New discs required or not?

Titan · Post by **Titan** » Mon 02 Mar, 2009 20:28

I’ve read the various posts on changing pads and discs, in particular Mike F’s “how to” guides. My problem concerns RIDGES on the rear discs with corresponding grooved in the pads.

The pads are worn and will be replaced but do I need to change the discs as well? Mike’s article refers to grooves in the discs (eg caused by a trapped stone) but I have the opposite situation.

In physical terms the reduction in contact area will be small and clearly new pads will soon re-groove to match the disc profile but is this acceptable? There is plenty of thickness left in the discs.

What would you recommend – new discs and pads or just pads?

Thanks
Titan

Justin Time · Post by **Justin Time** » Mon 02 Mar, 2009 22:13

What difference in mm is there between the top of the lip and the brake pad contact surface? How many miles has the Z done on the discs currently, and how heavy are you with the braking? A close up pic of the worst affected disc could be helpful as well.

Gazza · Post by **Gazza** » Mon 02 Mar, 2009 22:47

As you say, the pads will bed in to the profile of the disc.

c_w · Post by **c_w** » Tue 03 Mar, 2009 10:09

For the cost of new discs (if you're doing them yourself) I would just get new discs and pads. Grooves on the rear are lest common that grooves on the front (but you should, in theory, never get them as the pad should always be flat and wear the disc evenly).

SpunkyM · Post by **SpunkyM** » Tue 03 Mar, 2009 13:19

It really does depend on just how severe it is. Light ridges and grooves are very common and won't noticeably affect braking performance. As said above - really need a pic to comment.

Mouldy · Post by **Mouldy** » Tue 03 Mar, 2009 14:08

Unless your discs are severely worn, ie there is a pronounced lip around the outer edge, badly corroded or warped, I would only replace the pads.

From my experience, it is normal for the disc to develop fine ridges around the braked area , which I believe is largely due to the type of material that is used now to manufacture the pads.

Malc

SpunkyM · Post by **SpunkyM** » Tue 03 Mar, 2009 16:14

Yes, it's the sintering in the pads that does it. Worse since asbestos was removed from the compounds.

Titan · Post by **Titan** » Tue 03 Mar, 2009 17:52

Thanks for all the replies Guys

I was going to post pics but the weather up here is not very conducive - glad we didn't remove the hard top last Saturday.....

On balance, I'll bow down to SpunkyM's scintillating sintering and opt for new discs

Cheers
Titan

zroadster.net

New discs required or not?

New discs required or not?

New Discs