Hydraulic system woes (2024)

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#77713

David.

On 8 Feb 2015, at 18:11, andrew.fulcher@... [DSeries-L] <DSeries-L@...> wrote:

Started my LHS2 DS19 today to shuffle it across the garage. After driving a few metres, there's the familiar large puddle of suspension fluid underneath...

It looks to be coming out somewhere towards the centre of the car, just behind the front wheels. Peering into the engine bay with a torch, it's difficult to see any signs of catastrophic leakage, although I think there's some wetness around one of the accumulator sphere pipes.

Therefore, a couple of questions:

- I'm thinking that something must have let go around the accumulator sphere / pressure regulator, judging by where the fluid's ending up (LHD manual car, so the accumulator sphere's bolted low down on the side of the engine). It's a pain to get at, though, so wondered if anyone could think of anywhere else it could be coming from? Think it's too near the centreline to be height corrector or suspension unit, an d too far back for brakes.

- Assuming it's the pressure regulator, I'm thinking that it might be a good time to relocate it at the same time as fixing the leak. Good idea? Any pointers?

Finally, I'm contemplating whether this might be a good time to switch to LHM. It's realistically easier to get at the accumulator/regulator with the wings and radiator removed, at which point the steering rack and front brakes are that much more accessible. I've already rebuilt both height corrector with universal diaphragms, ditto for one of the front suspension units, so am part of the way there. Anyone have any insight into how much work is required? The car's a '64 manual DS, so power steering and brakes, but conventional gear change.

Andrew

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On 2/8/15 3:29 PM, Roger vise Europutt@... [DSeries-L] wrote:

You should consider relocating the main . I prefer the the right frame rail. Steve sent me the parts at a very reasonable price. He should be able to do that for a brake fluid car also.
My first Citroen was a 1962 ID19 wagon. It is still my favorite. It was our main car for 4 years . I put a 1966 id19 engine in it and a few mounts later first gear failed.
I've had Citroen wagoner ever since that one in 1980.
Your leak is most likely the big hose . The bend gets stressed.
Be sure to find the line junction to make it easier to get that main unit out of the hole . Comes bracket and all out the top.

In my opinion if the brake fluid system is mostly good than just fix the leaks.
If you change your fluid yearly and check and clean the filter regularly . It works fine.
I do believe it gets dirty and the filter needs to be checked. It makes everything work harder when dirty. I've seen it need it in 500 miles on a car that had sat.
Brake fluid of this type will draw moisture out of the air. Has poor particle supendtion so the stuff settles out when it quits moving. It also has no lubeing effect.
I believe that straight brake fluid will work fine most of the time. Castor bean oil will not hurt things like WD will . I have lubed old rubber parts with no problem.
If a pint in the fluid tank on change day.
Helps keep the debris loose and maybe lube the moving parts it sounds like cheep insurance to me.
The old man Howard in Palo Alto who sold me that first ID told me to do that. He had owned the car since new. I always did.
The other thing is ride. A brake fluid car has The best ride compared to both the 1966 wagon and the 1972 Wagon . That I have had since . I do not know how much is the fluid but brake fluid is much thinner feeling than the Dextron my 1972 is on the last 35 years.
Roger
Lower Lake,Ca

Citroen Worlds Most Exciting Car

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Posted by: Roger vise <europutt@...>
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#77736

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#77740

I'm aware of the dangers of high pressure hydraulics Peter, which is why I always ask for supplies from a professional hydraulics shop that have at least a 3X safety factor on pressure rating, I use a stainless steel over braided Teflon flex hose for the line from the pump to the regulator, as the Teflon is compatible with any fluid, and I also specify steel high pressure compression fittings for joining the original line ends to the hose. What's dangerous is where some owners have simply rebent the steel line to go over the steering rack to the front-mounted regulator, and that approach may very well cause fatigue cracking of the 1/4 in. line from engine rocking. I've only had two cases in 52 yrs of lines leaking catastrophically - one of the transmission lines in the bundle of 5 pipes going to the gearbox on my '65 DS19 Citromatic rusted thru, and sprayed DOT 3 in a manner I'd never seen before - all of a sudden I saw a fog coming out from the left front wheel well that made me thihk the car was on fire, it was just like smoke! Turns out the pinhole leak was so tiny it perfectly atomized the fluid to a smoke like consistency, but fortunately was buried below the brake caliper. It was thru that event that I learned the mechanic the PO had taken the car to had bundled the pipes so tightly they created a water and crud trap atop the bundle. Since then I always spread lines apart so they don't create gravity traps for junk. Last big failure was a fatigue crack in the big line on a ;70 D Special with original pipe tied down in original location, across top of trans, to stud on bell housing hiding behind LH park brake caliper, then down to regulator. I had been playing Lowrider during a huge classic car show in Detroit where annually 30,000 hotrods and a few classics show up, and of course the kids love watching the Cit rise & fall - but the line, with zero rust, evidently had a flaw it it as it cracked at a totally stable, fastened down position from the factory - it literally split axially as tho the thin sheet metal wrapped and furnace-brazed line had a defect. And of course the anchor clip behind the park brake caliper is impossible to remove without removing alternator and the caliper, the car went home on a flatbed. So I had a perfect excuse to relocate it. I

I may have been the first person in the US to relocate the regulator, as I grew up with my father's '58 DS19 Citromatic in the middle of nowhere, with no service. And that car had the front-mounted regulator. So while a graduate student in engineering in the '60's, I redesigned the regulator installation, built my own pump rebuilding tools and a regassing rig using junk from the Mechanical Engineering shop, and re-engineered the heating system to keep from freezing during the -20 F winters in Chicago - all this on a '59 ID19 I had driven cross-country from Los Angeles to New Jersey and back to Chicago on its single piston, non-power brake, non-power steering system.

I agree completely with you on the danger of messing with high pressure hydraulics, which is why no one but myself works on my cars - I've seen some horrible bodge jobs on these cars and had professional mechanics screw up my own American cars. No one without a thorough appreciation and knowledge of the physics and the dangers of pressure systems should make parts for their Citroen hydraulic systems.

As an example, I was hired 6 yrs ago by a very wealthy owner of the world's largest collection of military vehicles to repair the hydraulics on his 1965 Mercedes 600 limousine. Strangely, all the windows, door latches, bootlid lift and lock system, rear seat movement, chauffeur's window, and vent doors were hydraulically powered! But when the system of control valves for the windows on the driver's door started leaking an LHM type fluid, he was unable to close the windows nor really use this very expensive car. He had taken it to a so-called Mercedes expert close by to have him fix the system, but that man failed to do so in spite of what he charged Jacques. When he found out I knew Citroens, he had me tackle the car. I built a test rig to evaluate the single piston pump output, using nothing more than a hand crank I made on the pump pulley and a pressure gauge. Where the Mercedes manual said the max regulator pressure was supposed to be 2700 psi, my gauge said it was putting out 3700 psi! That shocked me, as I couldn't understand how a "professional" had missed this, but also came to believe he had shimmed the regulator blowoff valve to a higher pressure himself in some mistaken belief this would fix the leak, when it is probably what blew the window switch seals and made things worse. I simply removed a shim to bring pressure down to factory spec, replaced his blown Bosch accumulator ($7000 from MB) with a Parker free-piston accumulator of same size I had custom-pressurized ($350) and adapted the fittings to the different ports of the Parker, plus installed two fluid-damped pressure gauges - one in the engine compartment so the system could be checked without invading it, and one below the dash so the driver could always know the overall system pressure at any time with a glance. That fixed the $100,000 car at a far lower cost than the MB dealer.

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You're welcome - hope these help others -

#77801

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Andrew, the 4.5 mm tube equates to 3/16 in. roughly, and I use standard 3/16 in. OD standard steel replacement brake lines to replace the original Citroen lines. Here in the States these are available in various lengths at any aftermarket auto parts store. To replace the Citroen fittings, I simply use a tubing cutter that tightens around the tube, and you roll it around gradually tightening the tube more and more until the thin blade parts the tube. I cut the Citroen end fittings off as far back from the flare as I want, then couple the Cit fittings to the 3/16 in. lines with a steel compression fitting bought from a hydraulics shop. I save all Citroen hydraulic end fittings this way, to make up new lines to replace rotted ones. You need to make sure to tighten the steel compression fittings enough to swage the small double-tapered ferrule onto the line tightly, and to improve the seal and grip, I use blue Loctite. I put the coupler cap over the tube, put a drop of Loc. on the tube end where the ferrule will sit, slide the ferrule over the tube so it also slides over the Loctite, then tighten the coupler to whatever is recommended by the hydraulics supply shop. Then I separate the just tightened parts, look at the ferrule to make sure both tapered ends have been tightly compressed against the 3/16 in. steel tube - which is slightly smaller in diam. than the 4.5 mm tubing - then retighten firmly, but don't overdo it. The swaging of the ferrule down at its ends slightly crushes the new/old tube, making it very hard for the line to push out of the joint, and the Loctite seals any small corrosion pits on the old line (clean it first by twisting fine scotchbrite nylon abrasive pad around tube end, or wirebrush it.)

If you do the calculations, the force trying to push the tube out of the compression fitting is approximately 70 lbs axially at 2,500 psi pressure, so if the coupling is tightened properly, you should be able to hang, say, 100 lbs from the end of the tube without the joint separating. Anyone using this method to make up a new line must have a good feel for how tight the coupling should be as it's very difficult to put a torque wrench on this joint unless you make up a test piece with a very short end on it for a socket on a torque wrench. Better, if you can hang your body weight from a joint made up this way, the joint should be safe. You might say I've pushed or tested this method further, in the sense that I use brass compression fittings from the hardware store, and brass is not as strong as a steel fitting of course. Is it safe? Anyone using this method must decide that for themselves. It has worked for me for 52 years, during which this coupling method has never separated on me, on any car. I've had a couple minor leaks - sealed by either tightening the coupler more at the leaker end, or separating, degreasing, and putting a bit more Loctite on the ferrule and retightening.

So on long road trips away from home, I carry several compression couplers and a tiny tube cutter. This kit has saved me several times when a rusted line has pinholed and is leaking like a sieve. I also carry a 9 mm crowfoot wrench to undo the line nuts. Once the nut is broken loose, the crowfoot can be spun easily by hand much more quickly than winding the nut out with an open end wrench, and reinstalled the same way.

A 14 mm crowfoot is also very handy for loosening/tightening the speedo cable nut behind the speedo - its open end slides over the cable, then will hang on the nut, engage the tiny ribs on the cable nut, and stay in place for blind manipulating inside the dash and snug tightening in its miserably tight confines.

The crushing of the ferrule, done right, actually reduces the OD of the tube, and interlocks the ferrule with the tube, such that any force trying to push/pull the tube out of the ferrule has to be very high as the coupler then becomes like a draw-die - it wants to shrink the tube continually as the force moves the tube thru the crushed ferrule. And a draw-die takes very high forces to accomplish this. I always make sure I'm well away from any newly-made joint when I pressurize the car's system, let it cycle awhile, then check for leaks. Then do a bit of road-testing in a safe area. The advantages of the compression fitting are - they're easily available, new steel lines are available everywhere - all you have to do is bring a couple extra original line ends with their flare and line nut, if the original isn't salvageable. Always make sure to depressurize the system first, and wear safety glasses when working around hydraulic lines.

Ken

#77804

Andrew, which line leaked? The 3/16 in. line (4.5 mm), or the 1/4 in. line (6.4 mm)? Any hydraulic shop can make you a custom 1/4 in. line from pump to regulator, using braided stainless wire over a Teflon core, with end fittings consisting of 1/4 in. STEEL compression fittings good for about 3000-5000 psi (ask the shop the pressure rating of the compression fittings). With one of these, which in the states costs about $20, you can couple the original large pipe ends to this flex hose and locate the regulator any where you want. Again, tightening the compression fittings properly is a must...................

Ken

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Roger, any hydraulics shop sells the steel compression fittings made by Swagelock or others, and it's a common part. Plus hydraulics shop stuff is designed for high pressures, in forklifts, jacks, backhoes, etc. I realize what I do is a little unkosher, but my background is physics, and I design accordingly. I've seen really bad stuff done by the so-called professionals, in many different fields, so I trust my stuff more than theirs. But I don't recommend doing things like I do unless one really knows the physics of the application. And of course I always test my results on myself. As for the professionals, I've just learned how bad Ford Taurus rear springs are - they tend to crack, and become a can opener for rear tires, causing instant massive blowouts when the broken end slices thru the entire sidewall of the rotating tire in a split second - check out Utube. I did a lot of work with Ford Engine engineers, and they were ok, but whoever specified their rear spring construction missed something or the supplier was the really low bidder!

So much for the professionals -

Ken

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