FDV : don't just swap it, overhaul it !

[ianselva]

Any other symptoms of pump failure I could look for , I changed it last year but only for one off another car.

[cauchoiskev]

Why did you change the pump ? Were there steering problems before the change ?

Oh, and is the pump belt really tight ?

[ianselva]

I had a spare one and thought it might cure the problem , but it made no difference at all . it wasn't a new one but surely the chances of another one showing exactly the same symtoms must be small . You'd have thought it would be better or worse but no change at all . The problem hasn,t appeared again since the weather got warmer. There seems to be two opinions on the problem FDV or Pump . What I need is a definitive test for one of them.

[jeremy]

Its perfectly possible that your second pump was defective - after all someone has discarded it havent they.

If the thing is ok now then the FDV is probably OK.

When the car rises does it leap into the air or do you have to wait and wonder if anything is ever going to happen? If its the latter then the pump has gone.

What seems to happen is that the pistons cease to return due to spring failure. Gumming up is always possible and flushing with the special fluid may ungum things.

Of course all sorts of things happen if air gets in before the pump. The condition of this hose and its end connections is vital as is an extremely tight drive belt.

[cauchoiskev]

You can always clean the filter at the top of the FDV without taking it off the motor (don't forget to let out the system pressure). It's the pipe on the left hand side as you look from the radiator. Underneath is an allen screw (5mm), although you won't be able see it as the hole will be full of LHM. Unscrew it, then you can get the filter out with a suitable blunt intstrument, about 1/4 inch wide or so at the end. If it's full of gunk, or completely exploded, as mine was, this could be your problem.

Honestly, I doubt it, but since this is a fairly easy job to do...

[mikael]

You can always clean the filter at the top of the FDV without taking it off the motor (don't forget to let out the system pressure). It's the pipe on the left hand side as you look from the radiator. Underneath is an allen screw (5mm), although you won't be able see it as the hole will be full of LHM. Unscrew it, then you can get the filter out with a suitable blunt intstrument, about 1/4 inch wide or so at the end. If it's full of gunk, or completely exploded, as mine was, this could be your problem.

Hi, Thanks for a excellent description of an FDV overhaul.

I have intermittend PAS and plan to try out the procedure, but wanted to check the top filter first before I went to Cit' for spares.

I removed the pressure pipe, found a nice clean 5 mm allen key in the toolbox, but to my surprise the allen key did not 'bite', found a 6 mm with the same result, I'm allmost certan that there's no allen key down there on my FDV.

It's a bit hard to see with the valve still mounted on the engine(and lhm dripping out), but it looks like the filter is held in place by a steel ring pressed into the valve instead of the threadded allen version.

Has anybody here seen this type of inlet on a fdv before?

Thanks in advance.

Regards.
Mikael

[jeremy]

I have one of these on my BX TD. The filters are in fact steel cones with holes drilled in them - and so don't get destroyed like the plastic ones do!

Mine was defectively assembled and caused all manner of problems - as the warning light would come on at speed! The cause was that the system pressure relief valve which governs the pressure for the whole system was at fault. It is a ball bearing valve and the sequence should be ball, support plunger, spring screw - and on mine the ball and the plunger were the wrong way round so the thing was trying to seal on the plunger! (Took for ever to find and really only found it by luck!)

The PAS worked perfectly at all times when I had a new pump on it - not really before except with new LHM. Had I rectified the valve I may have saved myself a pump - but knowledge on these things was much less 7 years ago.

Incidentally this FDV is painted black not green.

[mikael]

Incidentally this FDV is painted black not green.

Mine is black too, dismantled it and cleaned what could be cleaned thru the plugs on the sides.
Apart from the filters everything is exactly as described by cauchoiskev

Heres a picture of the 'non allen key' inlet port:


To me the filter looked like a regular plastic filter.(I might be mistaken, It's hard to get a good look at it. )

The filtered inlet on the bottom of the valve is fitted in the same manner and I found no way of removing the discs and piston behind it. (Had to rinse it thru with petrol without removing it.)

The PAS is now smooth and I hope it stays this way.

Regards.
Mikael.

[cauchoiskev]

Unfortunately the colour of the paint can not be used to distinguish between the types of FDV : mine had plastic filters, but was painted black as well !

I have also heard of these pressed-in filters, which seem to have been fitted to some - but not all - of the later models.

[kiwi]

How typical just got a price for the FDV seal Kit in New Zealand

$140.97+12.5% GST.

Not really a shock just find the price from the UK times it by 2 like everything else

Reckon you donr the maths by now thats sixt three quid.

[citro-geoff]

A while ago I had an intermittent problem with the power steering on Hayleys BX RD turbo. Some times when she drove off,the steering would be fine,and after a while when turning a corner it would stiffen up. The end result was quite frightening,although she got used to it. She didn't tell me for a while,and I only found out when I drove it. The problem turned out to be a knackered pump. Chris Jacob overhauled it for me and had to put new pistons in it. Another symptom can also be the pinion valve on the rack when the seals break up and get into the pipes and partially block them,although when this happens they valve tends to weep.Chris is still overhauling pumps,but mainly to order. He has just done one for me for my friends V6 Xantia and what a pig of a job it was too!!

[Jaba]

I have recently serviced my FDV as the side plugs were leaking.

I didn't get the repair kit as the filters were ok and I found that aircon hose o-rings, size 8 fitted the plugs exactly. As I had some of these in stock and they are a low cost and easily obtainable item this method might help others to do a low cost repair.

[Aerodynamica]

I have recently serviced my FDV as the side plugs were leaking.

I didn't get the repair kit as the filters were ok and I found that aircon hose o-rings, size 8 fitted the plugs exactly. As I had some of these in stock and they are a low cost and easily obtainable item this method might help others to do a low cost repair.

That's quite good info to know as it's more often the O rings that need doing than the filters innit.

But is the rubber compatible with LHM?

[Jaba]

But is the rubber compatible with LHM?

I have made the assumption that it is. Aircon systems circulate both mineral and synthetic oils at high temperatures and pressures - up to 25bar. So these are not water plumbing grade o-rings.
Time alone will tell of course.

[TB2]

Does someone know if GSF still sells these kits? I searched their shop but couldn't find anything. entering the part number (N43444A) didn't turn any results.

And btw, is this for real, they're selling the hydraulic pump for just 270gbp? That seems very reasonable. Maybe it's an overhauled unit? GSF Part number 434PC0390. I heard these are like 500gbp upwards when new, aren't they?