How to test power steering?

[Boothy]

Following losing power steering on my last event out, I decided to change my steering box for what looks like a recently reserviced 4 bolt "like for like" one of a classic RR I broke last year.

All the pipe work is good and the pump is a ZF74 one which was brand new a few months ago.

The steering without the engine running on axle stands feels fantastic, really smooth and direct with virtually no play, "cracked it" or so I thought.

Started the engine up to bleed through and the steering doesn't feel like its any better or being assisted, worked it loads of times left to right to remove the air, and time to let it down on the floor.

Its cr*p and is hardly able to move at all, as soon as any effort is applied (which is a lot) to try and change direction (whilst stationary) is made all I get is that horrible noise that usually occurs when you reach the end of normal travel.

What I did do (bad mistake and laugh if you've done it) is to undo the bleed nipple on the box with the engine running and try to steer, the fluid hit the garage roof and virtually everything under the bonnet, which makes me think the pumps pumping to some degree.

Any idea's boys, qualified ones if possible please, common sense tells me its the pump, but its another £175 guess to replace it, I've hopefully got another steering box comming today to try, but the one I saved and changed in the first place was a good one. The original box was a recon from Paddocks last year. All the pipes are clear and not kinked etc, and yes its new fluid.

Thanks lads

[GBMUD]

Loose belt by the sound of it. That is the sound one often associates with reaching the lock stops. I would certainly check that first, they transmit a lot of power and so need to be good and tight - much tighter than an alternator belt.

The other noise one can get at full lock is a pressure relief valve opening in the system - in the pump at a a guess.

Chris

[Boothy]

Its certainly not a loose belt, it's a deeper problem than that,

I'm also aware that the noise is the pressure releif valve but why would the relief valve be letting of pressure when the steering box is basically in mid position?, especially when as it says in my post the steering is actually very light when on stands and certainly lighter than the the original box I replaced, incidently when I was fitting the box when I turned the steering the box was spitting a bit of fluid out of the pipe holes, so I presume its not blocked or anything daft like that.

[FridgeFreezer]

Could be a stuck PRV, or faulty PRV if it's blowing off as soon as you load it.

[MJIbex]

Not much help to your problem, but the price of 4 Bolt boxes from Land Rover has been reduced very recently to £220.

Mark.

[steve_d]

Is it possible to put the pipes on the wrong way round?

Steve