Tight steering

[AdsLandies]

The steering on my County has all of a sudden become feeling tight, almost binding-up when turning. Something similar happened recently, and I changed the tie-rod ends and it seemed to be Ok after that. However, it just started doing it again the other day. Have removed the steering damper to see if this could be the cause of it, but it's not. With the front of the vehicle jacked up off the ground the steering turns freely from lock to lock with no binding up at all. Power steering fluid level is good, and no leaks anywhere. The steering box seems pretty good with very minimal slop in it. I'm a bit sus that it has something to do with the Isuzus power steering pump but haven't really heard of many issues with this before. Any ideas guys?
Thanks,
Adam.

[steveG]

Isuzu PAS pumps are just a vane pump with a pressure relief/regulator valve. Not much to go wrong. I had an issue with mine where some crap inside the pump had jammed the relief valve open so the steering would go hard intermittently. Eventually it got stuck in the valve and the steering was hard all the time so I pulled it apart and found the issue. The crap in mine was from it sitting open on the shelf at the wreckers for ages. I rebuilt it before using it but there was still something inside which dislodged when it was operating.
Unlikely to be the issue with yours unless you've had the system open.

Something else to to check are the steering shaft universals as these can bind up.
Maybe redo the lock to lock test you did with just a bit of weight on the wheels as it could be a case of a little load causes it to bind up harder.

Also check for anything physically rubbing on the steering components - especially with weight on the suspension. IIRC someone had a snorkel hose catching on the steering shaft recently.

Steve

[flagg]

IIRC someone had a snorkel hose catching on the steering shaft recently.

Steve

I've had a few things catch on the shaft - snorkel hose (now has a hole in it from rubbing) but the one that scared me was a Brass T in my maxi-drive vacuum lines got caught in one of the joints.

[AdsLandies]

Thanks guys. Unfortunately the steering knuckles don't seem to be the problem either so need to keep looking. Don't know if I'm dreaming this, but if I do a bunch of lock to locks before I drive off it seems a bit better. Hope to sort it out soon as it's pretty annoying to drive at the moment (well, if you need to turn that is). Think I'd better check that relief valve you mentioned Steve...

[AdsLandies]

Just an update on this, turns out it was one of the steering knuckles. With the steering shaft removed the knuckles moved freely initially, but one did bind up while wobbling it around. There was obviously something floating around in there which would free itself sometimes. After soaking it in diesel for two days and rotating it through all its positions for ages it no longer jams up.
I periodically spray these joints and oil them, so didn't expect it to be the problem. I've now found out that you can really only oil these properly with the shaft removed. There is a drilled hole which gives access to the cross pins where the oil can be worked into the knuckle. Steering is super light now.