Citroen C5 x7 hydraulic leak

[MattBLancs]

Nice tough paint sounds good. No experience of it so I'd have guessed caliper paint would be something like VHT paint (which has never struck me as a particularly good paint!) So interesting to hear it's nice tough thick stuff instead.

My "cleaning up rusty components on the underside" paint of choice is cheap gloss / mat black from the builder's merchant. Not that I think it's particularly resilient, more it's cheap and I can slap it on anything and everything I feel the need to paint! Can't stand crusty rusty corroded components, does slow me down fixing stuff when I pick up repainting jobs along the way!

https://www.cwberry.com/blackfriar-matt-black-paint

Matt

[KennyW]

Graeme,

I'm thinking of using a standard bubble flare with an adapter to fix any future problems. It worked for the front to rear suspension pipe.

Kenny

[Jay-Bruce]

I'm working on the supply problem, but need a little info from y'all - are the threads on both the little short pipe with the rubber hose the same on both ends? Are the pipes on both sides of the aluminium union the same thread / end? Is the fore to aft suspension pipe the same ends on both the forward end at the BHI / "pump" as it is where it goes into the aluminium union?

[aerodynamica]

I'm working on the supply problem, but need a little info from y'all - are the threads on both the little short pipe with the rubber hose the same on both ends? Are the pipes on both sides of the aluminium union the same thread / end? Is the fore to aft suspension pipe the same ends on both the forward end at the BHI / "pump" as it is where it goes into the aluminium union?

Hi, yes the short pipe with the rubber section has the same ends but the pipe at the two way union front to rear has a larger size- the two way straight join steps it down. I believe the front suspension pipe is the same smaller type but it is the same size from the BHI unit to the front regulator, the rear pipe from the BHI is a larger diameter pipe (not sure why? maybe less resistance over its long length than the front)

I'd like to know the thread and length of the screw that holds the suspension strut top pipe flange because I'll need to replace the rear ones.

[Jay-Bruce]

I've PM'd you about borrowing a pipe end to identify the thread to get parts made, once I have the parts for the larger pipe in hand I'm going to replace the pipe, the back regulator, & rear cylinders. I seem to recall the bolts being M10 x1.25mm, but I'd rather double check it, so when I've got the hoses off I'll (re)measure(?) the bolts that hold the hoses into the cylinders, and get back to you with the sizes.

[MattBLancs]

I've PM'd you about borrowing a pipe end to identify the thread to get parts made, once I have the parts for the larger pipe in hand I'm going to replace the pipe, the back regulator, & rear cylinders. I seem to recall the bolts being M10 x1.25mm, but I'd rather double check it, so when I've got the hoses off I'll (re)measure(?) the bolts that hold the hoses into the cylinders, and get back to you with the sizes.

M10x1.25 is good news if correct, that's standard M10 pitch, so easier to recreate (i.e. standard tap and die set) Some things, e.g. brake bleed nipples sometimes use what can be termed Metric Fine and M10x1.0

If you don't have a set, recommend a set of thread gauges to get the pitch confirmed quickly and easily.

E.g. something like:
https://www.ebay.co.uk/itm/175389200913

Matt

Ignore me I'm wrong - M10x1.5 is standard.

M10x1.0 and M10x1.25 are two variants both can be termed "fine"

Matt

[Jay-Bruce]

Morning Matt, I was about to be anoraky and correct you on the pitches, then I seen the last couple of lines
Not meaning to labour a point, the following information is just being posted for the benefit of anyone else reading this thread* later on.
*thread about threads - unintentional pun

M10x1.5 is, as you say, standard pitch
M10x1.25 is "M10 fine" -
M10x1.0 is M10 ultra fine
A rough rule of thumb is that as each thread size increases it's diameter, it also increases standard pitch one size, for example m6 = 1.0, m8 = 1.25, m10 = 1.50 etc... Another rule of thumb metric fine threads are typically the same pitch as one size smaller standard ie M10 fine is 1.25 pitch - the same pitch as standard M8, and ultra fine threads typically share their pitch with two thread sizes smaller, ie M10 ultra fine is 1.0 pitch, same pitch as M6 standard which is M6x1.0. If you memorise just one standard pitch you can walk your way up and down the tables using those rules.

Thank you for the link, I've already got thread gauges, and have used them to measure up and commission the manufacture of a small batch of parts for producing replacements of the smaller sized ends on the pipe with the hose on it. I've got the first batch of those in my workshop waiting to be test fitted when I swap out the rear firmness regulator, rear cylinders, and associated pipe work.

What I don't have is the luxury of being able to willingly immobilise the car for a few weeks, by dismantling it, measuring up pipework, producing cad models, going through RFQ process, waiting on getting bits machined up, then start reassembling the vehicle. The duchess will be a lot more understanding and significantly less vociferous if I accidentally immobilised her car because the bits I pre-emptively had made didn't fit, than she would be if "I borked it just to see what was in there".

The annoying thing is that from looking at it when I changed the spheres I know that when I put a spanner on our car's fore to aft pipe's back nut, the pipe will break, and thus immobilise the car. This is why I am so keen to get my hands on the remnants of some of these LDS pipe ends to see exactly what is in there, so I can reverse engineer it, and have the bits on hand before dismantling and immobilising her car.

I was actually chatting with my machinist about these this morning, which culminated in me ordering a couple of dozen bespoke pipe nuts, covering the complete range of metric threads that are in the range of what measurements & information I've been able to take myself from our car or gather from forums on these LDS pipe ends. I'm currently out at sea, but these components will be delivered around the time I get home, and I aim to do her car's fore to aft suspension pipe and the back axle hydraulic refresh (firmness regulator and cylinders) during this coming leave period, so the car is proven and reliable for some long distance journeys during our kids October school holidays, enjoying citroen levels of comfort rather than enduring my car's BMW M-Sport suspension' discomfort.

I might as well make the announcement now:
I am developing a setup for home mechanics to be able to make LDS pipes, and aim to be be selling citroen LDS piping kits by the years end.
My kits will not be using glue in adapters like the Russian kit, nor will the be based around compression fittings for splicing old ends to new pipe, but comparable / compatible almost like for like bolt in replacements. And I mean no disrespect to the purveyors of those solutions, they were ingenious, I just prefer stuff I do to be as close to OE as I can make it. As such my fittings are approximate facsimiles of the original LDS fittings, but I will be deliberately making them slightly different to avoid treading on any trademarks / patents / copyright Stellantis (PSA + Fiat + Opel et al) might have on these fittings designs.

[MattBLancs]

Your "in the pipeline" (pun definitely intended ) solution for the pipe flares sounds good, look forward to hearing more as you progress.


I'm in the position of "unintentionally learning" all the pitches so my initial post was from memory. Then the seed of doubt had crept into my mind I had to Google to double check (had it that M12 was 1.5, but that's 1.75 as standard pitch. So, much as you described I walked up and down the sizes but from my incorrectly remembered start point! Oh well, likely will remember it next time round) hence my hasty correction before someone with a better memory/ anorak did a "I think you'll find...." On me!

The exception to the rule is M7 which shares M6 pitch of 1.0
Having said that M7 is definitely what (other than french car makers and Italian - Vespa makers?) Most call "non-preferred sizes" regardless of pitch!

Matt

[ASK_dj]

Anyway, I have finally got the new front to rear hydraulic pipe fully routed from the BHI unit back to the rear suspension Hydractive 3 regulator and I'm happy with that. I now have a problem with the thinner pipe that continues from the straight joiner to the rear regulator. It looks rather rusty and I am thinking it's going to explode at some point in the next 12 months.. This pipe with the part number 55305N is very hard to find! And the only one I found in stock in Germany can't be sent because they will not send to the UK (possibly brexit that I didn't vote for) so I'm stuck. The part number also seems to have changed for later cars because I only see 55305VN or VP and I don't know the difference.. One might be the C6 part number but the diagrams I've seen show a pipe that is identical to mine so I'm unsure.

Hi, I see the post is 2 years old, but how long did it take you to install the pipe from the pump to the rear regulator. Mine surprise me bad yesterday starts leak due to corrosion and I temporarily fixed it. I ordered a new one and see so need rear axle should drop down a bit, the fuel tank too, but the frontside looks a bit complicated. Thanks.

[aerodynamica]

Hi, yes 2 years ago now. It's still holding well. You're asking about the job of replacing the pipe. We'll I'm not going to lie, it's a large job. I think it took me around 1 day to lower the fuel tank, and route the pipe into place. I decided to fit the pipe in position but not to connect it yet. The old pipe had not yet failed but had been repaired in the past by a previous owner using a compression fitting joined just ahead of the fuel tank. I wanted to change this.

I left the pipe in position with a cap on each end for a week then returned to connect the new pipe and then remove the old pipe. This was easier because I cut the old one into shorter parts to remove.

Couple of points: 1. I don't recall having to lower the rear axle. Once the pipe is past the fuel tank (routes above the tank and it's quite difficult because my tank could only be partly lowered) the pipe is free to route to the place under the rear where there is a 2- way joiner. I found the pipe connection to this very difficult to remove but with wire brush, cleaner and wd40, it will unscrew. I think it helps also to remove the rear wheel and wheel arch to at least attempt to help seeing how the pipe goes above the fuel tank. There are pipe clips to locate.

2. The new pipe I got was a full copper pipe and this allows it to be bent easier to route at the rear. So perhaps I had that aspect easy. If you managed to get a genuine citroen pipe it might be more difficult to route it because the shape will be pre formed.

3. There is a difficult part where the pipe travels up at the front with 3 other pipes (fuel I think) and one plastic LDS leak pipe. This part is awkward because there is no space and it's very hard to see where you are aiming the new pipe upwards into the dark.even with torches. You need to ensure the pipe emerges at the top at the back corner of the engine room but not to get tangled in the fuel line, air conditioning pipes and the other hydraulic pipe that leads to the front suspension. There is a specific place for the hydraulic pipe to travel up here.

I think this second stage of fitting the pipe took another day of work but it depends on the facilities you have. I was using a borrowed garage space and I decided not to rush the job because I only wanted to do it once.

Anyway, I hope you can have a go at this and good luck.

[Vladimir1977]

The way aerodynamica solved the problem is probably best and longlasting, but there is one more way to solve your problem, like citroman did...

[ASK_dj]

Thanks a Lot aerodynamica .

[Richard Galway]

My C5 exclusive emptied the entire contents of its LDS fluids all over the ground today and the car sat itself on the ground. I think this is the cause but it looks like a brake line. Am I correct or is this part of the hydraulic suspension?

[xantia_v6]

It must be a suspension pipe, as the C5 brakes don't run on LDS.

[RichardW]

Welcome along!

I would assume it's a suspension pipe - unless it's a power steering pipe. Brakes are separate on these and conventional. Whereabouts is it?