Replace discs but not pads?

Diddums · 16 Sep 2017 at 13:15

The discs & pads on our Mini were replaced less than 4k miles ago. One of the discs for some odd reason has developed a small warp in it so the car shudders a bit under braking. Is it wise to replace the discs but not the pads? I've no issues doing both but if it's not really needed then I'll leave it.

Thoughts?

jigger · 16 Sep 2017 at 14:06

I wouldnt mess around and just change the lot.
The disc should still be under warranty so you should be able to get at least a 50% discount.

Diddums · 16 Sep 2017 at 14:27

Ja, my thoughts too. Will just do the lot, cheers

sigma · 16 Sep 2017 at 15:28

It'd be worth getting the calipers checked to see if one of them is seized. That might explain what's causing the 'warping'. Otherwise you might well find yourself in the same position in another 4k miles.

kaiowas · 16 Sep 2017 at 16:44

I do it on the race car but it's an odd scenario where the pads cost a lot more than the disks (Carbotec pads at about £180 a set and pattern disks are only £25-£30 each) so I'll throw new disks at it fairly regularly. Just replaced the disks today actually as the ones on there were starting to show some surface cracks.

On Holiday · 16 Sep 2017 at 17:08

Discs don't warp.

Dis86 · 16 Sep 2017 at 18:45

Plenty O'Toole said:
Discs don't warp.

Definitely do.

Kenai · 16 Sep 2017 at 18:51

Dis86 said:
Definitely do.

Seems to be hotly debated with popular opinion gradually drifting to the consensus that it's actually uneven deposition of pad material that causes vibration and it's incredibly rare to actually warp the disc itself, especially so on road cars.

On Holiday · 16 Sep 2017 at 21:49

Dis86 said:
Definitely do.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Dis86 · 16 Sep 2017 at 22:05

Plenty O'Toole said:
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Having seen warped discs first-hand, it happens.

Big Spender · 17 Sep 2017 at 03:10

Pefectly safe to change only one at a time. Realistically you should be able to get through 2 sets of pads per 1 set of discs.

silverblack · 17 Sep 2017 at 10:22

If there is plenty meat on them i would just fit them.Guy i know had a mate who worked in a Renault dealership who kept all the good pads taken off cars to fit his Megane.

jigger · 17 Sep 2017 at 22:12

silverblack said:
If there is plenty meat on them i would just fit them.Guy i know had a mate who worked in a Renault dealership who kept all the good pads taken off cars to fit his Megane.

I bet he wouldn't have kept pads from a car with a warped discs tho.

silverblack · 18 Sep 2017 at 00:13

Only kept the good ones but even ones off a warped disk will soon wear down flat.

NoNameNoNumber · 18 Sep 2017 at 00:21

kaiowas said:
I do it on the race car but it's an odd scenario where the pads cost a lot more than the disks (Carbotec pads at about £180 a set and pattern disks are only £25-£30 each) so I'll throw new disks at it fairly regularly. Just replaced the disks today actually as the ones on there were starting to show some surface cracks.

Carbotecs can certainly eat discs!

vanpeebles · 18 Sep 2017 at 07:50

Diddums said:
The discs & pads on our Mini were replaced less than 4k miles ago. One of the discs for some odd reason has developed a small warp in it so the car shudders a bit under braking. Is it wise to replace the discs but not the pads? I've no issues doing both but if it's not really needed then I'll leave it.

Thoughts?

That would suggest to me, that they replaced the pads but didn't clean the calipers properly. I bet the new pads are sat in grot.

lordrobs · 18 Sep 2017 at 12:00

silverblack said:
If there is plenty meat on them i would just fit them.Guy i know had a mate who worked in a Renault dealership who kept all the good pads taken off cars to fit his Megane.

Having only ever had a maximum of two sets of replacement pads on a car during my ownership that seems like a huge waste of effort!

silverblack · 18 Sep 2017 at 13:27

lordrobs said:
Having only ever had a maximum of two sets of replacement pads on a car during my ownership that seems like a huge waste of effort!

I know i always bought new as i only did around 5000 mies a year.But this guy was doing 25-30k a year so was going through everything quicker.

Diagro · 19 Sep 2017 at 08:31

My car was juddering under braking.
Turns out it was an oil filled wishbone bush that has leaked it's grease.

mrk · 19 Sep 2017 at 10:49

Plenty O'Toole said:
Discs don't warp.

They don't warp if the callipers are working fine, but a seized caliper will be applying constant heat to the disc, and at speed this will warp the disc the more you drive it. This is exactly what happened to one of my discs due to a seized caliper. The pad itself was fine of course.