C5 X7 rear struts L&R removal

[aerodynamica]

Hi all, I am hoping to remove both rear hydraulic suspension struts on the C5 and the off side strut seems straightforward to access and remove with a rubber bung in the spare wheel well in the boot to give access to the upper fixing bolt. The near side one doesn't appear to have this access or am I mistaken?

[Jay-Bruce]

No Graeme, it doesn't have the grommet, but if you look at the near side one, it's not actually that bad, whereas the offside one would be all bar impossible without that grommet. I'm going to lift ours next weekend, start the pipework, firmness regulator and rear cylinder change over, will take photos for you. BTW, I checked the thread on the new cylinders, they are m8x1.25mm pitch, I keep meaning to measure the grip length required.

[aerodynamica]

Thanks Jay, that's good to know. Also thanks for recalling the query about the M8 screw. I actually trialled an M8 hex head bolt on one of the front suspension pipes a month ago and its holding out well. I think the original screw has a fairly long lead ahead of the actual thread - i wonder why. Perhaps the alignment is difficult before threading in. The screw I used had a full length thread.
Anyway, I'm doing the same job: replace the L&R 10mm pipes, firmness regulator and finally remove the rear spheres with the cylinders off the car.

[aerodynamica]

No Graeme, it doesn't have the grommet, but if you look at the near side one, it's not actually that bad, whereas the offside one would be all bar impossible without that grommet. I'm going to lift ours next weekend, start the pipework, firmness regulator and rear cylinder change over, will take photos for you. BTW, I checked the thread on the new cylinders, they are m8x1.25mm pitch, I keep meaning to measure the grip length required.

Not sure it is any help to you but I took a few measurements of the screw for the strut pipe flange.

Overall length - about 25mm

Length of thread - about 20mm

[aerodynamica]

I finally got the rear struts off! Fairly straightforward as it turned out. Amazingly the RHS suspension pipe actually did remove from the firmness regulator in the middle.

Immensely stuck (like everything on this car) but it removed!

one out

Very rusted

And the next task was to have another go at getting the corner spheres off as any attempt at this with the struts in the car was unsuccessful.

Again, with the HGV chain wrench and the longest breaker bar I have (about 4') neither would move at all and this was after using a wire spinner to clean the join to the strut - soak in plus gas for hours while I removed the firmness regulator, both were very much on there.. I resorted to the old medieval mode of chisel and lump hammer..

chiseled

and finally!

Martin at Plieades had warned my about the fragility of the C5x7 rear struts where they meet the sphere - I think the casting can chip but I was ok in the end.

I've had these two reconditioned L&R rear suspension pipes waiting since February and finally ready to fit them.

(re)newed pipes.

With the spheres off I tested them on the sphere tester to see how they fared after 15 years and they have around 42 bar left which is still quite a lot from their original 50 (I think is would be)

So these should be good for recharging.

Firmness regulator off with its rusty bracket

measured the damper valve from it to see how it compares to the front - around 1.6mm (front is around 1.8)

Lots of corrosion where the reg mounts to the alloy rear subframe. I couldn't remove the thin return pipe and have no way to replace it if I wrecked it. Also one damper valve can't be removed.

Also looked at the corner sphere dampers

measure around 1.1mm (similar XM hydractives are about 0.6mm)

So the temporary corner spheres are a pair of Xantia hydractive fronts with 40 bar left and a 1.0 mm damper)

My reconditioned hydractive firmness regulator to replace the removed one but unfortunately I couldn't remove one of the damper valves from the old unit to swap over (this is actually a front one) and also the rigid return pipe is totally stuck so I opted to clean up and refit the original regulator

And all of it back in. I think I'll return and refit the regulator I reconditioned at a later date as I have a pair of Hydractive 2 damper valves that have a slightly smaller center hole than the 1.6 I measured from the one valve I could get out of the C5, the Hydractive 2 dampers should hopefully give a better damped rear end as I feel the X7 is at times weirdly choppy at the rear (something I've seen on other Hydractive 3+ cars on the morotway) but I'll wait until I have the rear corner spheres recharged by Plieades if they hopefully can do them - they are quite rusty... All in all a long winded but quite happy job that consumed a full Saturday that was raining all day.. so time spent better.. I'm hoping now that the hydraulics are all going to last now that most bits have been seen to ... although I noticed the BHI motor/pump was sounding a bit noisier than I had noticed before...

[MattBLancs]

Good work, what a fight it put up!
Still love the visual indication of the green: "this bit: sorted"

Matt

[CitroJim]

Awesome work Graeme A huge well done and some considerable skill there not to shear anything off or otherwise damage it given all the corrosion!

As yet, I've never known the old hammer and chisel trick fail to remove a recalcitrant sphere!

[aerodynamica]

Ha, thanks guys, I had to get this stuff done - it would have bugged me forever.. but man, X7s love localised + concentrated rust!

[KennyW]

Well done Graeme,

I've looked at mine and thought I'll just leave it alone.

Kenny

[aerodynamica]

Well done Graeme,

I've looked at mine and thought I'll just leave it alone.

Kenny

Hi Kenny, yea it's a big job and unless you're really lucky then the 2 corner spheres just can't be undone. The problem is in the flexible rubber bushes at each end of the strut - they flex too much and you just can't get the torque on the sphere and you need a BIG force to get C5 spheres off. All 4 rears were off the scale tight, as was the front middle sphere. Only the two front corner spheres came off as easy as a BX front.

That said, the rear struts themselves are fairly straightforward to remove although you need a good torx 40 socket for the hydraulic pipe fixing. I got a new one specially for the job.

[Jay-Bruce]

Amazingly the RHS suspension pipe actually did remove from the firmness regulator in the middle.

Checks you showing off - oh I've got fancy non-seized hoses In all earnest, you did well getting them off the regulator, you'd get run off a rig for some of the tricks I tried on mine. And failed


But I've got newer ones to go on, came with my 23,000 mile firmness regulator that I imported from oz:


I've got to admit that as a hydraulics tech, I'm acutely aware of the dangers of accumulators, so there's no fricking way I'd be taking a chisel to a pressurised vessel as rusty as that... I'd save up and buy a cylinder. I've actually bought two, as one of mine was leaking, long running advisory on the MOT's "slight misting o/s/r suspension cylinder".


You're "temporary spheres" intrigue me, as I didn't quite get the serenity I wanted out of the car when I changed all seven spheres a few months ago. Since then I've been toying with getting some BX TZD, or C5 mkII "comfort" spec spheres to try and get the proper retro magic carpet ride on the go, but haven't fully decided what ones to go for yet.

The return line is something I can help with, PM me your address and I'll post you down something to try out.

[aerodynamica]

Hiya Jay, well I only managed to get the LH pipe out the regulator once it was on the workbench! I genuinely thought I'd be destroying at least one of them out but looking at the old rusty pair of pipes they -might- clean up and be able to refurbish.... maybe..

I agree to be cautious about striking a pressure vessel with a chisel but it's kind of a calculated risk - they are quite thick walled and especially at the 'equator' and of course, you're not driving the chisel 'in' but creating a notch then drifting it at a tangent to shock it free. Even if you were to puncture it the highest pressure sphere (75b) has a lot of stored energy but the volume is small and the chance of making a hole large enough to release it fast enough to injure seems really unlikely to me. Still, I see what you mean about corrosion, I suppose that adds a totally unknown factor in how it could fail but again I still think the rustiest sphere on the planet would have diffused its pressure long before the thing was structurally dangerous. Mind you, if you had a rusty sphere regassed! and then started striking it that could be the 'hundred year wave' right enough. There's a thread on here somewhere with failed spheres that had suffered hydraulic over pressure and had exploded - quite interesting to see them and I wouldn't have wanted to be nearby (or working under that car...) when they'd 'gone' .. but that had been the fluid pressure that destroyed them because the pressure regulator jammed and didn't cut out - not unknown on the old aluminium cast PRVs on pre 1970 IDs

Those temporary spheres are simply to keep the car on the road while Plieades have the spheres - I spoke to Martin yesterday and they have them now. It's funny you're not that impressed with the C5 x7 ride. I was disappointed with the rear suspension after I fitted the new center spheres 10 months ago and have been looking forward to attacking these corner spheres.. I was surprised they measured at 42 bar left because I expected them to be well lower given that the front center was about 27bar when it would've been 75 new. Martin commented that the C5x7 seems to be quite affected by small loss in sphere pressure whereas a DS or CX still rode well with spheres nearing 50% down. So I'm hoping they do improve the rear end on mine as the new fronts made a massive difference! I find the x7 front suspension to be on a par with a CX but with better insulation.. I don't know about anyone else but I find the X7 rear to feel really underdamped in some situations like it has a combination of too small a gas volume and too soft a damper but I'm not really certain why because it's only sometimes. All will be revealed with the corner spheres fixed and only then might I consider fitting the slightly firmer damper valves in the rear regulator.

Jay, that's great you got a good low miles regulator - especially with the crazy lack of new parts available for x7s...

Hey, I'd be delighted to try out your pipe solution! I do have a spare pipe but it's too short as the car breaker had simply snipped the metal .... why do they do that..

[CitroJim]

I've seen pictures of accumulator spheres that have ruptured due to a duff pressure regulator allowing uncontrolled pressure. The sphere tends to shatter and crack rather then explode. The pictures I've seen show no apparent collateral damage...

I've attacked recalcitrant spheres with club hammer and big chisel many times - and some very corroded ones too. Never a problem.

I'm not saying it's totally risk-free but I do believe the odds are vanishingly small and also, the sphere is likely to be flat or have very little pressure in it anyway...

[Hell Razor5543]

I have also had to use the hammer/chisel technique to remove an (otherwise) irremoveable sphere. The way I did this was to initially (and carefully) smack the chisel directly into the seam a few times, to create a purchase point. Then I would angle the chisel so that it would cause the sphere to unscrew. The combination of the impact shock and the twisting action would then get the sphere moving.

[aerodynamica]

I've seen pictures of accumulator spheres that have ruptured due to a duff pressure regulator allowing uncontrolled pressure. The sphere tends to shatter and crack rather then explode. The pictures I've seen show no apparent collateral damage...

I've attacked recalcitrant spheres with club hammer and big chisel many times - and some very corroded ones too. Never a problem.

I'm not saying it's totally risk-free but I do believe the odds are vanishingly small and also, the sphere is likely to be flat or have very little pressure in it anyway...

Works every time!

It's good to hear from you again Jim, I feel I've not heard from you in ages. I'm not on any other groups or forums these days