Pressure regulator has lost its tick

[RobC]

Hello and welcome. I'm worried you might be over-analysing the pump thing and it could be a red herring.

Could the problem not simply be the ball valve needing to be reseated in the pressure regulator? Maybe the little ball bearing even fell out during your work.
Also I remember having exactly the same symptoms when I replaced an engine and put everything back together. Lots of repeated bleeding of the 12mm bolt and plenty of lock to lock steering, allied to sustained high engine revs at 3,000 or so, and eventually she started ticking normally.

I could be entirely wrong of course.. Things are never simple with BXs

Bonne chance!

[awatt_bx19rd]

Hi BX Bandit, it's a 6+2 for sure, and it's mounted below the alternator. On the 2 side I removed both pistons and plugged the output, so nothing is happening there and that side can be ignored. I ran a pipe from the 6 side's output, directly to the inlet port of a regular BX FDV with every other hydraulic part such as the regulator being a standard BX item. I hope that's clear.

Thanks RobC, I can't see what could've caused anything in there to come unseated and no ball bearings have been lost. A fair amount of bleeding has been done as you describe. The steering has traveled from lock-to-lock more than 10 times.

It sounds like the pressure's properly building and is about to click, but just doesn't! Are there any advanced tricks that sometimes become necessary for system bleeding? This morning I will show it yet another session of bleeding and lock-to-lock action for good measure. Following that, I will look into reseating the ball valve you described.

[BX Bandit]

I hear you with the power steering matey, got the same problem there and mines a standard setup.

The only procedure in the citroen workshop manuals is this, not that I've ever done it this way!

Loosen pressure reg bleed screw
Fill the pump with fluid via the feed pipe
Start engine
Quickly connect suction pipe (to the reservoir ) when he pump seems to be priming
Tighten pressure reg release screw when pulsation is felt in the return pipe (of the pressure reg)

In the case of removing and replacing an fdv or pressure reg it just says to screw out and screw in the pressure reg release screw several times.

Note that oil continually flows through the fdv and pinion valve and mostly self purge, but if you've not disturbed them or drained them of oil then you should have no issues.

I understand what you've done now. The other bit of info is that the bx pump puts out 4 cm cubed of lhm per rev.

[BX Bandit]

Well, RobC has mentioned what I've decided to try next. That is, with engine running and on low suspension, open and close the pressure reg relief valve several times.
When you think about it, any air in the pump will go straight to the fdv and then to the pressure reg.
In cit work shop manual, if replacing either of those two, the above procedure is the one mentioned.
You never know! I'm sure you'll know this but best be safe, don't be under the car with it on high and release the pressure reg screw!

[awatt_bx19rd]

Edited. See new response below...

[awatt_bx19rd]

Thanks for the info, BX Bandit.

I've released pressure at the PRV while in service-low multiple times and it's still not clicking.

Another observation: Is it considered normal for the pump to come under more strain (idle becomes lower) as you drop the suspension, and for the pump to come under less strain (idle becomes higher) after suddenly shifting the lever into "service high" to raise it?

[BX Bandit]

no! The only time the engine will labour any is when the prv is releasing, during the pssssssssssscccccchhhhhtttt-tick as Rob C mentioned in my post.

[awatt_bx19rd]

Okay, well, clearly the supply pressure is becoming too high, backing up in the system and causing the belt to slip on the serpentine belt. So there's nothing wrong with the pump then.

The regulator has to be jammed or somehow seized in my mind. I guess it will have to be pulled off for disassembly and a clean. I just hope it's relatively straightforward!

[BX Bandit]

The revs should be unaffected when the car drops, as it's all return circuit and isolated from the pump.

[citronut]

The regulator has to be jammed or somehow seized in my mind. I guess it will have to be pulled off for disassembly and a clean. I just hope it's relatively straightforward!

i saw a case years ago were a cit service agents i worker at hired a newly trained/qualified F*O*R*D mechanic,

the first job he was given was to fit a new clutch to a GS, he was told if he required any help not to hesitate to ask,

on key turning ceremony the car was started up, withing a few seconds there was a load bang and the accumulator sphere split wide open,
my bosses son check out what had happened, fitted a second hand sphere this also split wide open,

so he swapped the regulator and all was well,

he then dismantled the old regulator to find tinny specs of pipe seal had blocked the way of the hydraulic pressure,
which built up in the wrong place splitting the sphere open

regards malcolm

[BX Bandit]

Wow, that's some going to split a sphere open! I bet the Ford bloke shat himself for a bit!

[citronut]

Wow, that's some going to split a sphere open! I bet the Ford bloke shat himself for a bit!

and the G only has a single piston pump

regards malcolm

[mark connolly]

have you fitted a new sphere to the regulator.usually when the regulator does not tic its the spring inside has broken or gone weak. replace the regulator if it has. also have you cleaned the suction filters in the lhm tank. 2 filters reside there .dont just look at them clean them they sometimes look clean but have a dirt film across them.hope this helps.

[awatt_bx19rd]

Well, I dismantled and thoroughly cleaned the regulator. Here it is:



I refitted it to the car, started the engine, bled and topped up the system as necessary. After all that rigmarole I could not observe any change in behaviour at all.

So... now it seems that the only option I've got is to put a pressure gauge onto the regulator output in order to prove that the pump's output is falling short of the required 170 bar.

Hmmmmm... I'm not really convinced that the pump's pressure could be so low, because even at idle speed the car always jacks itself up like a boss as soon as you shift the height lever... Having said that, the power steering is still absent... but then again, a lack of steering assistance would usually be attributed to dicky steering gear/FDV issue, right?

Thoughts, anyone?

[icrc]

hello...
IMO...the Xantia 6+2 pump, the 6 piston feed steering and the 2 piston feed the suspension and brake...

and the 6 piston way has a limit pressure to keep steering safty when you turn to dead point...so if you use 6 piston (now you reduce to 3...)
the pressure will not reach to accuracy pressure of couse...

so your regulator will never tiiiick.....