Simon's new Xantia V6 and Leaf blog

[white exec]

Clean up the hubs, then lightly smear the back of the new discs with copper grease.
Tighten the discs down with wheel nuts/studs, but no wheel, then check the new discs for run-out with a dial micrometer. Particularly important for the fronts, which do most of the work. If run-out is too much, rotate the disc one hole and try again.

[Mandrake]

That's the discs and pads arrived yesterday and they are Bosch and look good.

You need a 5.5mm socket / spanner to get the disc retaining bolt out (no idea why it's that size!!); and when I tried on my HDi, the rear discs were firmly stuck to the hubs, so you may need to get medieval to get the old discs off!!

I'm confused - I thought the disc retaining screw was either a torx or Phillips countersunk screw ??

Remember this is a hatchback not an Estate like yours was - the rear brakes and suspension differ I think!

[RichardW]

Same estate / hatch - on the rear the disc retaining bolt also forms the pin that sticks out to allow you put the wheel back on without the hub just spinning helplessly and annoying you!! The estate has larger discs / calipers / caliper bolts, but the disc securing screw is the same.

viewtopic.php?t=24717

[Mandrake]

Same estate / hatch - on the rear the disc retaining bolt also forms the pin that sticks out to allow you put the wheel back on without the hub just spinning helplessly and annoying you!! The estate has larger discs / calipers / caliper bolts, but the disc securing screw is the same.

You're right Richard, and as it turns out the disc retaining bolts were more trouble than the caliper bolts! But I'm getting ahead of myself.

I fitted the discs and pads today and and it turned out to be a long and exhausting job - not helped by just coming off two weeks with a cold followed by a nasty chest infection that had really hit me hard... Either that or I'm just getting old and/or unfit!

In the end I didn't buy any caliper bolts so I took it carefully. I wire brushed the end of the thread and plenty of LPS1 spray. Three came out willingly, one felt like it was on the verge of yielding rather than unscrewing however patently working it back and forth many times a small amount finally got it free - probably the factory locktite being broken up. Bolts were in perfect order so a quick wire brush and grease and they were ready for reuse. So I made the right call (or got lucky) on the bolts...

I thought I would get away with using an in between imperial size socket on the 5.5mm retaining bolt since I don't have a 5.5mm but nope, it just started to round it off! In the end I hammered an E8 "reverse torx" socket onto it and it worked a treat. It goes on with some moderate tapping with a hammer and fits snugly with no play at all and can be pulled off with a pair of adjustable pliers.

The left caliper was in fairly good order but I hit a snag with the right one:

Interestingly the calipers were not out of alignment as is common on old Xantia's - they were still nice and parallel. And contrary to just building up corrosion that pushes them apart what had happened here is that a big chunk of the alloy from the caliper has ripped off the caliper and remained on the steel backing plate on the arm. So there was actually a dish shaped recess on the caliper below the level of the bolt holes of 1-2mm...

I realised if I scrapped all the alloy off the steel backing plate there was no chance the caliper would fit back on square, so I thought I'd try and put it back as-is - but no go - it wouldn't sit flush and with the thickness of the new disc the calipers were touching the disc. Damn.

The alloy of the caliper was so badly eaten away I thought my only option was to swap the calipers between the left and right side of the car to put the good uncorroded faces up against the backing plates. This is something that people on here say they have done before, but I also remembered that when Richard and I tried to do this on the Silver problem child we discovered that the hole used for the bleed screw has a taper seat in it while the one for the pipe does not! Hmm...

I was desperate though without a lot of other options so I cleaned and prepared the calipers and tried the bleed screw in its new hole and that's when I made a discovery - it does work! In fact all you have to do is fit the bleed screw in the new hole that previously had a pipe and nip it up moderately tightly with a small spanner and it makes it's own taper seat in the hole! In fact after doing this the tapered seat is visually identical to the original one.

So my conclusion is that the left and right parts are the same from the factory and that tightening up the steel bleed screw the first time is what creates the tapered seat in the alloy housing, not some extra machining step. So I scraped the backing plates clean, greased them with copper slip and fitted the calipers swapped over with the good sides to the backing plate.

To jump to the end of the story the bleed screws work perfectly and don't leak, and the pipes despite now having a slight taper in their holes that they didn't have before also work properly and seal perfectly. Not surprising when some union holes elsewhere in the car do have tapers already. So if you ever find yourself with a mess of corrosion to deal with you CAN swap the calipers from the left and right side of the car! As soon as you use the bleed screw it will make it's own taper.

I didn't know what torque to use on the caliper bolts - I ended up doing it by feel and according to my torque wrench I used about 80 Nm. Does anyone have any idea what the correct torque is ? I can always re-torque them if it's too high or low.

On reassembly I had my next snag - I snapped one of the disc retaining bolts off in the hole as it had started to get tight in the hole when it had come out perfectly easily. Argh! I started drilling out the snapped off bolt and only at that point did I notice that while the disc only has one retaining bolt hole the hub has two on opposite sides and I had not noticed!! So I think what happened is I tried to fit the bolt into the hole that was not previously used, which was probably rusted part way through thus the bolt got quickly tight at one point and snapped relatively easy. Bugger. Despite only having a few turns of thread left I found I was still able to reuse it. Phew!

So everything went back together and off for a test drive to bed the brakes in. It took quite a while even though I'd thrown some heavy load in the back to bias the braking more towards the rear but it did eventually start biting nicely. At about that time I started to notice a smell of burning oil! Oh crap. So I crept back home and discovered this:

The whole sump tray of the engine was completely covered in oil and it had splashed onto the exhaust as well, hence the smell. It actually looked like the oil was leaking from the front of the oil filter.... no that can't be. Granted there were some bubbles in the paint but surely it wasn't that ? So I cleaned it up and scratched some of the bubbling paint loose and started the car to have a look underneath. Nothing at idle but rev the motor up a bit:



Blimmin heck!! It was leaking through the front of the filter, and a lot. I have NEVER seen this in coming up on 28 years of driving and working on old cars... Who ever heard of an oil filter - you know, full of oil, rusting out from the inside until it leaks ??? Certainly not me. The paint was bubbled but not broken through until I scratched it off, so it definitely rusted from the inside.

The worrying thing is that we were planning to drive to the beach in Ayr tomorrow, if I had not done the brakes today and then gone for a test drive and smelt oil we would have driven it all that way with an oil leak and quite possibly done in the engine because I don't know if the Xantia has a low oil light on the dashboard...

The irony is that I was going to order oil/filter and coolant at the same time as the discs and pads but as I was juggling money with other needs and time was short I decided that I'd just do what was needed for the MOT and wait until after I got the MOT and didn't need to spend any more for the MOT and then do the maintenance items like oil/filter change. But now it will be off the road for a week while I order the parts and then find time next weekend to do the job. That's some degreasing job too, the underneath or the motor is completely soaked and it has got onto the exhaust pipe and lower engine mount as well...

So I guess we're going to the beach tomorrow in the Ion! It's within its range capability (just) but it will require a rapid charge at Kilmarnock both on the way there and the way back to make it comfortably, and that together with driving at 60 instead of 70 (which makes quite a big difference to range) will add about another 30 minutes to the journey each way, but at least we can still go. It's definitely a little city car, not designed for long journeys....

The delay getting the car back on the road and more parts needed before the MOT in a few weeks is annoying but I guess I'm just glad that the oil leak was discovered before any long trips were undertaken, and I'm quite annoyed that a Bosch branded filter has rusted out like that. It was a little bit overdue to be replaced but the car does hardly any driving so isn't exposed to as much road salt as the Ion, by far! It would be lucky if it does 2000 miles a year.

[Skull]

I didn't know what torque to use on the caliper bolts - I ended up doing it by feel and according to my torque wrench I used about 80 Nm. Does anyone have any idea what the correct torque is ? I can always re-torque them if it's too high or low.

Haynes says rear caliper securing bolts 47Nm or 35 Ibf ft no mention of thread lock

Read the rest tomorrow .....

[Mandrake]

Haynes says rear caliper securing bolts 47Nm or 35 Ibf ft no mention of thread lock

Uh oh, I better back them off a bit!

[Skull]

Simon good job on the rear brakes those were pretty scabby

That oil filter is a weird one alright I can't remember ever seeing that and is almost unbelievable The last time I stabbed one with a screwdriver to remove it they take quite a bit of battering before they leak. It's almost worth keeping a good old one for emergencies like that

[white exec]

Filter rusting out just could have been a bead of water in the oil (from lack of regular use) which caused local rusting. Water in oil will occupy a low point. Bit unlikely, but just remotely possible. Never seen anything like that before.

Caliper torques...

from the 2001 Mechanics' Handbook
Worth printing out that little booklet; full of really useful data.

[Gibbo2286]

Much more likely to have rusted from the outside, a tiny stone chip in the paint would be enough to let the rot set in.

[Zelandeth]

We've had a couple do that. One on a Fiat Panda (filter is right at the front edge of the engine bay) and one on my first Metro - though that looked like it had been there for 25 years!

So it's not hugely common but it does happen.

[Mandrake]

The filter has been on the car for 3 years (a bit longer than ideal I know) and over that time the car has probably only done about 10k miles. I like Gibbo's theory that road debris or stones chipped the paint enough to let water in and allowed rust to start that way. When I scrape the bubbling paint back half the front of the filter is not just surface rust it's completely exploded rust... Looks like very low grade steel to me combined with a pretty poor paint job. Made to a price.

I have a new filter and oil on order from Mr Auto that I am expecting on Tuesday. I thought about getting oil/filter from halfords or a local factor on Sunday but we had to go out in the morning so it wasn't convenient (it was also more expensive) so we took the other car to the beach. Apart from having to stop to rapid charge for 15-20 minutes on the way out and the way back at Kilmarnock the trip was uneventful, apart from finding toilets for a 3 year old to use while on the road that is... While the rapid charger we used was located at a Shell service station, naturally their toilet was out of order..

[Stickyfinger]

3 years, low miles, low mount, .....OK I can see that happening.

[white exec]

Diesels get a protective undertray, many petrols don't.
You would have thought that a Bosch item would have been reasonable quality, but how to tell?
At least you spotted it before it blew out. Maybe a blessing that the car wasn't taking you to the beach.

[lexi]

Lots of faffing, up and down on the knees on slabs, broken bolts, corroded calipers, oil leaks the lot..........luv a good work out of suffering................it makes you appreciate the days of bliss

[Mandrake]

3 years, low miles, low mount, .....OK I can see that happening.

Yeah, this car has definitely rusted a lot more (mostly surface rust) since it's mileage was drastically reduced. Even the alloy intake manifolds have a lot of aluminium corrosion on them now that they never used to. Cars don't like being left to sit around!