Lack of power steering

[BX Bandit]

Right then, I still NO power steering. I believe all was mechanically sound before I got the car, so it must be something either due to storage or me being an idiot.

I've not touched anything at all to do with the steering. The only thing I've done hydraulically is remove front struts, bleed the brakes and erm, start the car and run it for 5 seconds max with the filter assembly out of the reservoir. So I imagine air is in the system, but aside from bleeding the brakes and citerobics, how does 'one' get further air out the system? I was going to bleed the doseur (as described in the hbol for early BXs) but I can't find a bleed nipple on my doseur.

I've ruled out the safety valve as it should self purge and besides, the suspension goes up and down quite happily (suspension being the first hydraulic element to be shut down in the event of pressure issues).

I know Jay's efforts with the lhm are fabulous as nothing but clean lhm is coming out of all the bleed points.

I still suspect air and will have a front wheels off the ground purging steering frenzy but have I missed anything? From memory Jay also cleaned the filters in the fdv and there is very little dirt (if any) in the system from what I've seen.

I have checked the tyre pressures and they are ok.

[JayW]

I believe steering bleeding is just lock-to-lock, ad nauseum...

I can confirm it was working when last used (and when we loaded her up) and LHM flush & replace was done in routine service along with the FDV strip & clean.

Has to just need a burp!

[rutter123]

isnt lack of pas usually associated with a weak hyd/pump? have you checked the accumulator sphere has pressure, as dosent this assist the pas and brakes to relieve pressure on the pump? please correct me if im wrong. my tzd has always felt a bit heavy on the pas but i prefer it as so.

[BX Bandit]

The accy sphere is a reservoir of pressure, there to support the pump in the event of high demand and/or a weak pump.
I've not actually checked the tick time, but it's fairly infrequent as otherwise I would of noticed, but I will check tomorrow. Further, I bought the car from Jay who (rather obscurely, for a bloke of his nature) knows (or at least seems to know ) what he's doing, and so I can fairly rely on his work done, I.e. Accy sphere ok, but it is worth a check (just in case the Morgan Spiced Rum had taken a hold on that particularly dark and windy night).

I've also no reason to suspect the pump. I've had a pump cover 200k miles without symptoms, yet this has done only 88k. The rest of the system is 100% excellent, so it would seem very steering only dependant.

[RobC]

I've always been led to believe that such is the demand on the system of the steering, that it relies on the pump much more than the acc sphere.

Easy way to know if the pump's worn is, at engine idle, how long it 'pssssh'es for before the 'click'.

'pshclick' = tip top; 'psssssshhhhhhhhhhshshshclick' = tired pump.

[BX Bandit]

Thanks Rob, I'll check that out today and do lock to lock steering ad nauseum. Sorry Rutter, It appears you could of been right about the pump idea!

[JayW]

Following on from Robs comment:

Low idle speed severely affects the pumps ability to keep the system fed and the tipping-point is a relatively small window!

With the athena idling very nicely at 800rpm the pump stays permanently locked in, at 850rpm it's a lengthy pssssssshhhhhhh-tic (as Rob so elequently put it), 900 and above it's back to normal with a 60 second interval.

Worth checking idle speed as you've played with the timing.

[BX Bandit]

Thanks mate, I spotted the same thing on Charlie's bx when it last ran, but it's not that.

The pssssssshhhhhhhhhh lasts between 2-4 seconds, so pretty good and the tick time is 75 seconds, very respectable.

I thought I cracked it, it seemed to get easier all of a sudden with the wheels off the ground but it still no good, maybe marginally better.

To top,it all I've come to the conclusion that my donor head is super fooked with about as much compression as something non compressed. Happy bunny I am not.

[Thread Bear]

Worn pump and poor steering. Yes I would believe this as my car exhibits the sound effects mentioned and the steering is still slow to come on line on starting up. I recall 1.7 Turbos needing pumps back in the day, I think the ABS has a bigger capacity pump limiting supply from dead cars.

On reactivating my car from 5 years slumber it took quite a while to get the steering to respond as it should. Now add in above and maybe there is a residual issue on my car. However I did what the guys said, Citrobatics and lock to lock and over an afternoon of mucking about and driving test trips steering performance returned to the point that I need to wait maybe an extra few seconds that I think is correct for steering. (In my case LHM leaks interrupted activity, hence afternoon). Lack of use would seem not good for BX.

[BX Bandit]

Thinking out loud here but glad of input in case I've thought wrong.

Presumably, I could crack the unions at the fdv (outlet to power steering), the pinion valve and the ram and see what part is getting oil under pressure. The grey area is if all parts are getting some oil, but not enough of it, but I guess that upstream of the problem, all else being well, the oil will spurt out, whereas downstream it will be more like a dribble.

Another theory to disprove a tired pump would be to turn the steering slowly? Tired pump would keep up with slow turning?

[MULLEY]

Try priming the pump? If there is air in the system the lhm will bubble whilst the pump starts to consume it.

[JayW]

I *believe* the steering works irrespective of whether you have full pressure elsewhere, which is why the steering should work even before the suspension lifts after you first fire 'em up.

The last port of call is obviously the pinion. So, as you say, crack the unions to the ram and see if you get a spurt and work back from there?

[BX Bandit]

Mulley, it's run long enough and done enough citerobics. As the suspension is the lowest priority I'd of expected suspension uppy problems if the problem was air in full system (if that makes sense)

Yeah makes sense Jay, odd one this, not had this before. Least of my woes mind, seems I'll have to do the head again

[BX Bandit]

A cursory (or is that cursive ?) glance yesterday revealed that, with no effort applied to the steering, oil is, as it should be, being circulated through the fdv and the pv. There is also increased flow when steering effort applied. This was seen by cracking open the unions on the pv.

So either there is an internal leak within the pv, an internal leak with I the ram or the fdv is not able to give enough pressure to assist, which I think would either be the fdv itself or the pump.

Being that the pssssssssddddd-tick thing is only a couple if seconds, and the certainly isn't slow on the citerobics front, I willing to rule out pump.

You can guarantee that if I replace a pv it'll be the fdv, or if I replace the fdv, it'll be the pv, or if I replace both, it'll be the pump!

Have I missed anything? Which is more likely? Any more tests to do?

Also, is there meant to be a hiss or some sort of pressure release on full lock? Cos there isn't one on this......

[Jaba]

Have you cleaned thoroughly the LHM supply filter in the tank yet ?