Mysterious Wear to Brake Discs

This is the Forum for all your Peugeot Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
User avatar
Pug_XUD_KeenAmateur
(Donor 2018)
Posts: 1168
Joined: 22 Apr 2013, 17:24
Location: South Midlands / M4 / M5
My Cars: 405 naD Est
x 232

Mysterious Wear to Brake Discs

Post by Pug_XUD_KeenAmateur »

Any ideas how this has happened?
Brake 1.jpg

Brake 2.jpg
Brake 2b.jpg
Needless to say Discs & Pads have been replaced, 49k old (Jun 2015) Pagid & Bosch respectively.

That pad is the 'correct' pad from that side of that caliper.

That Brake was found to be dragging a bit: a clean up of the Piston has resolved that; can't see that being relevant though.

When New
Brake 3.jpg
Puxa
RichardW
Forum Treasurer
Posts: 10889
Joined: 07 Aug 2002, 17:12
Location: United Kingdom
My Cars: MK2 '17 C4GP 1.6 BlueHDi 120
'13 3008 1.6 HDi GripControl
x 1002

Re: Mysterious Wear to Brake Discs

Post by RichardW »

Pug_XUD_KeenAmateur wrote: 28 Mar 2019, 13:38


Image


Looks like the pads are a little undersized and have left a rim at the edge unswept which has then grown and worn into the pads. Just one of those things.... doing well to have got 50k out of a set of pads!
Richard W
User avatar
Skull
Donor 2024
Posts: 946
Joined: 02 Aug 2013, 13:35
Location: Darlington Co Durham
My Cars: Citroën Xantia XII HDi
Citroën sAXo XII

Missing AX 1.4D Echo
x 225

Re: Mysterious Wear to Brake Discs

Post by Skull »

It's always puzzled me why pads don't extend to the full diameter of the disc and it seems acceptable to have that lip build up - is it just to show visually how much the disc has worn :?:

Your old pads seem to be a poor fit but I would still be using them :roll:
On my 4th Citroën Xantia (X2 HDi (110))
Citroën sAXo Memphis Mk II
Gone
Xantia x3 (2.0i TCT Activa)(2.1 TD SX)(1.9 TD Estate)
Xsara HDi VTR Coupe / Saxo 1.1i / BX 1.9 d / 4 x AX's (1.4D /1.5D)
2 x 406 (1.9 TD Estate/2.1 TD Saloon) 405 1.9 D Estate 306 1.9 XTDT Hatch
User avatar
white exec
Moderating Team
Posts: 7445
Joined: 21 Dec 2015, 12:46
Location: Sayalonga, Malaga, Spain
My Cars: 1996 XM 2.5TD Exclusive hatch RHD
1992 BX19D Millesime hatch LHD
previously 1989 BX19RD, 1998 ZX 1.9D auto, 2001 Xantia 1.8i auto
and lots of Rovers before that: 1935 Ten, 1947 Sixteen, 1960 P5 3-litre, 1966 P6 2000, 1972 P6 2000TC, and 1975 P6B 3500S
x 1752

Re: Mysterious Wear to Brake Discs

Post by white exec »

Not unusual wear on discs that have done a lot of work.
Normal disc wear takes place on the swept area, and the outer edge of the disc (a) remains unworn, and (b) rusts and swells. The lip just wears a groove into the pad outer edge, especially if replacement pads are slightly wider than those previously used.
Chris
User avatar
moizeau
Donor 2024
Posts: 1589
Joined: 12 Jan 2015, 16:08
Location: France 36
My Cars: 91 BX TZD Estate. Dead but loved
407 HDI 136 auto
C4 2l petrol coupé
2010 Dispatch III HDI 90
AND a 1980 Z1000ST
AND a 1983 GPz1100 inj
AND a 1995 Zephyr 1100
AND a 1980 Z650 (my moped)
x 315

Re: Mysterious Wear to Brake Discs

Post by moizeau »

Agree with everything mentioned above, it's normal. If you then measure thickness of the swept area and it is within the limits take an angle grinder to the lip.
Pete
Notice the BX is still top the list but sadly gone
User avatar
Pug_XUD_KeenAmateur
(Donor 2018)
Posts: 1168
Joined: 22 Apr 2013, 17:24
Location: South Midlands / M4 / M5
My Cars: 405 naD Est
x 232

Re: Mysterious Wear to Brake Discs

Post by Pug_XUD_KeenAmateur »

thanks Guys, not ideal that I've gone to the bother to change the Pads & Discs; but glad the puzzle's solved :-D

I was under there to confirm to myself whether the 'Knock' is the Bottom Engine Mount (it is, and it'll keep) and noticed this. Long trip to hilly Devon 3 up next week, so got it sorted toute suite; fronts 'll have a bit of a 'holiday' coz I'll have peeps in the back, but all the same. ...and you never know when someone's gonna do something stupid; methinks running an older high mileage car its obligatory to be extra careful with safety matters.

I think one of the advantages of Diesels Richard is that you don't actually need the brakes much, in most situations, hence the healthy mileage on the pads. I noticed driving Daughter's petrol 1.1 C3 the evening mine was out of action how much more you use 'em. Mostly I just ease off the throttle and the engine compression takes care of it (not one for coming down the gears, my Driving Instructor always said 'Brakes are Cheaper than Clutches'; 1987, makes me feel old!).

NB: quite impressed with the new TRW Brand Brake Pads, which included a new set of Caliper mounting bolts (the little 13's), each Loctite'd. My Factors told me they're top quality and I was a bit doubtful, but they were all I could readily get; seems that's worked out well.
Puxa
Post Reply