Xantia strut tops acquired! But mod needed

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aerodynamica
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Xantia strut tops acquired! But mod needed

Post by aerodynamica » 07 Jul 2018, 20:11

Hi all, thanks to Mirifioriman I have a replacement pair of Xantia strut tops and gaiters in good condition.

Image20180707_153744 by Graeme McNulty, on Flickr

I need to convert the new struts with small pipe connections to the larger 10mm pipe fixings for hydractive type.

Here's the hydractive pipe connectors:
Image20180707_153803 by Graeme McNulty, on Flickr

And the new strut top with small pipes:
Image20180707_153815 by Graeme McNulty, on Flickr

I've had a look at various old threads on here concerning the difference between the two. Some good info from Chris in Malaga but I'm keen to get an accurate set of info on the dimensions needed for the Hydractive pipe connection. I guess the inner bore is 10mm or a little more and the depth of the union bore can be measured but anyone know the size and thread pitch of the hydractive pipe union nut? It measures at about 15mm but not looked at the thread pitch - looks quite fine.

Any help greatly welcomed!

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Re: Xantia strut tops acquired! But mod needed

Post by white exec » 07 Jul 2018, 21:20

Hi Graeme,

Just put an XM HA strut top on the bench.
The 10mm HA pipe opening is as follows:

Threaded M16 x 1.5 (I think, but I don't have a tap that big to check), threads go to a depth of 17.5mm from the outside.

Immediately below that is a taper/countersink, which I think is 45deg, but not easy to measure. Check with your own HA pipe end.

From there on, hole continues at 7.5mm diam., to break out on the central drilling.

IIRC, this is a 'compression' joint, seal simply by the outer union on the 10mm pipe belling. No seal.


Caution?
Not sure whether your non-HA tops have the same taper dimensions as HA struts.
You'll remember that John indentified a good many types/combinations of strut and strut-tops across (XM) models.

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Re: Xantia strut tops acquired! But mod needed

Post by aerodynamica » 07 Jul 2018, 22:41

That's brilliant Chris thanks, just what I needed.

Yes, I'll remove one of the pipes on the car and have a look at the taper.

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Re: Xantia strut tops acquired! But mod needed

Post by aerodynamica » 09 Jul 2018, 22:38

white exec wrote:
07 Jul 2018, 21:20
Caution?
Not sure whether your non-HA tops have the same taper dimensions as HA struts.
You'll remember that John indentified a good many types/combinations of strut and strut-tops across (XM) models.


I just read this again. Do you mean the taper where the top of the strut mates to the strut top to protrude for the nut on top?

I thought the only difference on Xantias was between the V6 and all others?

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Re: Xantia strut tops acquired! But mod needed

Post by white exec » 09 Jul 2018, 23:26

Just recall that John identified different strut sizes (and designs) across XM range and time - some compatible, some not - and wondered whether this might also apply to Xantia.

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Re: Xantia strut tops acquired! But mod needed

Post by aerodynamica » 15 Jul 2018, 20:14

Hi Chris, yes I think I remember that - I think it was governed by whether the strut was 22mm or 25mm diameter internal for the XM. IIRC the majority were 22mm but 2.5 litre and V6 were 25mm. I truly hope these items I have are the same as the outgoing pair! otherwise I've just thrown away a wad of cash..

Thanks for the initial thread size dimensions - I can confirm that it is a thread pitch of 1.5 and thanks for the essential inner dimensions especially the depth of the thread. I was wondering about the size of the smaller internal diameter, measured at 7.5 - I was half expecting it to be closer to 10 or more because the pipe is 10mm? (I couldn't really measure this on my car yesterday)

Anyway, thanks again and I'll update on the project

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Re: Xantia strut tops acquired! But mod needed

Post by white exec » 15 Jul 2018, 23:03

The innermost drilling (at the bottom of the threaded hole, leading into the central strut bore) was 7.5mm - I checked it by inserting a drill bit - and that would be not far off the ID of a 10mm OD pipe.

You might (?) be able to check your strut shaft diameter by measuring the diameter of the strut top hole visible if you remove the top nut. Removing the nut shouldn't allow the shaft to disengage; that will require a hefty hammer blow (use a bit of flattened copper pipe to protect the shaft-end/nut when you eventually hit it!).

Shaft diameter also easily measured by dropping the strut gaiter.

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Re: Xantia strut tops acquired! But mod needed

Post by aerodynamica » 16 Jul 2018, 12:38

Thanks, my confusion regarding the 7.5 vs. 10 mm bore is that I imagined the 10mm pipe slots into that narrower drilling just in from the olive? Does it in fact merely mate up to it?

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Re: Xantia strut tops acquired! But mod needed

Post by white exec » 16 Jul 2018, 16:33

The end of the 10mm pipe is forced against the c.45deg taper (countersink) by the threaded insert. It differs from other smaller pipe joints on the car (which have the rubber tubular seal), in that there is no seal - just metal-to-metal contact.

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Re: Xantia strut tops acquired! But mod needed

Post by aerodynamica » 16 Jul 2018, 16:48

Got you, I suppose the tapered part will have to have a very good finish to seal properly.

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Re: Xantia strut tops acquired! But mod needed

Post by white exec » 16 Jul 2018, 20:18

Maybe, maybe not. Can't remember the exact shape of the 10mm pipe end now, and its angle, but you'll see it when you undo yours.
Just taken another look at the new strut top here, and the countersink at the bottom of the threaded hole looks to have an angle of 30deg [0deg would be a flat-bottomed hole], which looks to me to be the same as a standard HSS twist drill bit.
The surface of the csk is not dead smooth, but has visible but fine machining lines running round it, which can just about be felt with a scriber point - so it looks as if this surface doesn't have to be perfectly smooth. Clever things, Citroen hydraulic joints, considering the huge pressures they operate at.

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Re: Xantia strut tops acquired! But mod needed

Post by aerodynamica » 16 Jul 2018, 22:47

Thanks Chris, duly noted