C5 (X7) 3.0HDI - suspension pump brushes and height sensors

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MGmike
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MGmike »

Jay, keep the faith, we'll get there in the end and you'll kick yourself when it's something easy... I know, I've been there! :lol:

On the C6 it's on the drivers side of the radiator sitting on top of the main chassis rail, essentially to the right of the suspension pump looking from the front. It'll be a fairly large, probably brown, relay. you need to confirm there's 12v on one of the two thicker wires. If there is, pull the relay, make up a jump lead from wire of a suitable size and bridge the two thick wires. That should put 12v straight to the motor connector. There should also be 12v on a smaller (trigger) wire for the relay coil. If this is absent go check F13 on the BSI. Also if you haven't already done so, remove and reseat MF4 (the big one under the engine bay fuse box (BSM)) they have been known to go high resistance and, although they measure continuity okay with a meter, they don't pass the level of current required to run a motor.

Marc,
do you have a copy of the diagram that lists the component No.'s and their locations (part of the loom layout I think)? That'll help me direct Jay to the correct locations.
Cheers
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by Jay-Bruce »

It's Sorted!!!

After Mike helped me cheat at Citroen's game of hide the fuesebox, and I've got to say, without him telling me to remove the BSM fusebox to find the maxi fuses, I'd never have found it, but after I did, I cleaned all maxi fuse blades, found a blown 50A fuse, replaced it done some multimeter checks, all looked good. So I fired her up and rejoiced as it moved from gangsta supa star low rider pimp wagon and raised itself off it's sills all the way up to SUV-worthy ground clearance at max ride height setting.

It's running, so I'm happy, I've still a few things to do, like sort that broken wheel stud, find out why the airbox is rattling, and adjust the ride heights. The reason for the heights needing reprogrammed is that as part of my plan to "malky" this breakdown, as well as the low mileage used BHI replacement which I then servied the motor on, I replaced all four height sensors with brand new ones and homemade replacement links (the oem part is no longer available), so the height probably wants reprogramming. But that said, her stance already "looks the part" much more than she did on the old sensors, which might explain why there were some fault codes for them at the start of this saga.

Between trying to find unobtainable angular pick-up rods, and reverse engineering replacements, playing fusebox hide and seek, hunting for a like for like BHI, and setting up new diagnostic equipment to talk the suspension ECU, I have been "on" this car every day of my leave, so yeah, it is a genuine delight to be able to see an end to this chapter of the "enthusiastically maintained with no expense spared" saga.

Muchos Kudos to all who have helped me on this journey by contributing to this tread, but standing ovations for Marc "GiveMeABreak" and Michael "MGmike" - without your contributions to this thread this wouldn't have ended well. Thank you sirs.
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MattBLancs
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MattBLancs »

Excellent news, at last!!
MGmike
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MGmike »

Jay-Bruce wrote: 01 Nov 2023, 01:06 Muchos Kudos to all who have helped me on this journey by contributing to this tread, but standing ovations for Marc "GiveMeABreak" and Michael "MGmike" - without your contributions to this thread this wouldn't have ended well. Thank you sirs.
Bugger, I should have let you break it some more and when you got fed up, bought it for scrap :rofl2:

Well done you for sticking with it =D> and I want first Dibs if you do sell :mrgreen:
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c16rkc
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by c16rkc »

What a great read!

I am so pleased your car is working now, what a lot of messing around you had to do; though this does seem to mirror everything I have done on my C5 X7... so I am thinking they are all this naughty! :lol:

One thing I can't get over is how rusty these cars get. I thought mine might have been driven in the sea or something, but it's interesting to see all your suspension components are absolutely covered in rust just like mine. I can only assume Citroen used some incredibly low grade steel for the production of most of these brackets, arms etc.
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MattBLancs
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MattBLancs »

c16rkc wrote: 08 Nov 2023, 14:27 What a great read!

I am so pleased your car is working now, what a lot of messing around you had to do; though this does seem to mirror everything I have done on my C5 X7... so I am thinking they are all this naughty! :lol:

One thing I can't get over is how rusty these cars get. I thought mine might have been driven in the sea or something, but it's interesting to see all your suspension components are absolutely covered in rust just like mine. I can only assume Citroen used some incredibly low grade steel for the production of most of these brackets, arms etc.
Much discussion about dissimilar metals / galvanic corrosion! Basically chunks of steel and aluminium physically bolted together (ie electrically coupled) and regularly doused in salty water = electrolyte seems to be at the heart of what's going on! Basically an electric car but not like that...
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by Jay-Bruce »

Two years ago, my car had a full "front axle overhaul", new pads, discs, both wheel bearings, new left refurbished driveshaft, top and bottom ball joints etc... Yet it's still that rusty, like fifteen thousand miles later. It looks like they are badly designed in terms of the metallurgy, as Aerodynimaca said "It looks like the X7 is an exercise in galvanic corrosion". Fortunately mine is still solid, just crusty. But you're not the only person to comment on it looking crusty underneath, so I'm going to clear some time and rip off the undertrays, needle-gun/wirewheel the underside, dowse it in kurust type rust converter stuff, paint and waxoyl, to keep it solid for it's next owner.

It's a shame the underside is so crusty as I even keep the engine bay gleaming...
IMG_20231106_201612_553.jpg
...and that was me just about to set to cleaning it up :-D
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c16rkc
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by c16rkc »

Galvanic corrosion - so which bits are aluminium? As far as I could tell all the brackets and fixings are mild steel.
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MattBLancs
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MattBLancs »

It's obvious from your pictures that you do take good care of the cars, but the corrosion is trying it's best to undo your good work!

Like you say, they seem to quickly get a little crusty, fortunately I've not yet heard of any structural corrosion issues so hopefully it remains a visual problem and not progressing to something worse. :)
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MattBLancs
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MattBLancs »

c16rkc wrote: 08 Nov 2023, 22:07 Galvanic corrosion - so which bits are aluminium? As far as I could tell all the brackets and fixings are mild steel.
Loads of bits when you look:
Front and read subframes,
Power steering pipework,

The front lower wishbone and FRIP are steel, but then the next part is aluminium,
Then the swivel hub (carrying wheel bearing) is steel again.
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MattBLancs
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MattBLancs »

The spheres are steel, but the rear centre ones are into an aluminium block.

Another aluminium lump to form a connector for two steel hydraulic pipes nearby too.



Good memory test that! Nothing else coming to mind at present but it's been a long day!
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by Jay-Bruce »

Good going with the list there Matt, but I'd add the steel calipers bolted to aluminium hub carriers to it as well.
MrBerlingoC5
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Re: C5 (X7) 3.0HDI - suspension pump brushes and height sensors

Post by MrBerlingoC5 »

Hi guys, this thread also reads like a fine Greek epic :) Did the remanufactured brush assembly (826.012577) ever get more research from anyone?