Xantia brakes

Toby_HDi · Post by **Toby_HDi** » 03 Mar 2009, 21:13

Once my Xantia has had its steering rack gaiter done I am going to do the brake hoses and brakes and hopefully get it through the MOT.

About to buy the parts from GSF along with some copperslip. A slightly silly question perhaps but which components exactly require the copperslip?

I do not have any flare nut spanners, would normal spanners be adaquate for the unions? Also, what do people use to clean up caliper corrosion? I'm assuming a wire brush but is anything else recommended? What kind of material should I think about for a gasket for the mouting faces to prevent further corrosion?

Xaccers · Post by **Xaccers** » 03 Mar 2009, 23:16

for the corrosion, I've used a lump hammer and a sharpish pry bar or a chisel.
it's like limescale buildup

Post by **RichardW** » 04 Mar 2009, 08:10

Toby,

Are you thinking front and rear, or just fronts - IIRC MOT was fronts only?

Copperslip goes on the edges of the pads where they slide in the caliper, and on the back of the pads where the caliper / piston bears on them. take care not to get it on the friction surface! I also like to put a thin (and I do mean thin!) smear on the hub before refitting the disc to help it come off next time, and I also grease the caliper slide pin. Make sure you clean the disc with meths or brake cleaner once it is fitted, and before you fit the pads.

For the fronts you will need a T55 socket to get the caliper bolts out, and a smaller one (T25 maybe?) to extract the disc retaining screws. Don't forget on the fronts to wind the piston back in (clockwise) rather than just push it. Getting the pads out of the HDi 110 front brakes is a bit of a challenge due to the anti rattle spring - drift them out with a wide bladed chisel or something. If you're going to the hassle of doing most of the front brakes, you might be as well to do the h/brake cables as well - remember though that GSF do not sell the longer N/S cable required for the HDi 110. At the least unclip and pull back the cable before trying to swivel the caliper - it makes life much easier.

A brake pipe spanner (8mm probably) would be preferred for the pipe union on the front pipes (and the rears if you are doing them). I couldn't get an 8mm 'open' brake pipe spanner, so had to buy a closed one and saw a chunk out of it.

If you are tackling the rears as well, be very very gentle with the caliper bolts - they can and do break, and cause all sorts of hassle. At the rear, remove the small bolt and pads, then refit the bolt BEFORE removing the main bolts - this stops the caliper falling apart. Corrosion is easily removed by filing or similar once the caliper is off. Make sure the pads are a nice loose fit in the rear calipers, and copperslip them all the way around the metal backing.

At least bleeding is easy - start engine, wedge break pedal down, open bleed screw and sit back (although getting to the bleed screws on the fronts is a bit tricky - need to have the handbrake cables out)! When doing the rears, bleed plenty through - the air can take some time to make it through.

citronut · Post by **citronut** » 04 Mar 2009, 09:04

the flexi hose pipe nut calliper end is 14mm, and yes for that end an open ended spanner is fine

you should always disconect the hand brake cables before windding the pistons back, and dont re/conect it till you have started the engine and pressed hard on the brake pedle 2 to 3 times, this resets the calliper adjustment and pads,

regards malcolm

Toby_HDi · Post by **Toby_HDi** » 04 Mar 2009, 11:11

Thanks for the help fellas.

Yes I will be doing both. The MOT failure was fronts but I was going to do them all come next payday anyway.

Are standard spanners ok for the front hose unions? As I have to replace the hoses too.

I assume the handbrake cable is not too bad a job?

Indeed, I've had many a surprised face from others when I've bled the Xantia in the past

Discs, Pads, Hoses, Copperslip and brake cleaner all on the way

Post by **CitroJim** » 04 Mar 2009, 13:09

Front hoses. the rigid pipe end is 10mm and a flare-nut spanner (ring with a cutout to slip over the pipe) is a good idea to get it started and then it can be undone the rest of the way with an open-ender.

On the claiper end of the flexi, I normally chop the pipe off (you're replacing it anyway) and then I can slip a normal 14mm ring spanner onto the union hex. An OE spanner will often round off the union hex.

Hardbrake cables are a walk in the park by Xantia standards Toby

They look diabolical but are just the opposite. It is very important to keep the cables in the guide rings (so easy to miss one) and to not that handbrake cables are sided. Your 110 HDi uses the "long" LH cable not stocked by GSF.

Post by **RichardW** » 04 Mar 2009, 16:22

Xantia handbrake should hold well at 2 clicks. If it needs to come up near vertical, then there's something wrong with one or both of the cables, or the adjusters in the front brakes.

Toby_HDi · Post by **Toby_HDi** » 05 Mar 2009, 14:56

Just to confirm:

I need an 8mm AND a 14mm Flare nut spanner? I have not one of these so will need to buy one (possibly a set I'm thinking)

Thanks

SLYTZD · Post by **SLYTZD** » 29 Mar 2009, 23:07

Yes there was a recall. I believe the first 4 teeth were removed because like you say, people were applying the handbrake lightly & as the hot discs contracted when they cooled the handbrake failed to hold the car.

According to Haynes when adjusted correctly the handbrake should be FULLY on at 1 or 2 clicks.

I have only really been able to adjust it down to that with new pads in. The front callipers should auto adjust (at 15 clicks I think?) I never found mine to work, maybe due to someone damaging them by not winding the pistons in when changing the pad.

Hand Brake at 1 click,

& at 2 clicks.

My pads & cables need replacing ASAP so this is where it really is.

Earlier in this thread oxidisation of the rear callipers was disgust. I recently change the rear pads on my Activa for the first time & noticed the old pads had worn unevenly. As I was pressed for time I just slapped the new pads in & expected in a day or to that they would bed in ok. Not so. After a couple of weeks I realised I was going to have to properly clean up the callipers as only about half the pad was in contact with the disc.

I had read that the back of the calliper can oxidise quite badly pushing it out of alignment but was still surprised when I found by how much & how much "scale" was actually there.

Not a great photo but you can see I've scraped half of it off, almost 1mm!

I used a spinning wire brush on mine.

The moral of the story is do the job right the first time but also, if you're replacing the pads & you haven't done so already, take the callipers off & give the back of them a good clean & apply copper grease because if they're not causing any problems yet, if you leave them they probably will.

Post by **admiral51** » 30 Mar 2009, 00:48

I had to replace both disks and pads on the rear of my 1.9TD this weekend due to MOT failure and i was aware of the oxidisation problem on the calipers

.Actually doing the job and seeing how bad the oxidisation was is a real eye opener

I tried to clean the caliper up first off with just a wire brush but on refitting the disk would not spin without catching the caliper it was that far out

It took a good few minutes using a flat file and wire brush on both caliper and mounting surface before the caliper would sit square on its mounting plate and allow the disk to pass cleanly

Colin

Toby_HDi · Post by **Toby_HDi** » 30 Mar 2009, 00:52

Hmmm, seems I have some fun and games when I get around to the rears.

Is there anything in particular that would make a good material for a gasket to prevent this corrosion? I'm thinking it may be worth popping something in there.

Post by **myglaren** » 30 Mar 2009, 01:05

some vinyl sheet - the stuff used for builders rubbish bags is ideal.

Post by **admiral51** » 30 Mar 2009, 01:06

Toby_HDi wrote:
Is there anything in particular that would make a good material for a gasket to prevent this corrosion? I'm thinking it may be worth popping something in there.

To be honest Toby it would have to be a very very thin gasket (sort of fag paper thin) as there really isnt a lot of tolerance to play with.Provided both surfaces are cleaned really well then you shouldnt have too many problems refitting its just that over time the corrosion builds up between the 2 mating surfaces and pushes the caliper out of true and you end up with pads worn wedge shaped

I put a bit of copper slick between the 2 surfaces but im not sure if this will stop/help or encourage the corrosion

Colin

addo · Post by **addo** » 30 Mar 2009, 03:55

I've found this a really useful thread, in terms of answering some questions about what the corrosion looks like. My rear calipers are hanging up somehow; there's a resonant "click" when they're applied or released.

We have no equivalent to GSF here, in terms of accessibility, so I'm keen to hear of there are any sacrificial parts involved when tearing down and reassembling. I plan to use Wurth copper grease, as it's rated to 1200°C before breaking down.

At least "Down Under" the moisture worries are far less!

Cheers, Adam.

vince · Post by **vince** » 31 Mar 2009, 22:40

One thing to bear in mind is using copper based grease around the braking system can in some cases cause ABS lights to come on. This is due to the metal content of the grease.

For this specific problem ceramic based grease such as Cera-tec has been developed and is slowly taking over.

I know GSF are giving free sachets of this stuff away with every set of pads purchased . If its not given when buying some....ask for it