Changing brake discs but not pads?

[aph202]

Hi,

I understand you can't change brake discs without changing pads (because of the bedding in process?). Does this still apply if the pads have only just been done - say about 2k miles ago?

Thanks,

Adrian.

[Superhoop]

Just reface the pads using emery paper on a flat surface, this will remove the azed pad surface and give a good flat surface to bed to the new discs

[redstu]

Superhoop said:

Just reface the pads using emery paper on a flat surface, this will remove the azed pad surface and give a good flat surface to bed to the new discs

^
I've done that without problems, and with older pads as well.
I think the garages always say this to cover themselves and make more profit. There will of course be times when it makes absolute sense.

[flemke]

If the discs need replacing because of excessive wear, the irregularity of their surface will be mirrored in surface irregularity of the pad. For some period, the interface will be incomplete.
Normally, this is not a problem. When you think about it, it is no different from the incompleteness when you changed to new pads and kept the partly-worn discs.

[GreigM]

you've been to kwik fit haven't you - they'd happily have you believe that you will immediately die unless new pads are put in...as said above, unless they're in really bad shape if you sand them down flat and then pay a bit of attention to bedding in they will be fine

[anonymous-user]

aph202 said:

Does this still apply if the pads have only just been done - say about 2k miles ago?

Begs the question how the discs got knackered in 2,000 miles yet the pads are OK.

[Eggman]

If the pads are only 2k old I don't think I'd hesitate to replace the disks alone (I'd glance at them and make a judgement, but it would be very surprising to need new ones after so few miles). I wouldn't muck about with refacing them either - just take it easy for the first couple of hundred miles as you normally would.

[aph202]

Thank you, this is all very helpful.

My original understanding may well have come from Kwik-Fit - good call.

[vimulator]

Brake pads are much cheaper than the rotors, and it takes time to get at them. You might as well replace them so there is no messing around.

[Ash 996 GT2]

A answers to this, but, and here goes.

1 Knackered pads on new discs, no
2 Knackered discs on new pads, no

new discs and new pads yes.

Can you use the old, 2k pads once discs worn in? Yes

So, new pads need to be bedded in, so do new discs.

This is where it all goes wrong for kwik fit, they don't know the rules.

So, bed new discs in with new pads, never old, once they are done, you can probably use the older pads dependant on condition.

We do this on the race car, and have done for years.

Edited by Ash 996 GT2 on Sunday 28th November 20:35