My wear indicator light has come on for my front brakes and I wanted to check the disc thickness to see if I needed new discs at the same time as the pads.

When I look at the L405 workshop manual it tells me the discs were 34mm when new but doesn't say what the minimum thickness should be, only that it is marked on the disc (helpful - not!)

Anybody know what the minimum thickness should be? I have the high performance brakes with 6-pot calipers.

Cheers

Rob 2021 D350 Fifty Edition
2017 4.4 SDV8 Autobiography -
2012 4.4 TDV8 Westminster - Gone, but not forgotten

You are allowed 2mm wear, so if yours were 34mm new, you are allowed 32mm.

380mm front brakes
Front 380mm ventilated 34mm max wear 32mm
Rear 365mm ventilated 25mm max wear 23mm

363mm front brakes
Front 363mm ventilated 33mm max wear 31mm
rear 350mm ventilated 25mm max wear 23mm

349mm front brakes
front 349mm ventilated 34mm max wear 32mm
rear 325mm ventilated 25mm -max wear 23mm 2018 SE SDV8 4.4 Byron Blue

Thanks

Do they measure disc thickness on an MOT? 2021 D350 Fifty Edition
2017 4.4 SDV8 Autobiography -
2012 4.4 TDV8 Westminster - Gone, but not forgotten

I dont know, they will test the brakes if they pass, they pass but if your pad thickness alarm is on thats another matter  2018 SE SDV8 4.4 Byron Blue

But the dealers are keen to check it for you for obvious reasons  2018 SE SDV8 4.4 Byron Blue

Minimum disc thickness for the front is 31mm
Minimum disc thickness for the rear is 22mm

So maximum wear of 3mm is permissible.

That's according to the Delphi and Brembo spec sheets...

For MY18 JLR spec

https://www.fullfatrr.com/gallery/albums/u...0Specs.pdf

But in the 2016 WS manual it doesn't actually give the wear spec but it does say its marked on the discs somewhere. 2018 SE SDV8 4.4 Byron Blue

Yes, it's marked on the outside edge  Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

Thanks all.

Mine's a MY17 (67plate) but does seem like the consensus is that 31mm is the minimum.

 2021 D350 Fifty Edition
2017 4.4 SDV8 Autobiography -
2012 4.4 TDV8 Westminster - Gone, but not forgotten