Brake disc condition

[killsta]

So, it's time to replace my pads as they appear to be a little worn...

However the front discs appear to have a little scoring - what do you guys reckon to the condition of the discs? Will they be fine with a set of new pads? Thickness wise they're perfectly fine.





Hoping to get away with just pad replacement

[Ozzie Osmond]

Discs look fine.

[eltax91]

Snotter or something nice? No signs they are warped through the pedal feel are there?

To be honest, I've put pads on discs that were at least as badly scored as those, because I couldn't get the "made from chocolate" disc screws replaced as it was a bank holiday. It was my mates daily TDi Leon, he has done 30k on them no problem.

[Patrick Bateman]

They don't look bad.

[killsta]

This is a 2007 350Z - no sign of judder, brakes are perfectly fine when driven normally and hard. Just checked the pads randomly today and noticed they were past their best

[vrooom]

I dont get some people. they change pads but not disc. i alway change both doesnt matter what condition.

[sparks_E39]

vrooom said:

I dont get some people. they change pads but not disc. i alway change both doesnt matter what condition.

Thats a waste of money really, brake discs should easily last several pad changes and at least 40-50k. Theres no way I could afford brake discs every time I changed the pads, which last around 20k.

[MrTom]

vrooom said:

I dont get some people. they change pads but not disc. i alway change both doesnt matter what condition.

They wear at different rates, whats not to get?

[Patrick Bateman]

vrooom said:

I dont get some people. they change pads but not disc. i alway change both doesnt matter what condition.

I don't get that.

[R300will]

If there is no vibration and the discs have plenty of life in them and your braking performance is not effected in anyway by the scoring then by all means just replace the pads as there is obviously no effect and therefore no rational reason to replace them.

If this is not the case however and you can feel something odd under braking then i would definately consider replacing them. after all you don't know when you're really going to need them and when you do you want them to work well!

[Patrick Bateman]

'Doesn't matter what condition' is like being presented with all the facts about something then basing your decision on none of them.

[killsta]

If I only replace the pads - will the scoring be gradually reduced over time?

[R300will]

Sort of, as the disc is harder than the pads the disc will more than likely score a matching set of grooves into the pads. But as the non scored bits of pad gradually wear down the non scored bits of disc it should gradually get more level.

(edit): scratch that. No i don't think it will as the disc is harder so it will just wear the groove pattern into the pads. Braking shouldn't be affected though as peaks will appear in the pads that fit the troughs in the disc so there should still be contact across overall surface after bedding in.

Edited by R300will on Thursday 6th October 15:22

[killsta]

R300will said:

No as the disc is harder than the pads the disc will more than likely score a matching set of grooves into the pads.

fk it, I'll replace the front discs as well. How noticeable would cross drilled discs be (£20 more) if it's known to spend some time on a track?

[DanielJames]

killsta said:

fk it, I'll replace the front discs as well. How noticeable would cross drilled discs be (£20 more) if it's known to spend some time on a track?

They look cooler!

[killsta]

doogz said:

Drilled discs are a bad idea.

What make of discs are you looking at?

Was looking at Brembo discs with Ferodo pads

[R300will]

Cross drilled can be weaker if not done properly. I would hopefully assume brembo would know what they were doing, vented discs will still cool properly?

[jagnet]

Rather than replace them, if there's still plenty of depth to them, you could just get them skimmed. It'll take out the ridges and allow the new pads to make maximum contact with the discs from the off, avoiding the need to bed them in while they wear to the grooves. No point throwing them away if you don't need to.

[R300will]

jagnet said:

Rather than replace them, if there's still plenty of depth to them, you could just get them skimmed. It'll take out the ridges and allow the new pads to make maximum contact with the discs from the off, avoiding the need to bed them in while they wear to the grooves. No point throwing them away if you don't need to.

How much would that be?

[jagnet]

Off the top of my head ~£40. Certainly cheaper than buying new.

Edit:
Disc skimming in action. Garages with a brake lathe: map

Edited by jagnet on Thursday 6th October 15:34