitated from elsewhere. In this case yes, fitting 2nd hand pads isn't ideal but unless someone can enlighten me further I can't see how it could contribute to uneven brake force once bedded in properly. Far more likely as others have said to be an issue with the bleeding on one of the calipers or also a sticky slider, but that one would be some coincidence to occur just when you've changed pads.
I might be totally wrong though OP let us know how you get on!

By the way the Pagids are extremely hard, not soft

Discs tend not to wear consistently. They will be concave, convex, have grooves etc and pads wear to that shape. So if you take pads that gave already bedded to the shape of an existing set of discs and then put them on a different set of discs you 'may' have issued with uneven braking initially as the amount of pad contact from one side of the car to the other will be different.

They should in theory wear in and end up matching the shape of the new disc, but there is the risk of the pad twisting and jamming in the calliper during this process. It's happened to me when I've swapped between track pads and road pads. You may get away with it but you may not.

As I mentioned before, I think the op's problem us probably related to bleeding, but fitting worn pads is always risky.

I don't think the problem was related to bleeding as the problem was there before bleeding. I changed pads, felt the pull, bled the brakes, the pull remained. Only today did it disappear after properly bedding the brakes in. I think it may be as you said that the pads had shaped to another set of discs and needed to mate with the 'new' discs.

again, i think you have to overhaul your brakes, especially the sliding pins & bushes! especially because the problem existed before the change of pads.....

[Viren]

The problem did NOT exist before the change of pads. The sliding pins are clean and working as they should and no sticking calipers. The pull to the left was a direct result of the used pads, however as mentioned this has now disappeared given they appear to have bedded in and now both sides have a clean connection with the discs. Not saying it's ideal and it's only a temporary one month type solution as I will be replacing discs and pads soon. BUT the braking does seem to be as good as it was with the previous pads.

[Fishy Dave]

The donor pads will have worm /bedded in on the discs with their own signature ridges etc - when applied to another disc the surface areas of the pad on each side of the disk will be different - uneven brake force should be expected. It not good practice to do this.

Agreed, not best practice. But, had the OP fitted brand new (flat) pads with a used disc (with grooves/slight lip) he may have experienced the same issue. Call me tight but I wouldn't automatically replace a good, safe disc at the same time as a pad change. As mentioned, if mating one or two used parts together you just have to expect uneven brake force for a short time.
When Tom bought his bargain part worn RS29s we were potentially going to go halves, but I chose the different path of buying new EBC Bluestuff. I'd say we were both happy with the braking performance on both cars.
As mentioned above I'd be more concerned about the 8mm caliper spacing, I spaced my M3 AP kit by 2mm though and have been fine though.

[Easty-5]

I can concur with both Tom and Dave. I haven't bought second hand pads for the Z but I did buy a job lot of used DS2500 pads for my Clio 182 a few years back. 6 sets in total, all about half worn. I got through 3 sets and never once did I have an issue. 5 or 6 HARD stops and they were absolutely perfect.

As Dave mentioned, if you think that 2nd hand pads won't bed to the current condition of your disks, then the same theory must be applied to putting new pads onto part worn disks, and we all know, very rarely do we always change disks at the same time as the pads.

There are loads of opinions getting thrown around on this thread but very little actual facts and previous experiences.