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Discussion Starter · #1 ·
Hello All,

The recent failure of the fuel pump on my car rearranged my "what's getting fixed now" order at that time. I'm looking to get back on track with rebuilding the accumulators and accumulator control valves.

One new behavior that has developed since I replaced all of my hydraulic hoses is that if the car is allowed to sit for a couple of days the hydraulic fluid is definitely being pushed back into the reservoir such that it is above the respective "full" lines. This is more pronounced for System 1 than System 2. Of course, that means both brake system lights will light up upon start when this condition occurs.

I am presuming this is likely secondary to an internal leak permitted by the accumulator control valves. However, I know that it is possible that it's something else.

Should the accumulator/accumulator valve rebuild be the most likely fix for this, or should I be adding some other section of the hydraulic system for repair/rebuild as a more likely culprit?

Also, if anyone happens to know of a source for an AS568-003 square cross section o-ring in EPDM or AFLAS let me know where they can be obtained. I've had no success lately in finding a US source, unless I want to have them custom made, and it's the only seal I'm missing to rebuild my accumulator valves.
 

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Hi Brian,

For me, what you describe is completely normal. It's the same thing for my 86 RR and 97 Bentley, and all my hydraulic Citroën cars except the last models, because they have a new hydraulic circuit which sidestep this enfeeblement


For your o-ring you probably can found them at Citroën garage, since the regulator/conjonctor/accumulator come from their factory for SZ séries, I'm sure, but for SY séries, I don't know.

regards
Bernard
 

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The following all provide ways for the accumulator charge to end up back in the reservior:

1) A leaky piston in the accumulator valve
2) A leaky accumulator non-return value + a leaky hydraulic pump
3) A leaky height control valve
4) A leaky brake distribution valve

Is the car parked outside? I wonder if wind loading is enough to cycle the rear height control. Going up and down (even a tiny bit) would also result in the fluid moving from the accumulators to the rams and then back to the reservior.

All armchair musings, however. Haven't dug into the hydraulics myself yet.

-- Jeff.
 

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Discussion Starter · #4 ·
So far I'm mostly getting a "this is normal" vibe from various sources, but I'm very confused as to why this did not occur in the past. Maybe I accidentally fixed something/opened some path not previously open when I replaced my hydraulic hoses last year and this is the result.

I really suspect that something is not quite right with the accumulator control valves since the speed at which this is taking place is so different than what it had been in the past. Since I have to rebuild those we'll see what happens once they're done.

I've made contact with a Citroen parts seller here in the US regarding the availability of an AS568-003 EPDM square ring. In this case, I know it's not an O-ring "gone square" since it comes in the Crewe kit with a square profile. I've been able to source all of the O-rings and Quad Rings for the height control valve rebuild kits and brake pump reseal kits in Shore 70A hardness EPDM. I've also put together the entire seal collection for the accumulator control valve with the exception of that one, tiny square ring.

Brian, who may end up spending the $60 to have 500 of them made so that I can complete the collection of now incomplete accumulator control valve seal kits I have
 
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