Power Steering Failure; Aarrgh!

[nutshell]

Hi all

My 91 SVX has decided to lose its power steering, and alerted my by lighting up the STEERING warning on the dash info panel.

It is NOT losing fluid and all appears OK in the engine bay.

Is this symptomatic of the dreaded O-ring failure between the reservoir and the steering pump - or something more sinister?

The steering still works, but with no assistance.

Any pointers to analyse the fault, and remedy it, are more than welcome.

[Crazy_pilot]

Check the power steering fuse. Jay had something like that happen at Reading, full fluid and the pump turning fine, but no power assist. Turned out to be the fuse or a loose wire or something.

[nutshell]

Thanks. Where is the fuse located; main block location?

[Crazy_pilot]

yup, under the hood I think.

[nutshell]

OK... an update.

Yesterday I took the beast into my local service center, where they held it for 24 hours, presumably to apply the kiss of life.

However, the news was all bad.

"Looks like you're going to need a new steering pump", said the service manager. "We've run the tests, checked for fault codes on the select monitor and manually attempted to erase the codes stored in the system. We replaced a blown fuse and then re-ran the tests and checked the resistance sensor on the pump. We found excessive resistance on the pump, indicating a lack of flow from the pump. I am sorry, but in our professional opinion the pump is faulty and requires replacing".

To be honest, I thought he just may have had a valid point there.

About 1000 kilometers ago the low pressure return line on the steering split just as I entered a car park. All the steering fluid drained away to ground and the beast had to be towed in and the line had to be replaced. I guess there was always a possibility it could have cut a seal or damaged a bearing in the 15 seconds it ran 'dry' before I killed the engine.

But a new pump? Our local cost for a new pump (ex Japan) is $1000+. Including taxes, of course.

A new pump. Sheesh!
A thousand buck bucks - Double sheesh!!

HOWEVER, just as I was starting to get used to heavy no-power steering, guess what?

About four hours after retrieving the beast from the technical medics, I had parked in town to do some biz, climbed in, started it up and...the light went out and the power steering came back again!

With my luck it likely won't last, but obviously the pump is not the problem.

My thoughts are that the fault is somehow electrical and linked into the speed sensitive steering module, or something (like a teeny bit of crud) blocking a valve (very unlikely I agree), or...or...??

So...has anyone got an idea of what's going on?
Before I gently, but with malice aforethought, suggest to the technicians where they can stuff their professional opinion.

And, more importantly, so that the next time it happens to me, or to anyone else, we can maybe "unwind" the event and get it back again.

Oh, and if anyone has a spare power steering pump, Part # 34411 PA071 – PUMP ASSY CO9, please let me know. Just in case.

update:
It's a week later, and the PS is behaving itself. Very wierd !
Checked in with a tech friend who claims he can excise the PS module if (and when) it finally kicks the bucket and replace it with something that will "do the job". My thoughts right now is a failing capacitor (or somesuch beast) in the Variable Speed module. I had a similar sort of intermittent fault in a Toyota SC400 (Soarer) I owned a year or 3 back. It manifested itself by blinking out the entire dash. Very confusing. We found 2 capacitors had failed (as in leaked) and taken pieces of the circuitry with them.
Methinks we'll have to wait for this to die properly before we stand a Snowball's chance of fixing it.