Power Steering Failure

Hi Everyone,

1996 Discovery 300tdi auto. Working fine 'til this morning. Reversed into parking space and steering wheel went stiff when trying to straighten wheels. Left it while at work - quick check - fluid level okay - no obvious leaks - drive belt okay - nothing else I can see without a proper look.

Any thoughts as to where to start my investigations?

Thanks Davy M.

Reply to
David Murray
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Sticky relief valve on the pump?

Reply to
EMB

On or around Wed, 28 Jan 2009 07:29:00 +1300, EMB enlightened us thusly:

yeah, something like that would be my guess. you've covered the obvious, now it's down to internal things - so pump or box. something's stopping the fluid. For it to happen suddenly, it must be some kind of failure rather than say a blocked filter, which would be slower to have effect.

does it make any untoward pump noise? I've an idea the pump pulley is keyed to the shaft, so possibly the pulley is turning and the pump isn't?

Reply to
Austin Shackles

Check the boss on the steering pump shaft is close to the pump housing (1mm or so) - probably can see ok just by looking at the pully alignment. Common fault is the pump bearings collapse and the shaft/key flogs out - shaft will then move out of the pump. Sometimes it will continue pumping ok under duress (translate this to leaking and noisy). Other times it becomes a near failure and you will end up with arms like Popeye trying to steer the car.

--Craig.

Reply to
Craig

Just checked again in the daylight. The Pulley and shaft have slid forward out of the pump. I guess that what you have described has happened. Got no noises though - just stopped. Looks like I'll be fitting a replacement pump.

Thanks for the info guys.

Davy M.

Reply to
David Murray

Someone's already diagnosed the pump, but I should also mention the pipework and clips wear through also - may be a thought to replace these pipes at the same time if you budget allows.

Reply to
Alex Threlfall

On or around Wed, 28 Jan 2009 22:51:02 GMT, Alex Threlfall enlightened us thusly:

what d'yer make of one that's noisy and apprently works fine?

Reply to
Austin Shackles

Noisy how so Austin?

It's not low on oil and sucking small quantities of air is it?

First up I'd try changing the oil, and see if that settles it down. Best way I've found to do that is to take the return pipe of the reservoir and put it into an empty container, then run the engine whilst topping up the reservoir until clean oil arrives from the return pipe.

It may be a non-genuine hydraulic hose fitted to the vehicle - I did an emergency repair to a Nissan a few years back with ordinary hydraulic hose and the bloody thing moaned like a haunted outhouse. Disassembly of the failed hose showed a restrictor in on of the fittings that massively reduced the oil flow (and noise).

It may be the relief valve chattering - disassembling said valve and giving the shuttle a polish with some 1200 grit sandpaper might sort that out.

Reply to
EMB

Thanks everyone. New pump fitted and steering now wonderfully easy to turn - compared with the drive home without power assistance! The pump spindle had slipped out of the bearing and allowed the pulley to move forwards and out of drive.

Happy motoring.

Davy M.

Reply to
David Murray

On or around Sun, 01 Feb 2009 09:30:54 +1300, EMB enlightened us thusly:

nope. sounds like one with air in it, but no air to be seen, no obvious leaks, fluid level up, tried bleeding it, etc. Works fine, no notchy steering or feeble assistance.

Might try an oil change, I had thought about that. I'll keep the other stuff in mind.

Reply to
Austin Shackles

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