Ongoing Hydraulic Issue

[kiwi]

To summerise many months ago had a bit of a dribble so replaced the FDV with a spare I decided to overhaul first! This didnt cure the leak so replaced the Regulator with another spare.

Leaks Cured......But

Had a strange noise from the power steering and the warning light would come on and the chracteristic pressure click was missing! Seems as though the car would pressurise at start up or under severve braking etc

So replaced the Regulator with the original which we replaced the two o-rings in! OK you would think problem solved?

Nope! Took the car for a drive and yes the light came on again but not as bad as before it seemed. Yet it still came on! Coming up the drive noticed the smell of LHM and there it was peeing out the FDV joint to the large pipe that goes to the regulator.

How is a mystery to me of that joint coming undone!

Well now the Power Steering is none existant!

So does that confirm what suspected all along? The FDV that I replaced was faulty or I buggered up on the rebuild?

[DLM]

Erm...to be a bit brutal I don't think you'll get anywhere too quickly by speculating how you got to where you are. Maybe the original problem or the second-generation "solutions" could have caused what's happening but I wouldn't count on it. First thing to do is find out whether the leak comes from and fix it. Two possibilities from where I'm standing are:

(1) A pipe seal that's expired
(2) A stripped thread on the hydraulic junction (I hope not for your sake)
(3) A pipe that's expired

On an HP pump I once had to replace an output pipe which had been under too much stress and sheared at the level of the top of the screw-in pipe nut where it enters the pump. Maybe something similar has happened here. Though I could see LHM flowing very freely from the general area of the pipe nut, I unsuccesfully replaced the seal a couple of times before realising the pipe itself had started to shear at the very level of the top of the nut, and piddling about with the seals was doing nothing to remedy the problem.

Maybe this is the kind of thing that's happened here if you've had to bend pipes during removal/replacement?

To also be a bit pedantic, the pipe you're talking about is going FROM the PR to the FDV rather than vice versa, as you described it. You probably didn't mean to imply that flow was going from FDV to PR, but it reads that way.

As the FDV channels the hydraulic pressure via its valvery to whatever is demanding it, it's hardly surprising that the steering wasn't working as the steering loses its #1 priority for flow diversion if the input pressure drops, if I'm correctly remembering the way the system degrades under low pressure.

[kiwi]

Sorry DLM I think your on the wrong path as well

Problem started after replacing the FDV originally. Which was not the cause of the dripping and probably a wrong direction then because I was under the impression from this forum that the accumulator/pressure regulator would not leak form the opposite end of the sphere.

This part proved wrong the regulator was leaking! so got replaced.

So the problems I have been having probably have got masked by the belief the regulator at fault and not the FDV. The pipe that leaked was a loose union which possibly I may have inadvertantly loosened.

Note! No problem except small leakage prior to this work.

Can someone answer these basic questions

What would cause the Regulator not to maintain pressure?

How much influaence would a faulty FDV have to it?

Im kind of stumped with this the easy way out would be to either give up or swap the two componants with the other working Hydraulics on the other BX. Given the BX with the issues is a head replaced TZS with Air con over a 19TRS with a leaky sunroof and twice as high mileage. You can see my reluctance maybe?

[jonathan_dyane]

Don't be too quick to dismiss DLM's wise words. Your first task is to identify *exactly* where the LHM is peeing out of, and to repair that leak. Only after this pressure leak is resolved may meaningful diagnosis begin.

[kiwi]

I havnt dismissed anyones words I have pointed out that the leak that was "peeing "out was located and fixed.

The problem is isolating which componant is causing the problem! Thats what I am trying to isolate.

I noticed another thread on here that related to a problem following the FDV refurbishment and replacement and suspension issues there after. So lets clarify

A, Power Steering has gone Heavy

B, Noise evident from power steering eg turning the wheels.

C, Suspension rises but the regulator dont seem to be maintaining pressure or basically needs a shock to function properly eg turning engine on then off again or severe braking manuaver (not sure of the relevance of last?)

[kiwi]

Well its FIXED

Today took the step of basically putting back what was there before in so far as replacing the FDV with the original. Well that was the plan until whilst cleaning them up noticed by fluke more than anything that one of the filters was not in the right way up on the one that was in the car that had been reburbished.

On checking the second filter you guessed it both upside down

So I took a gamble and put the FDV back in rather than risk the original I knew that leaked.

Well blow me after topping up 2 ltrs of LHM after yesterdays blow out the problem is fixed. Just got to watch out for an union leaks but as far as can tell its solved.

Simply mistake of fitting two tiny internal filters upside down and look how many theories it threw up! Guess compounded by the dribble from the Regulator.

OK whats next

[DLM]

I'm very pleased to hear it's all resolved without further head-scratching. you didn't say that you'd already sorted out the leak described at the top of this thread so that's why I assumed it was the first thing to get sorted out.

[kiwi]

I did

3rd Line first post

anyways its fixed and certainly a word of Caution for anyone doing a FDV overhaul to check , check, check and re check.

Theres another topic here where someone else had the same issues after an FDV change. No doubt many others could of reached the the level of frustration that would have scrapped the car.