Power steering failure... Again...

Hi to you all.
Some help needed with diagnosing power steering issues.

It all started with a leaking pas pump. Ordered an overhaul kit, took the pump out, replaced the seals and gasket, built it back in and had a well functioning steering system for a short while.
Unfortunately the gasket blew (probably faced it the wrong way). I ordered a new pump, built it in, adjusted the steering box to get rid of the excessive slack and enjoyed at least another day of driving with a proper functioning steering system.
Not long after, I almost completely lost PAS. While driving it's fine of course, but low speed manoeuvring is almost impossible.
The new oil I put in looks black and polluted, not foamy however.
No sign of leaks.
I'm now thinking direction steering box, but would rather avoid replacing it if not necessary (LHD.

She's a 2003 td5 Defender.

Any help will be greatly appreciated.

I have to add that when I rev up (more pressure) the steering becomes a bit better. Could it by some miserable coincidence be the new pump?

Difficult to say, which probably explains the lack of responses you're getting. If you put the seals in wrong then it could be user error? Did you bleed it? It might be best have a mechanic check and/or install the pump and see if the problem still presents itself.

Hope you did not over tighten the steering box adjuster. Adjustment has to be done only with wheels/pump arm set straight ahead and allan key bolt only turned until contact just felt. Any slack with wheels turned to be ignored.

Everything felt fine after adjusting. Both wheels of the ground, free turning left and right with no hard points.
I know that too tight can lead to damage, but not likely to lose pressure? Or?

Popnagel said:

<snip>
The new oil I put in looks black and polluted, not foamy however.
No sign of leaks.

She's a 2003 td5 Defender.

Click to expand...

If the fluid is discouloured it does make you think that something rubber/plastic is breaking down. My fliud is still clear(ish) red after a few years.
I don't think there are any rubber/plastic items 'in' the pump although there are a couple of seals on the main shaft.
If the pump is new and not leaking that does kinda point towards the steering box (unfortunately) ...

Hoses delaminating inside?

In the pump it's only metal, just not seals and gasket. But then... It's a brand new one.
The pump to box hose is replaced with a new one too.
As I wrote, no foamy oil, so that should exclude air.
The oil could be mixed with old btw, since I didn't drain the box (if at all possible)

Hi, I know how you feel. I have had 2 steering pump failures on my Wolf 90. Both were OEM pumps. I fould the oil was discoloured by metal particles so that the oil looked like looking at the milky way. I flushed the pipes and steering gear with new Dexron 111 (2 litres by reverse flush, and replaced the pump and the reservoir as this has a filter under the baffle plate. About 700kms later I'm in the same place! I have stripped the steering box to find the worm bearings are through the hardening on the worm faces, but no way sufficient to kill the pump.

When flushing the steering oil get someone to hold the steering wheel hard on right hand lock. When steering right the assist valve opens to the entire steerong box to push the rack piston to the rear of the chamber. It wont change/flush all the oil but its better than nothing.

Check the steering oil with the engine running and look at the oil in the reservoir with a torch. If it sparkles, then you have metal particals in the oil and that aint good. Before you start up stick your finger in to PS oil reservoir and wipe the tip across the baffle plate on the bottom, if your finger comes away with a dark grey residue, thats metal filings. Yes, in both cases the steering assist slowly faded away to zero and given I have 265/75R16's fitted its bl..dy hard to steer!

I'm still not entirely sure what has caused these failures. The amount of filings in the oil point at cast steel which could be the pump housing, or equally the steering box assist piston bore. Hopefully I will know more tomorrow.

Cheers

Ian J