New C5 owner with a few questions already

[aerodynamica]

OK! I just read this thread about the H3+ viewtopic.php?t=69300&start=15 and I have now just learned that with Hydractive 3 the suspension is in soft mode when the electrovalves are NOT energised. This is the opposite to Hydractive I and II. It means that when I checked the electrovalve the car was simply standing and should be in soft mode and hence, the EV not energised anyway. Well, that's what I think now.

It's strange they chose to swap the modes around because in H1&2 a major fault sees the ECU power off and leaves the suspension in hard mode because it's the safer default. Even if it is rougher riding. I think the change was to save energy so that the electrovalves only need power in the sporadic need for stiff mode.

I also note from the detailed description in the thread that the height cannot be corrected in stiff mode because the spheres are isolated and the pressure locked in the centre sphere is what actually moves the valve to the stiff position. In H1 &2 the height could be corrected in both stiff and soft modes but I can see why they changed this aspect - it's electrically powered and the stiff mode is electronically controlled so any need to correct height could easily see the BHI switch off the electrovalve for that purpose (or simply not change height when stiff mode activates when moving)

It might explain why I was certain the car felt like the ride changed at times to stiff mode even though I thought it was not working correctly.

[aerodynamica]

Anyway, in the absence of new parts arriving I've been away from the car but I am now also realerted to something that came up on the first diagnostic I did before anything was fixed a few weeks ago.

This screen from the BSI scan has Fault: illumination of the rear stop lamp - short circuit to + (had this for L&R)

I spotted yesterday that only the middle stop lamp was working while reversing into the garage , I assume it has been like this since I got the car a few weeks ago. Now I have not looked at the bulbs yet or the fittings but I did search the fault and of course, it's a C5 problem.. I am getting prepared for a new epic. What does it mean by 'short circuit to +' I guess positive? Is this a bad earth type situation? Just trying to go in armed. If it's like my old XM the earths in each rear lamp cluster were inadequate and adding a big thick earth wire to the body from the cluster with tinned ring connections (just to make sure ) solved the problem and I had good bright stop and tail lamps once more. I am preparing my self for it being not so simple on the C5..

All other lamps in the clusters light as normal so I assume the earth points are ok. Unless the brakes have different earths?

I think the brake lamps are lit each individually from the BSI (?) and maybe the middle stop lamp too. The pedal switch must be working because the center lamp comes on and the Park position lock releases. You can hear the click of a relay on the passenger side any time the brake is pressed so it's something wrong at either the output of the BSI to the clusters or the clusters themselves. But what is that recorded fault telling me?

[aerodynamica]

OK! brake lights working... bulbs changed

[admiral51]

OK! brake lights working... bulbs changed

Been there done that

Colin

[aerodynamica]

to be fair! I was kind of expecting the dashboard to continually tell me the bulbs were blown every time I pressed the brake like on my old XMs.... OK, the XM tended to tell you that when the lights were perfectly functional

[aerodynamica]

After an epic wait the spheres I ordered turned up so I was super exited.

Also the front firmness regulator off a breaker showed up too. I must say I'm disappointed with the spheres as supplied: they are listed (on ebay) as 'brand new' and higher quality and in first looks they're nice and new with new O rings etc but with the protective cap off it immediately became apparent that the sphere neck had been crudely machined down and then seemingly had filed with a course metal file and the sphere neck has metal swarf in it. see the photo -

'new' rears

'new' rears

They also appear to have been repainted and the laser printed serial number on the top had been masked off with a strip of tape. Overall poor show.

These were not cheap and in fact cost about the same as the IFSH type and others. Both spheres of the rear pair are like this although the single front accumulator is apparently ok and has an undamaged sphere neck. See here -

New front sphere - good

I contacted the seller through ebay and am waiting on a reply. They were ordered last Monday, supposedly posted on Tuesday but didn't arrive by Friday as expected (although 3 other items ordered at the same time did including one from Ireland) It's annoying after waiting so long and that the old spheres being removed on Saturday rendered the car stuck on axle stands till today. Will see what he says...

As for the front regulator from the breakers, My plan for this is to replace the rear rusty unit with this completely unrusty front unit. I will have to swap over the damper valves within and also the block to fit the pair of accumulators for the rear but that's half the fun.

front regulator

I also plan to make some effort to protect it from rusting so badly. The front unit came with a front accumulator sphere attached and after removal (epically tight light the rears) I chucked it on the sphere tester. It is a sphere marked as 2008 and 75 bar and it measured 60 bar after 13 years. Actually not bad.

front 2008 accumulator 60b from 75b

I now wonder if the front accumulator that's actually on the car - and will also be from 2008 - might actually be about 60 bar too and that got me thinking that I could simply have fitted the two of these 60 bar accumulators to the rear. They're a bit high in pressure but not excessively.

Anyway, re the supplied rear spheres, I obviously didn't fit them and resigned myself to refitting the old rusty pair that are down to 40 bar. I did however work out that fitting the old front sphere that came with the regulator would actually render the rear circuit as having nearly the right amount of gas as two 52 bar rears. A 60 bar sphere and a 40 bar one (original old rusty rear) have a P.V value of 37000 combined and comparing that to the correct 2x 52 bar spheres of 38480 is very close so I decided to stick it on and see and it actually works very well. Remember the two rear center spheres are connected directly together to basically make one bigger sphere of 52 bar. The 60 and 40 combine to make a similar gas volume. You couldn't do that trick on the corner spheres of any Citroen as they need to be closely matched or you'd get uneven suspension at the same axle. But the unique arrangement of the C5 X7 and C6 with the double accumulator makes this possible. I still want to have the correct pair of 52 bar units in place but this will suffice for now. I'm just back from a lengthened route home with the C5 and it rode beautifully. I was also mistaken in thinking the rear electrovalve was faulty.

[aerodynamica]

Also got a new rear light to replace the oddly discoloured one

Was tempted to leave the paint pen writing on it

[aerodynamica]

Update re. the spheres. The ebay seller was apologetic and explained that they had 52 bar spheres that were actually c5 Mk1 fronts and so had a damper valve. They removed this and ground down the edge. The admitted they shouldn't have sold them as new rears and offered a refund so that's that. I suppose technically they are new spheres of the right pressure but the principle of paying nearly double the cost of LHM spheres and waiting a week puts paid to it. The guy is completely reasonable and offered a 50% discount on the right ones when they come into stock early next year. I will keep the new front sphere as it is as described and new and I'll fit it once I figure out how to actually access the front accumulator......

[aerodynamica]

Attempt and FAIL at removing the front suspension accumulator. It is absolutely inaccessible! Has anyone tried this before? You can see it (touch it actually) via the N/S wheel arch with the wheel removed but I could not get my chain wrench on it - not enough space around it: you have a steering rack pipe in the way, the track rod in the way and the subframe in the way. From underneath behind the engine you can see it easily but it's too far a reach to get anything on it - if they'd mounted it 90deg differently you could get a chain wrench on it and use a 3/4" extension to -maybe- crack it off. Tried the medieval chisel method and that would have worked using a very long chisel and lump hammer except the sphere and firmness regulator are fixed to their bracket with 3 flexible mountings so any shock the hammer and chisel could deliver are absorbed by these rubberised mountings...

You can't reach it from above because the brake vacuum can is in the way, as is the electronics box and oh, yes the engine too. It is completely stuffed in the corner low down and inaccessible. Contrary to the C6 whose front accumulator is simply found behind the wheel arch shield on the other side I believe.

I even got out my old, small chain wrench and I did manage to get that on it via the wheel arch with the steering at full lock to move the track rod more out the way and it might even have worked if it hadn't broken its chain! My usual chain wrench is an HGV type and it is just too bulky to fit.

I've been looking at the multitude of chain and oil filter wrenches and the only type that looks like they might do the job are those three- legged self adjusting type because they have the central location for the 3/4" drive so access from the wheel arch might work and might be slim enough to fit if I perhaps disconnect the tie rod end but the largest I have found so far is 120mm and that's about the limit because the grey spheres are about 120mm diameter. There is no access for any of the giant pipe gripper type wrenches so that's not going to work and a hefty strap wrench might work but I doubt any are strong enough for this.

It actually could be done if either the steering rack or the engine were removed... not even joking. Has anyone done this job?

Here's an idea of how tucked away it is, this is the front view even if you could get something on it there's no swing room

[Hell Razor5543]

This might be worth considering (from Xaccers);

https://www.frenchcarforum.co.uk/forum/ ... hp?t=21850

[aerodynamica]

Ah! thanks but the trouble is that the DIY tool needs space to swing the square section lever and you just can't do that on the X7. The only way I can see something working is if it's a type that kind of goes straight over the sphere 'crown' and has it's square drive in its center as that way it can be possibly done from the LH wheel arch. The kind of 3 prong oil filter wrenches seem about right but I just don't know if they can take this likely mega torque ...

[hattershaun]

Attempt and FAIL at removing the front suspension accumulator. It is absolutely inaccessible! Has anyone tried this before? You can see it (touch it actually) via the N/S wheel arch with the wheel removed but I could not get my chain wrench on it - not enough space around it: you have a steering rack pipe in the way, the track rod in the way and the subframe in the way. From underneath behind the engine you can see it easily but it's too far a reach to get anything on it - if they'd mounted it 90deg differently you could get a chain wrench on it and use a 3/4" extension to -maybe- crack it off. Tried the medieval chisel method and that would have worked using a very long chisel and lump hammer except the sphere and firmness regulator are fixed to their bracket with 3 flexible mountings so any shock the hammer and chisel could deliver are absorbed by these rubberised mountings...

You can't reach it from above because the brake vacuum can is in the way, as is the electronics box and oh, yes the engine too. It is completely stuffed in the corner low down and inaccessible. Contrary to the C6 whose front accumulator is simply found behind the wheel arch shield on the other side I believe.

I even got out my old, small chain wrench and I did manage to get that on it via the wheel arch with the steering at full lock to move the track rod more out the way and it might even have worked if it hadn't broken its chain! My usual chain wrench is an HGV type and it is just too bulky to fit.

I've been looking at the multitude of chain and oil filter wrenches and the only type that looks like they might do the job are those three- legged self adjusting type because they have the central location for the 3/4" drive so access from the wheel arch might work and might be slim enough to fit if I perhaps disconnect the tie rod end but the largest I have found so far is 120mm and that's about the limit because the grey spheres are about 120mm diameter. There is no access for any of the giant pipe gripper type wrenches so that's not going to work and a hefty strap wrench might work but I doubt any are strong enough for this.

It actually could be done if either the steering rack or the engine were removed... not even joking. Has anyone done this job?

The front subframe needs dropping to get at the centre sphere.
Recently had this job done on my C5, when all the spheres were replaced. Sphere was at 30b pressure instead of 75b; ride quality noticeably improved with the new sphere.
I was invoiced 2 hours workshop time. I suspect it would have taken longer had all the nuts/bolts not undone easily (subframe had been out not so long ago to replace anti roll bars).
Good luck!

[bobins]

Factory workshop manual says that the subframe must be removed, then the sphere and its bracket can be removed as one once you've done all the other unplumbing and disconnecting. You might find that you can remove the sphere without removing the mounting bracket first though.

C5 Sphere - PSA, fair use

[aerodynamica]

Thanks guys, my word that is actually insane. Subframe must be removed/lowered!
I mean the actual removal of the sphere by hand is an elbow deep operation but I've done worse - once it's cracked there's enough room to remove it. It is simply the loosening that is the problem.

Hm.. maybe the ride is actually OK

[Hell Razor5543]

Well, consider that the C5 spheres have a far longer lifespan than those on the Xantia, for example, and you could understand why Citroen haven't thought ease of access to be a major consideration. Still, having to drop the subframe is still a pain in the proverbial!