C4 brake concerns

andmcit · Unread post by **andmcit** » 08 Dec 2008, 19:47

My sister, Caz owns her own 2004 C4 model HDi1.6 16v which is showing
40k miles and has full service maintenance from new. In the last week a
rumble on the rear brakes has caused my father concern about the brakes
whilst being a passenger (back seat driver!!) although the brakes haven't
felt that good of late causing enough concern for the wheels to be
removed by my brother in law for a looksee earlier.

The car can very likely show 40k miles on it's ORIGINAL brakes as the car
spends a lot of it's life on the motorway and Caz has been brought up by
using engine braking rather than piling on the beans and blasting the
brakes to weigh anchor!!

I'd been expecting the discs to have a mirror like almost machined on a
lathe face to them for the first change of pads in the ownership of the car
and there are signs of this being the case but in fact the wear faces of the
discs have noticeable radial serrations on them ALL and this just doesn't
seem right for a full main dealer serviced car from new that has no record
in it's history of any replacement brake/hub components. I'm not so much
worried about the rust though there may be some pitting:

front left:

front right:

back left:

back right:

The car is used every day and I'm at a loss to understand how they look
so iffy although the pads still seem to have some 'meat' left on them.
All I can see as explanation are the big open styled alloy wheels allowing
weather easier into the exposed discs.

The uneven/serrated wear doesn't seem right to the point where I would
recommend my sister asks for a thorough check over by Citroen and an
independent specialist as I'm wondering if a warranty claim needs to be
pursued; the cost or replacement discs is eye watering once the built in
wheel bearings and I'm led to understand integrated ABS sensor are
factored into the parts cost before the actual pads £££'s...

Do these actually show discs that aren't getting the full braking pressure
or are binding - I realise there is a wear lip on the discs which obviously
means there is wear to them!

What to you guys think - am I being a bit neurotic? I am thinking more
about my sister's safety than her bank balance here!! We're not talking
about a company car here, it's her own fully paid for and she loves it!!

Andrew

Unread post by **CitroJim** » 08 Dec 2008, 20:53

Those discs look just about due for replacement Andrew. Discs wear as fast as pads these days and be careful comparing brakes and discs on a hydraulic Cit with those conventionally operated, either performance-wise or disc appearance. Conventional brakes scare me these days...

Pad compounds now are very hard and it's not unusual to see big scores in the discs nowadays.

I'd be inclined to have new pads and discs fitted soonish Andrew. they really do look due.

Nutcase · Unread post by **Nutcase** » 09 Dec 2008, 17:18

Hi Andrew
The amount of wear and the scoring looks entirely normal to me for the age/mileage of the car, a factor of harder pads and softer discs now used since the asbestos ban!

More rust on the rear discs again seems fairly typical, and likely rust decay will kill most rear discs rather than 'wear'. I would expect the fronts to be rust free however - unless the car has been standing for a few days. Might be worth bleeding the brakes if they haven't been done recently, and also checking/regreasing the caliper slides. A bit of air in the system and/or your sister's very light use of the brakes may account for the appearance of the discs.

Personally I would measure the disc thicknesses and if they are still in spec I would leave them for a while longer (just check all is working properly) given the huge cost of changing! If, however, they are just plain discs I would change them as they are generally cheap and easy parts to change.

Regards,
Greg

Kowalski · Unread post by **Kowalski** » 20 Dec 2008, 21:02

The front discs don't look like anything other than standard discs, i.e. no integrated wheel bearing, held to the hub by two screws. The rear discs have no visible screws and the wheel bearing dust cover appears to push into the disc, i.e. I can't see a separate hub so they could be an integrated hub / bearing / disc.

As a rough rule of thumb, a set of discs will last for two sets of pads. On the Xantia I got about 40k miles out of a set of front pads and the rears last about twice that length (I say "about" because I haven't had to change them frequently enough to get an accurate picture).

You'll have to measure pad and disc thicknesses and compare them with the minimum specifications to work out how close to needing to change them you are, Its fairly normal for the discs to become a bit scored and unless its deep its nothing to worry about, if that is the cause of the noise you'd probably be best to change them.

andmcit · Unread post by **andmcit** » 20 Dec 2008, 21:11

Thank you all for your replies and thoughts on this - it's no further forward
than where we were discussing what best course needs to be taken next
and getting Christmas out of the way!

One important point that may factor very significantly on this whole
discussion is an incorrect fact on my part about the age of the car
- it is in fact a 2006 model I just missed this totally as the car
wears a cherished plate!!

We're all quite shocked at the wear for the age/miles and the scoring
wasn't expected!!

I'll be visting my sister's place over the Christmas break to have a closer
look myself and praying that my totally horrid lurgi from hell is a distant
memory by then!

Andrew

AndersDK · Unread post by **AndersDK** » 20 Dec 2008, 21:21

I must say these discs and pads looks completely normal to my standards.

I would have no concern letting them go on for another 10 Kmiles before a new inspection, considered they have delivered a good 40K service until now.

But I would certainly give the calipers a work-over ensuring the pistons & calipers are moving freely and not completely dry on surfaces.
That will ensure a continued even friction wear.

That "mirror" look you speak off I've not seen over the past 15 years or so, ever since we abandoned both the asbestos friction pads and the later carbon-like friction pads.
Like Jim points out the friction materials are much harder these days.
Even the smallest chipstone or sand trapped in the pads will stay there until worn out and make its own score mark on the disc.

niggle · Unread post by **niggle** » 20 Dec 2008, 22:07

AndersDK wrote:I must say these discs and pads looks completely normal to my standards.

I would have no concern letting them go on for another 10 Kmiles before a new inspection, considered they have delivered a good 40K service until now.

But I would certainly give the calipers a work-over ensuring the pistons & calipers are moving freely and not completely dry on surfaces.
That will ensure a continued even friction wear.

That "mirror" look you speak off I've not seen over the past 15 years or so, ever since we abandoned both the asbestos friction pads and the later carbon-like friction pads.
Like Jim points out the friction materials are much harder these days.
Even the smallest chipstone or sand trapped in the pads will stay there until worn out and make its own score mark on the disc.

I totally agree with all the above, they look pretty much like the front discs do on my Berlingo at 41000 miles and also what my wife's previous Mini One D's looked like at that mileage: as long as they are within the wear limit they are fine.