aerodynamica wrote: ↑08 Sep 2016, 19:31Hiya, this can be a problem of cars that use the hydraulic 'Flow Divider Valve' FDV in between the HP pump and the Pressure Regulator such as sinker Xantias and PAS BXs and sinker XMs. They fail in a few ways but the main cause seems to be the internal springs going weak alongside a HP pump that's a bit down on output due to age/ miles.of far more corner now is the heavy steering and slow to rise nature in the morning. My cleaning of lhm tank filters etc hasn't helped..I need to get those parts of paul really...i'll message him now..
Are you getting the phenomenon of the red STOP light staying lit for ages in the morning as the thing takes for ever to raise up?
You can do one thing to eliminate the HP pump as the cause for this: Start up the engine from overnight rest, wait say 10 seconds and if the STOP light is still on and the suspension not raising, turn the steering wheel and hold it against its resistance. If while it's being held the STOP light goes out and the suspension starts to go up (even slowly) then it's likely the FDV is duff and needs replaced/ serviced.
It might not be this of course but it's a cause that's exclusive to the FDV - equipped cars.
The FDV is interrupting the HP pump flow before it reaches the pressure regulator and if one of its two slide valves sticks it can sink a lot of the HP pump output back to the LHM tank. There's always an unrestricted flow through the PAS pinion valve anyway but this coupled with an FDV internal leak combines to sink the majority of the pump output. By turning the steering while stationary it makes the PAS pinion valve close the LHM flow the most to the PAS ram which acts to build the pressure that also allows the pressure to the regulator to build (and hence, cut out and let the STOP light go out)
It's a simple check to do when you start the engine to give a minot clue to the trouble.
That aside, if turning the steering while stationary doesn't put out the STOP light then it probably isn't a faulty FDV and might therefore be a bad HP pump or slipping belt.
Hi apologies for the slow response- I never saw the reply and haven’t had much time since taking over the columns.
As per previous post and photos my Xantia has no FDV. To digress slightly my BX does have an FDV but its similar symptoms of heavy steering were traced back to a worn and tired steering ram which given its age perhaps wasn’t too surprising.
As i predicted it was the pump. Luckily the garage I use has a mk1 b TD in. They'd attempted to sell this car but no one wanted it so sadly that car went to scrap- nobody came forward for other parts either. The pump was therefore taken off this car (quite a high mileage car but known to be good 150k I think with a good history) and fitted to mine. At least it allowed my car to live on though!! The issues were immediately rectified and driving it home was a revelation- quick to rise and steering finger tip light. It stayed like this for a bout 6 months.
My car is still going, though again the rising is slowing down though so far my steering is ok- not quite as light but nowhere near as heavy as before. I have kept the old pump but even off the car with a clear inspection it shows no signs of external leak. To me this suggests either worn bearing (I have seen bxs with this issue), some internal leak or some other issue. Perhaps it’s noteworthy that the donated pump had done a similar mileage but was in much better condition…or perhaps this is just a red herring? For the moment it’s quite easy to get hold of second hand Xantia pumps but when these dry up I’m not sure what the solution is.
I will of course try once again to improve or possibly fix the issue with a good tank clean etc when the weather improves.
The Xantia is still going strong however and has hit over 192k now. I still prefer it to a lot of other cars but it certainly has its foibles! Given its age (and the Xantia itself is 25 this year don’t forget!!) perhaps this isn’t surprising.
For anyone interested you can follow the progress of the Xantia and other Xantia news in the column. Though I will of course try to frequent this excellent forum more frequently.
Hope to see you all at a rally this year.
Thanks
Phil