The repair kit is still available and costs about 20 squid in France, maybe a bit more abroad. Expensive for about 10 grams of plastic (although to be honest I was expecting worse). But, when you've done the overhaul,you've got yourself an FDV as good as new ! Well, almost.
Believe me, it is far easier to overhaul an FDV than to put the bloody thing back on the car, which you would have to do if you simply swap it anyway. However, there are a few things you have to be aware of. A French enthousiast has done 3D drawings of all the innards (although I believe he is mistaken on the quantity and posistion of the springs) :
http://www.planete-citroen.com/forum/sh ... hp?t=36437
1) The two filters (one on top, one on the bottom of the FDV) are held in by 5mm allen screws. The bottom filter is inside a metal holder, which itself is sandwiched between two washers with central holes. Here's the state my two filters were in :
Hardly surprising that the steering was intermittent...
2) Once the filters and one washer are out, you need to get the four plugs on the sides out. WARNING ! don't touch this screw :
It regulates the pressure at full lock, and would need special equipment to calibrate.
The plugs are held in by circlips, which look pretty impossible to get out. Here's how you do it :
You just push the plug back against the spring pressure, and then use a small, sharp screwdriver to prise the circlip out. You'll probably think of a more elegant way of doing it, but this worked. You may have to push the plugs inwards to get out the ones on the opposite side.
3) Take the bottom piston out on the opposite side from the filter (left side, where the spring is, as shown below, which is the FDV as seen from the motor)
because, apparently (a French guy says), the other side is not machined, and would scratch the piston. I can't confirm this, but why take a risk ?
4) Now you can get the filter holder out. Underneath it is an unbelievably thin washer (0.2mm) with an unbelievably small hole in the middle :
highly losable, IMO.
5) When it's all apart, wash in petrol. It all looked as good as new, ready for another 300000km ! Buy your kit :
which for some reason contains a double ration of LHM joints. Thanks Mr. Citroën !
Then put it all together again : start with the washers, filters and allen screws. The thicker washer has a conical hole, the wider side :
should be facing you when you put it in.
Then you can put the pistons and springs in and finish with the plugs. You'll have to push them in again to put in the circlips.
6) Now comes the hard bit : putting it back in the car again ! My advice is not to bolt the FDV onto the motor until you've got the HP pipes on (make sure the cable clamps are undone to give some free play). It might be a good idea to take the radiator and even the accu sphere off. As the Citroën workshop manual says, access is "uneasy".
7) Prime the pump, top up the LHM and say hello to sweet, smooth, non -intermittent PAS ! Hurray !
Footnote : there is a common opinion that the FDV was a bodged solution to avoid referencing a new pump. When you take it apart, it looks very carefully designed indeed. It's amazing what clever folk can do with three springs, two pistons and a ball bearing. IMO, this thing will never fail if the LHM is kept clean (unfortunely, few of us have had our BXs from new...) , it will just start leaking as the joints harden. I would also suggest that an FDV will last at least as long as a 6+2 pump.
