Braking issue

[Viren]

I had changed out the front brake pads yesterday for some used ones (the used ones had a lot of life in them). Did a brake bleed as well.

Now when I brake at speed the car pulls to the left, only under Braking. When I fully depress the brake the pulling effect is less. Under medium pressure it's a stronger pull to the left.

Doesn't appear to be any brake binding as both wheels move freely. Any thoughts?

 

[srhutch]

Used pads will have worn to the disc they were used on which won't be the same as your's.

Fit new pads would be my suggestion.

 

[Lower]

I had changed out the front brake pads yesterday for some used ones (the used ones had a lot of life in them). Did a brake bleed as well.

Now when I brake at speed the car pulls to the left, only under Braking. When I fully depress the brake the pulling effect is less. Under medium pressure it's a stronger pull to the left.

Doesn't appear to be any brake binding as both wheels move freely. Any thoughts?

You've not bled them properly and you've still got air in the system.

Bleed them again.

Edit. Didn't see that you've fitted used pads. That will contribute to the problem. Fitting used pads is a bad idea.

 

[Anonymous]

As above
No matter how much is on old pads they will not bed on your discs

So time to cough up and but new pads

 

[Buckz]

Stop being so cheap and invest in some new pads.

 

[Viren]

Haha! Yes ok I will cough up

These were only meant to be temporary. However don't people switch between track and road pads on the same disc?

 

[TomK]

Haha! Yes ok I will cough up

These were only meant to be temporary. However don't people switch between track and road pads on the same disc?

Indeed they do without issue. I have been swapping pads quite often recently, got a load of part worn rs-29s. No issues with bedding them to the disc really, just need to stamp on them a few times. After 50 miles or so they are fine.
To say you can't use part worns is nonsense really.
I suspect more likely you need to rebleed, but give them a proper work out beforehand, it might be that.

 

[Lower]

Haha! Yes ok I will cough up

These were only meant to be temporary. However don't people switch between track and road pads on the same disc?

Indeed they do without issue. I have been swapping pads quite often recently, got a load of part worn rs-29s. No issues with bedding them to the disc really, just need to stamp on them a few times. After 50 miles or so they are fine.
To say you can't use part worns is nonsense really.
I suspect more likely you need to rebleed, but give them a proper work out beforehand, it might be that.

Sharing pads on the same discs isn't so bad. It's moving pads between different cars where the discs wear differently that can cause problems.

 

[Anonymous]

Haha! Yes ok I will cough up

These were only meant to be temporary. However don't people switch between track and road pads on the same disc?

Indeed they do without issue. I have been swapping pads quite often recently, got a load of part worn rs-29s. No issues with bedding them to the disc really, just need to stamp on them a few times. After 50 miles or so they are fine.
To say you can't use part worns is nonsense really.
I suspect more likely you need to rebleed, but give them a proper work out beforehand, it might be that.

Sharing pads on the same discs isn't so bad. It's moving pads between different cars where the discs wear differently that can cause problems.

Exactly not just random old pads
As no bedding in surface and will not mate with disc front properly, 2 sets of new pads both mated to same disc makes sence as wear evenly,
Road pads are cheap as chips if not performance, but id never use cheap pads, as fade etc
why do people buy performance cars and cut more corners than a fat kid running to a sweet shop

 

[TomK]

Indeed they do without issue. I have been swapping pads quite often recently, got a load of part worn rs-29s. No issues with bedding them to the disc really, just need to stamp on them a few times. After 50 miles or so they are fine.
To say you can't use part worns is nonsense really.
I suspect more likely you need to rebleed, but give them a proper work out beforehand, it might be that.

Sharing pads on the same discs isn't so bad. It's moving pads between different cars where the discs wear differently that can cause problems.

Exactly not just random old pads
As no bedding in surface and will not mate with disc front properly, 2 sets of new pads both mated to same disc makes sence as wear evenly,
Road pads are cheap as chips if not performance, but id never use cheap pads, as fade etc
why do people buy performance cars and cut more corners than a fat kid running to a sweet shop

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?
Even if the pads had worn unevenly side to side that wouldn't actually be an issue, as the pistons compensate for pad depth independently.
I wouldn't normally fit part worns I might add, however at £600 a set for RS-29s I came across 2 used probably half worn sets for £200. What the hell, I thought I would give them a try. Both sets of part worns have been as good as the brand new set I used originally.

 

[Anonymous]

So if don't " normally " fit them yourself
Why still bitching on about it?

 

[vester86]

Now when I brake at speed the car pulls to the left, only under Braking. When I fully depress the brake the pulling effect is less. Under medium pressure it's a stronger pull to the left.

sounds like sticky slide pins to me

 

[TomK]

So if don't " normally " fit them yourself
Why still bitching on about it?

Because, to actually try and help the OP pal. From having tried this twice now I can say with some degree of fact that using part worn pads is not going to make the car pull to one side. Have you any actual facts to add to this thread?

 

[Anonymous]

Perhaps the way you respond to others in posts may be the issue.
Love what you've done to your car but when others post a response your reply comes across as negative

You have done this to myself in other posts also hence my response
Probably a lovely gent in person but maybe read before post as can offend buddy

Ref pads the face of disc and the compound in hard pads can cause grooves and divots this matches that pad
When a soft race pad is used such as your pagids
They can wear and adjust to these marks keeping mating surface area at a maximum
So can use decent pads in theory with a few good stomps of pedal to bed them

 

[TomK]

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 :lol: OP let us know how you get on!

By the way the Pagids are extremely hard, not soft

 

[Anonymous]

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 :lol: 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 :wink:

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

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

 

[Anonymous]

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