Simon's new Xantia V6 and Leaf blog

[Mandrake]

As time is getting so tight on the MOT for the Ion (it runs out on the 16th) I phoned my local garage on Monday and booked the MOT for this Saturday - before I've even done the discs...

So yesterday I took a day off work on one of the very few predicted fine and sunny days and got to work. The old discs, which were only fitted 2 years ago were in some state - the edge was totally corroded and exploded with rust and long strips of the rusty edge were missing at the tip of the disc - no wonder there was vibration at speed (pad going between rusty strip and missing rusty strip and lots of grinding in general...) the pads were also very badly glazed and seized in the caliper.

After recently learning how important minimising run out is when fitting new discs, this is the first time I've used a dial gauge while fitting discs and it was a bit of an eye opener! I'm so glad I got a dial gauge and thanks to Chris (?) for recommending one that was very affordably priced (just over £20) and has proven to be perfect for the job.

When I fitted the last discs I did what in hindsight might have been a mistake - coating some copper grease between the disc and hub, something I've never done before. Unlike normal grease copper grease is quite thick and does have metallic copper in it so could potentially cause the disc to not sit perfectly true and introduce some run out - the article about run out (which I posted here a while ago) warned that even a tiny spec of rust between disc and hub can introduce significant and problematic run out and advised the surfaces should be scrupulously clean and free of any contaminants.

The article warns that even 0.1mm of run out is enough to initiate a chain of events that ultimately leads to thickness variation of the discs and vibration. Essentially the pads over time wear down the "high" sides of a disc with run out - which is the opposite angular position on each side of the disc. This reduces the run out on each side (as measured by a dial gauge on one side of the disc only) but introduces thickness variations around the disc which result in vibration under braking, which is probably exactly what has happened. The article recommended that run out of a new disc measured in the middle of the swept area should be no more than 0.04mm.

So I cleaned the surface of the hub with kitchen roll and "gunk" cleaner (similar to carb cleaner) to get all the grease off and did a test fit, numbering the positions on the disc so that I could measure the run out in each of the four possible fitting orientations. There is no retaining screw on these discs so it's necessary to put the wheel nuts on with spacers to perform the run out measurement:

The initial result was a little surprising and disappointing:

1 - 0.1mm
2 - 0.08mm
3 - 0.13mm
4 - 0.1mm

So if I had just slapped the disc on without measuring the run out and hoped for the best, even though I gave the hub surface a cursory clean, I could have ended up with anywhere from 0.08mm to 0.13mm which is far too much according to the articles I've read, and would definitely lead to thickness variation over time. So the disc came off again and I felt the surface of the hub carefully with my fingers and could see and feel very slight raised bumps in a couple of places - not sure if it was corrosion or something sticky, but something was there so I got out some kitchen steel wool (the fine stuff with soap in it) and gave the surface of the hub a good hard scrub and managed to remove whatever it was on the surface until it felt smooth. Whatever it was was quite resistant to being removed and needed a lot of scrubbing.

I then retested the fit and run out and got:

1 - 0.05mm
2 - 0.04mm
3 - 0.04mm
4 - 0.05mm.

About a factor of two improvement and also virtually no variation with fitting orientation. I then nipped the nuts up a bit tighter with a socket and the figure reduced to 0.03mm and I was happy with that and continued with the pads etc.

On the other side of the car I just went straight to scrubbing the hub scrupulously clean with the steel wool, then on first fitting I got:

1 - 0.04mm
2 - 0.03mm
3 - 0.02mm.

I didn't test position 4 because by the time I got to 3 it was already better than the other side of the car so I was more than happy with it and just left it there. (I suspect it would have measured 0.03mm anyway)

So I'm very glad I had a dial gauge to test this and would whole-heatedly recommend anyone fitting new discs not only to take extra effort to get the hub face scrupulously clean (it needs scrubbing with something slightly abrasive like steel wool) but to also measure the run-out to verify that it is sufficiently low. If a spec of rust got trapped between them you'd immediately pick that up with the run out measurement. Even the 0.13mm run out was invisible when eyeballing the disc.

The discs are Brembo but I ended up buying "Blue Print" pads, partly because I liked the load spreading shims they came with, which some of the other pad brands did not have:

Unfortunately, exactly like the Apec pads that I fitted last time, the total pad length from ear to ear is at least 0.5mm longer than the gap available to insert them! It's physically not possible to force them in, and even if you did they would be jammed and would not be able to move freely. So just like last time I had to file a good 0.5mm off the tips of each ear on the pads to get them to fit and allow a slight bit of vertical slack (taken up by the spring shims) so that the pads don't jam over time. I'm not particularly happy about doing that because it means filing the anti-corrosion layer off the ears which means they will rapidly rust at the tips - but I don't know what else I can do if they won't fit ?

That's two different after market parts brands with the exact same problem - so is it the car to blame or the dimensions of the pads ? I don't know... in every other regard the pads seem to be of good quality.

The caliper slide pins were still in perfect condition, still greased from last time and moving freely so I left them alone. I then put everything together and went for a long drive to bed them in gently, as I think in the past I have also been a bit aggressive in bedding in new discs and pads. I ended up driving out to Richard's neck of the woods and testing his local rapid charger...

Since then I've also driven to work today and so far at least it has been a resounding success.

1) No more constant vibration from the front at motorway speeds. (even with the brakes not applied) This would have been the intermittent rust spiral at the edge of the disc hitting the pads and/or run out.
2) No more vibration when braking from high speeds. (No more thickness variation or run out)
3) No more grinding when applying the brakes at low speeds, or any speeds for that matter. (No rust)
4) Nice sensitive bite especially when pulling to a stop, but progressive and controllable. (Good, even pad contact with the surface of the disc and no rust)

It's totally transformed the brakes of the car from "Meh" to working very nicely and with a good "feel" to the brake response. Hopefully the coating on the Brembo discs will resist corrosion a bit better than the Apec ones, especially around the vents, and hopefully now that the run out is extremely low there won't be any odd wear patterns to the discs that will introduce thickness variations over time.

So it's in for the MOT on Saturday, however I think it is going to fail on the front right tyre - not only is it bald on the edge it's now cracking and starting to disintegrate on the bald edge as it seems to have worn through to a "lower" layer in the rubber. DOH! So it might need a pair of new front tyres as well. But I suppose new tyres and new discs/pads may be a good selling point to a prospective buyer!

[white exec]

A thorough job there, Simon, and a satisfying result. Brilliant!

The shims often supplied with pads are usually part of the car's parts line-up (or maybe one of the cars that they fit), and are there usually to eliminate brake squeal. They do this by acoustically coupling disc, pad and caliper into a single 'lump', and this preventing "wine glass ringing" when the disc is stroked by the pad. Some shims come coated with a black substance, which obviates the need to apply Cu grease to the shims, pad backs and caliper/pistons. I usually apply a light smear anyway.

Odd that you've had two sets of pads that aren't a proper fit. Bit of rust on the pad ears won't hurt, and could be Cu greased anyway. Also normal for lots of makes of disc to rust on the periphery, and shed strips of swollen rust. I usually poke it off with a well-placed chisel, while rotating the disc; probably a pointless exercise.

Good luck with MoT and its tyres. Every car needs something minor to fail on, as it keeps the testers happy.

[Mandrake]

A thorough job there, Simon, and a satisfying result. Brilliant!

The shims often supplied with pads are usually part of the car's parts line-up (or maybe one of the cars that they fit), and are there usually to eliminate brake squeal. They do this by acoustically coupling disc, pad and caliper into a single 'lump', and this preventing "wine glass ringing" when the disc is stroked by the pad. Some shims come coated with a black substance, which obviates the need to apply Cu grease to the shims, pad backs and caliper/pistons. I usually apply a light smear anyway.

The original pads on the car when I bought it - which I believe were the original 6 year old pads had no shims at all, and squeal was a problem. When I bought the original Apec pads and discs a couple of years go the pads did not come with shims either - but Peugeot have an optional set of anti-squeal shims with a black rubbery like substance on the side facing the pads which can be bought, presumably to damp any vibrations - so I fitted those anti-squeal shims on the Apec pads and haven't had any squeal problems until very recently.

The Blue Print pads came with their own shims however unlike the optional Peugeot ones they do not have any coatings on them, they are just a steel shim - what you see in the picture is what you get. I have deliberately not added any coatings or grease at all. So far they are quiet and squeal free, lets hope they stay that way.

Odd that you've had two sets of pads that aren't a proper fit. Bit of rust on the pad ears won't hurt, and could be Cu greased anyway. Also normal for lots of makes of disc to rust on the periphery, and shed strips of swollen rust. I usually poke it off with a well-placed chisel, while rotating the disc; probably a pointless exercise.

The pad ears definitely don't fit - and are too big by about the same amount as the last lot, which makes me think the after market guys have somehow got the wrong dimensions, or perhaps their pad is based on the petrol version of the car and there are subtle differences in the brakes on the EV version ? I notice that the brake caliper has stamped in huge letters "EV" - whether that means it's an EV version of the caliper or its coincidental I don't know...

Fortunately the pad ears don't touch the caliper steel directly, there are thin stainless steel shims which also double as spring tensioners that they press against - no direct steel to steel contact so corrosion welding together shouldn't be as bad as steel to steel, although the old pads were still wedged in pretty tight.

Good luck with MoT and its tyres. Every car needs something minor to fail on, as it keeps the testers happy.

I'm a bit annoyed about the tyre - it's been bald just at the edge for a few months now but literally in the last couple of weeks it seems to have worn through to another layer and started cracking. I reckon it's going to be a fail and I feel bad about taking it in to fail, however I simply don't have enough time to order in tyres, have them fitted then book in an MOT, the MOT will have expired by then. So I'll have to let it fail and then ask them to keep the car and order in tyres and finish the MOT once they're fitted.

I can drive the Xantia while they keep the car - the compressor pulley is still a bit noisy (but not nearly as noisy now the weather is dry!) but the gear change is working perfectly since all the fiddling around with the ECU connector...

[DHallworth]

You might be surprised about the tyre, Simon.

As long as it's got tread across the top 3/4 of the tyre and you can't see the canvas/carcas of the tyre through any of the cracks you should be ok.

David.

[Mandrake]

Well the Ion passed! With two advisories though.

No comment at all about the tyre, so it looks like I was focusing my worry in the wrong place. He pointed out that all four brake pipes are very rusty, in particular the rear ones which he was quite concerned about. I can't say I've noticed the front ones however he certainly has a point about the rear ones - when the motor cover is removed in the boot you can see the rear brake lines where they emerge from the gap between the body and battery pack before splitting off to the rear corners and they are extremely rusted and quite iffy looking.

I was aware of this but they've been like that for a long time and they could do with cleaning up and painting with hammerite but to be honest I'm scared to touch them with steel wool for fear that they might disintegrate...

Anyway it's a pass so the immediate pressure is off now. I had a chat to him about the air conditioner on the Xantia and he said they can look at that no problem. When I described the symptoms he said it sounds like the "shear pin" in the compressor has failed, probably due to lack of lubrication or the compressor seizing altogether.

I assume by shear pin he means the shaft after it goes inside the compressor has a reduced diameter section that is deliberately weak and designed to shear if the compressor seizes up, in preference to seizing the entire pulley and dismembering the aux belt..

That explains all the symptoms perfectly:

1) The failure was sudden, probably on start up of the engine after the car had sat for several weeks and the compressor had finally seized....
2) There is no cooling action at all now after the sudden failure despite the system still seeming to be pressurised (because the compressor innards are no longer turning even when the clutch is engaged..)
3) The noise when the clutch is engaged is the broken piece of shaft inside the pump wobbling around only supported by one bearing instead of two.
4) The pulley wobbling slightly is for the same reason - only the bearing at one end of the compressor is still attached to the exterior shaft!
5) The metal scraping noise when the clutch is not engaged is because without the load of the compressor pistons the shaft stub in the end of the compressor will turn too easily, meaning that even when the clutch is disengaged it will be dragging slightly and trying to spin that loose stub.

Anyway now the Ion is MOT'ed I've booked the Xantia in next Saturday and will leave it with them for the week - they'll first vacuum and pressure test the system to make sure there aren't any leaks before ordering a compressor, however I think it will test OK as the pressure switch still reports enough pressure to engage the compressor clutch even now.

I've also discussed the possibility of them replacing the lower arm bushes on the front right suspension dependant on cost - I'm not equipped for replacing the bushes and I'm not keen to order an after market arm with cheap bushes on it.

When talking about it he agreed that it was better to fit OEM bushes to the original arm than to buy an after market arm with bushes already fitted as he's found some of them to be quite poor quality. That clonk in the front right suspension has been there since I got the car and getting worse gradually despite my and Richard's attempts to find it. It's getting quite bad now and really starting to annoy me and I'm convinced it must be the arm bushes so time to finally get them replaced.

So my stress levels are down a bit now - one car MOT'ed and the other one on its way to being back on the road properly. We have holiday plans in April that are a bit beyond the comfortable range limits of the Ion so I'd like the Xantia to be working properly before then.

We might have a Leaf by then which could make the journey reasonably easily (although not as easily as the Xantia) but as I'm holding out for just the right one we might not!

[Mandrake]

So the Xantia is in at the local garage being checked today, got a phone call to confirm that there is still adequate pressure in the air con system so at this point they don't believe there is a pressure leak and that it's worth going ahead with replacing the compressor (which is definitely dead) and regassing the system.

Regarding the front lower suspension arm bush replacement after looking at them he's now recommending it would be better to just replace the arm with a replacement one with new bushes rather than trying to press the bushes onto the old arm. If that's the case I'm wondering whether I'm better off just doing that job myself later ? He also recommended both sides be done as the other side looks pretty bad as well. (Although there is no clonk from the left)

Does anyone have any recommendations for a decent quality lower front suspension arm for the Xantia with bushes ? And what sort of heavy tools would I need to do the arm replacement ? Just trying to gauge how feasible it is for me to swap the lower arms myself and whether I have adequately beefy tools to do the job. (Although I would wait until the spring or maybe even summer to do them as it's a non-critical elective repair)

I would imagine that trying to get the nut off the bottom baljoint to free the arm could be tricky if the hex is rusted out ? And a new nylock nut is required when the new arm is fitted ?

[Hell Razor5543]

It was quite a while ago when I replaced the arms on my Xantia (citronut helped me), but one trick I do remember is NOT to torque up the securing bolts until the Xantia is bearing its weight on its wheels, and the suspension is at the normal setting. This will allow the bushes to get into their default position, and therefore they will last properly. If you tighten up the bolts with the arm hanging down the bush will then be flexed when the car is bearing its weight, shortening the life of the bushes.

[RichardW]

Cheap arms ( or bushes) will not last. I don't think it's so hard to get them out, and if you're not time pressed then changing the bushes will be cost effective. Hardest bit is the through bolt on the front bush (but should be ok with the impact driver), and getting the arm back in without wrecking the front height corrector (I'd disconnect to be on the safe side!).

[Mandrake]

I don’t have any tools to remove the old bushes or press on the new ones though, which is why I originally was going to ask the garage to do that.

Does nobody make a good replacement arm with decent bushes ? Has everyone here just fitted new bushes to the original arm ?

Regarding height corrector damage - as long as the drop links are left attached to the struts I don't see how the height corrector would be damaged ? The suspension travel limit stops are both in the hydraulic ram, the lower arm doesn't play any role in that.

[Mandrake]

Is an actual press needed to get the bushes off the old arm and fit the new ones, or will a vice and block hammer be sufficient to hammer the new bushes onto the arm ? How firmly are the bushes pressed onto the arms ?

[Stickyfinger]

Most local garages will press in some bushes if you give them a few pints

[Mandrake]

Just looking at replacement arms - there seem to be a lot of different makes available:

https://www.mister-auto.co.uk/suspensio ... 1997-2003/

Surely the Lemforder one would have good quality bushes in it ? Would that not be OEM ?

[Stickyfinger]

Yep....that price is shocking however.

[Mandrake]

Yep....that price is shocking however.

It's also the wrong side, when I look up the part number elsewhere it shows as front left despite being listed as "drivers side"...(I guess the website is European) They don't list a Lemforder one for the other side.

How about this SKF one ?

https://www.autodoc.co.uk/skf/13663875

SKF should be decent ?

[Skull]

How firmly are the bushes pressed onto the arms ?

I managed to insert mine on a vice with a suitable socket to help keep the bush square and some spray lube, I opted to do both bushes on one arm but in hindsight I could have just changed the knackered rear pivot one - removing the good bush was a lot of effort, the knackered rear pivot bush fell off, apart from the metal sleeve which needed an angle driver to cut off carefully

Buy both bushes but see what condition the front one is before attacking it