Strange happenings after FDV change

RKM · Post by **RKM** » Sat Oct 18, 2008 6:01 pm

Well, I have owned by BX TZD estate for almost 6-years and she has covered 140,000 miles. Aside from normal servicing, she has not required too much extra and so I decided to spend a few quid on her to keep her running for the next few years.

This has included the fitment of a nearly new radiator, new alternator and treat it to a rebuild FDV, as the stiff steering was driving (literally) me to distraction and making a car, which is normally pleasurable to drive, a nightmare.

All parts were fitted this morning, including some new (and expensive) radiator hoses. Once the car was running and the pump primed, the steering operated wonderfully but the suspension would not rise. The STOP light remained illuminated though and the no ticking or hissing came from the accumulator area. Oh dear.

The suspension only reacts when the steering is moved – the STOP light eventually extinguishes but only just. On a brief drive (on normal height), the STOP light comes on and stays on. Brakes work OK. The LHM level is to the maximum. Any ideas gents?

Sadly, work has stopped play due to a LHM leak coming from the reservoir. Drained the lovely fresh LHM out again to find that the bottom of the tank has rusted out. Fortunately, I have sourced a used one (thanks Graeme), which should be with me my mid-next week.

Any ideas what could be causing the problem? I am on a time limit because, if the car is not running by next week, the scrap man cometh…

jonathan_dyane · Post by **jonathan_dyane** » Sat Oct 18, 2008 8:27 pm

I really hate to say it, but it does sound rather as if your FDV has been incorrectly assembled; did you rebuild your own or source a ready-rebuilt one?

If you rebuilt it, did you use the illustrated guide on here? If not it should help get the bits back in the right place...

Post by **docchevron** » Sat Oct 18, 2008 8:40 pm

Did you prime the pump?

jeremy · Post by **jeremy** » Sat Oct 18, 2008 10:57 pm

A guess - is the system pressure relief valve in the regulator assembled and adjusted correctly?

This is the screw plug arrangement in the middle of one side. If you take it out I think you should have a spring, a plastic support with a cup end and a ball bearing in that order. The ball can be seated by putting it on its seat in the casting (locate with grease if necessary) and striking it ONCE using a BRASS punch. (Steel may put a flat on the ball which won't then seal.)

I had no end of problems with my DTR Turbo and eventually re-built a FDV which didn't work properly (Steering worked but the light kept coming on, went out when steering turned, wheel had to be held against resistance to get car to rise.)

I took the valve out of the original one I'd removed to see what size of brass rod I'd need to re-seat the bearing - and found it was assembled incorrectly - put it right - and re-fitted and its still there 6 years later.

The screw adjustment should not be disturbed - ie slacken the collar a touch, undo plug leaving the collar in position, screw home till collar bottoms, undo centre a touch and tighten collar. This adjuster controls the max system pressure I think.

Workshop manual available in English on Bob Smith's site.

http://www.rwbsmith.plus.com/citroen2/

RKM · Post by **RKM** » Sun Oct 19, 2008 11:20 am

Hi Gents,
Thanks for the replies.

I overhauled the FDV, using the images carefully on this site. I am not stripping he darn thing again! The steering works very well now; just everything else doesn't.

However, my symptoms are the same as Jeremy describes, i.e. the steering works, STOP light on and steering wheel has to be held against resistance for the car to rise. I have no idea why the FDV should be at fault, as I ensured it was dismantled carefully, cleaned well and assembled in the correct order.

Moving to the PR, how would removal of the FDV affect it? Are you saying that, in your case Jeremy, the source of your problems was an incorrectly sealed ball bearing. IF so, may you elaborate on where exactly the ball bearing lives? Is it inside the 12mm pressure release screw?

RKM · Post by **RKM** » Sun Oct 19, 2008 3:29 pm

With a few hours to spare today, I removed the FDV again and removed the plug, which the instructuions on this site say not to touch.

The spring, carrier and ball bearing were clean inside and fitted correctly. I refitted the ball bearing and carrier and replaced the FDV.

Any ideas what else it could be?

jonathan_dyane · Post by **jonathan_dyane** » Sun Oct 19, 2008 3:48 pm

Sorry that you took the thing off to no avail.

As the Doc said, are you 100% that the pump is priming properly? In my last BX following changing the LHM the car absolutely refused to rise, no matter how many times that I primed the intake hose, got an assistant to start the engine, and rammed the pipe back on the reservoir stub.

In desperation I swapped the pump for a spare and the thing primed first time, it rose, and I was rewarded by the steering now working perfectly when previously it had been intermittent. The pump must have been marginal, and just was not providing the suction to allow it to prime as it should.

RKM · Post by **RKM** » Sun Oct 19, 2008 4:13 pm

It may have been worth while taking teh FDV off though - at least I know that the damn ball is seated OK. I have not tried the car since, as the LHM tank has developed a hole!! I have sourced a second-hand one, which should be with me by mid next week.

I am pretty sure the pump is priming, as the steering worked and the suspension pumped up but ONLY when the steering was moved. The pressure regulator was not cutting off though and the stop lights only extinguished sometimes when the steering was operated.

The pump was a good one before, allowing the steering to work fine on the coldest of mornings. The only thing I could think of is that I am replacing the LHM afer the car has covered 2,000 miles or so on hydraflush. Not that much crud in the filters though, as I have always changed LHM after 2-years anyway.

jonathan_dyane · Post by **jonathan_dyane** » Sun Oct 19, 2008 4:14 pm

But thinking about it more, surely if it were not properly primed, the steering would not work properly?

I would try cracking open the pipe which goes between the regulator and FDV and cranking the car; obviously LHM should spurt out.

If it does not spurt, try cracking open the pipe which feeds the FDV, if you now get LHM spraying everywhere then surely the cause must be the FDV? If not you have a supply problem.

It goes without saying that you don't want to slacken pipes while they are pressurised...

RKM · Post by **RKM** » Tue Oct 21, 2008 8:01 am

OK. When the replacement LHM tank arrives, I will give it a try and let you know how I get on...

kiwi · Post by **kiwi** » Mon Mar 02, 2009 5:41 pm

Dragging this old thread up again as it sounds very similer to the problem I am having.

Only differance being I replaced the Pressure Regulator as well which now I have been advised to change the O Rings on of the original and refit it.

First question is does any one know where can find an exploded diagram of the pressure Regulator so I know where these two O rings go before dismantling?

Second Question is for RKM to give an update?