Pesky Xantia rear caliper bolts

[Old-Guy]

I've tried every Citroen dealer within a 30 mile radius - nobody has any in stock. I've been told this is no longer a dealer stock item, so you'd be very lucky to find someone who has them in stock. The good news is that this morning Citroen's system shows them as being in stock in the UK. I have two sets on order - with the Bank Holiday they probably won't arrive until next Thursday.

Anyone planning to remove the rear calipers should order new bolts well in advance and not start the job until they have them to hand.

[RichardW]

When you get them, measure the shank and threaded part and post it up - then we will have an aftermarker reference (for estate at least, as I said, M9 for hatch is much more difficult).

[Old-Guy]

Good plan Richard - will do. It looks as though they might become unobtainable before long and assuming that someone else uses makes a similar, but longer bolt (though probably 17mm head) in the right material (head bolts?) it would be a doddle for a small machine shop to convert them.

[reblack68]

Are they a fine M10x1.25 thread like the C5 or are they standard M10x1.75 thread?

Edit- just checked Citroen Service and they are indeed M10x1.25, and 140mm long. The C5 items are the same thread but 150mm long, they would do if the thread is long enough.

[Old-Guy]

You can bet that the extra 10mm is (mostly) in the plain shank, not entirely in extra thread.

[reblack68]

I imagine that would be the case. I have two C5 bolts somewhere, I'll measure them up tomorrow and somebody can measure a Xantia Estate caliper.

[reblack68]

I've measured a C5 bolt now, from a 2001 1.8LX but it seems the same bolts fit a 2002 C5 HDi 110 LX Estate. 124mm to the start of the thread, 148mm overall.

[KennyW]

If I remember rightly, you can buy the M10 bolts with the right steel strength on Line but the problem is the M9 bolts for the saloons.

Anybody going to France or living there,can checked with dealers to see what the stated of stock or in stock there is.

I have an estate bolt in the garage is the measurement required.

Kenny

Estate bolts are M10 140mm long, 121mm non threaded and 19mm threaded.

[addo]

Drill and tap, may be the solution.

[falling-out-with-my-car]

I find with any seized bolts a good wire brush and gentle fine coaxing with a pair of very good quality baby stilsons you might if your lucky be able to tighten the bolts ever so slightly before you start to unscrew them, I remember my Father had to source some second hand bolts from a scrap yard that removed them for you becuase they were not covered on the insrance to allow the public on sight. I am pretty sure the yard was on the A5 and called French car spares but I shall check that. with him.

[CitroJim]

I am pretty sure the yard was on the A5 and called French car spares but I shall check that. with him.

The one just past Hockliffe and just before Dunstable?

[falling-out-with-my-car]

Jim you are a star
If you get techinal to much with them they dont like it very much and dont ask them to handle a written list
I think one of the gents has problems reading but the service is great if you know what you want and can explain it easily their mechanical knowledge is very good indeed. it is A5 car spares "French car specialists"

[Old-Guy]

Thanks for all the data chaps.
To recap: Xantia Estate bolts, pt no 4405.26 are M10x1.25, 140mm long - 121mm plain plus 19mm thread.
To adapt Mk1 C5 bolts (M10x1.25, 148mm long - 124mm plain plus 24mm thread), it would be necessary to cut an extra 3mm of thread and shorten by 8mm; it wouldn't be essential to cut off the extra 8mm, but the redundant 8mm of thread protruding into all the flying muck will simply corrode like fun and make subsequent removal even more difficult.

Calliper bolts are a safety-critical item and any corrosion between calliper and swinging arm will over-stress them at the start of the thread - the worst possible place - so I'm very reluctant to re-use them. The consequences of one shearing at the start of the thread doesn't bear thinking about

I've just checked the BoL for the torque setting, but as the disc dims are quoted as 224 dia x 9 so the 47NM torque quoted is for the 9mm saloon bolts, my mental arithmetic makes it about 54Nm for M10.

[Old-Guy]

Today I picked up the set of bolts today that were ordered last Thursday (phone call yesterday to say they had been delivered - with a Bank Holiday in between, pretty good service).

I've checked the dimensions - as in my previous post except that I've measured the actual threaded length as a good 20mm. Even without a thread gauge I can confirm that they're definitely 1.25 pitch (not the standard 1.5 for M10) and that the heads are stamped 10.9 (high tensile). They look to be finished 'zinc and passivated', so that's three dissimilar metals!

While i was out, I also bought myself a new set of stud extractors and a 16mm impact socket (I couldn't get a single short 16mm flat-drive socket anywhere), but resisted the offer of a 600mm breaker-bar as I'd be absolutely certain to break them with it. I know the bolts are really tight and slightly bent so I do expect to break all 4 anyway, leaving broken stumps to be extracted from the swinging arm, but at least the stumps won't be under tremendous tension and I'll be able to soak the threads with penetrating fluid from both ends. Plan for the worst and hope for the best.

Tidying up in my 'office' at home on Monday while the rain poured down outside, I came across some blank A4 OHP slides designed for printing by a laser printer - so rather more heat-proof than polythene, quite stiff and beautifully flat. It occurred to me that, as I intend to take each calliper off in turn to clean them up on the bench, I could scan the mounting face of one as a line drawing and print the result as full size on an OHP slide as a perfect 'gasket'!

[CitroJim]

Tidying up in my 'office' at home on Monday while the rain poured down outside, I came across some blank A4 OHP slides designed for printing by a laser printer - so rather more heat-proof than polythene, quite stiff and beautifully flat. It occurred to me that, as I intend to take each calliper off in turn to clean them up on the bench, I could scan the mounting face of one as a line drawing and print the result as full size on an OHP slide as a perfect 'gasket'!

What an absolutely brilliant idea