Power Steering Problem

Guru Meditation · Post by **Guru Meditation** » 18 May 2004, 00:50

Hello! How I love my ZX!......
The car (93 zx td aura@112k) has been unused for 2 weeks due to springing a major coolant leak, now fixed. (It was the water housing at the bottom of the block on the driver's side which had fractured somehow-bugger to change, no access to the pipes).
Now it has become apparent to me that it has developed a steering fault-it seems to have lost 90% of it's power assistance and now feels very odd. It will sit stably in a straight line, no probs, but when cornering the steering hardly self centres at all (I guess due to no assistance). I'm at a loss to see what's up-the PAS reservoir is full and it has never needed a drop of fluid since I've had it even now. Only thing I can hear is what sounds like an abnormal metallic tinkling type sound emanating from the engine bay audible when the engine is revving, but not really at idle. Previously when it was working it had the old sticking ram fault where winding off left lock at anything more than a slow pace would cause the ram to bind very strongly and this seems to be getting worse.
So it hasn't leaked so it must be an internal fault;
1) Steering rack - unlikely
2) Knackered PAS ram - likely
3) Knackered PAS pump - likely
I think the pump is knackered and the ram is knackered because it binds-but in this case it is the pump that is knackered causing loss of assistance. I guess if the pump was knackered a fault like binding in the ram would be more apparent.
Question is what do you think and how do I test the pump before I get another one?
Thanks
Guru Meditation

jeremy · Post by **jeremy** » 18 May 2004, 02:39

Have you replaced the ram yet?
http://www.andyspares.com/discussionfor ... x,steering
jeremy

Guru Meditation · Post by **Guru Meditation** » 18 May 2004, 04:54

No I haven't. Up until two weeks ago the steering was absolutely fine in terms of power assistance and feel etc apart from some binding when quickly winding left lock off, which I had put down to the ram. Now almost all power assistance has been lost despite their being no fluid leak and I am wondering what has caused it-the suddeness makes me suspect the pump although maybe the ram has given up the ghost-any ideas how to test?

AndersDK · Post by **AndersDK** » 18 May 2004, 05:09

Is the ram dry on the cylinder rod ? - even rusty ?

Post by **RichardW** » 18 May 2004, 16:49

>Only thing I can hear is what sounds like an abnormal metallic tinkling type sound >emanating from the engine bay audible when the engine is revving,
I reckon that is the internals of the pump going round where they shouldn't be. The other thought is that the suction hose has maybe collapsed and is starving the pump causing cavitation inside the pump. Perhaps you can run the pump with the outlet disconnected to see if it is actually pumping anything?

Guru Meditation · Post by **Guru Meditation** » 18 May 2004, 21:00

Hmmm I think I may end up doing just that to see if the pump is actually flowing. The idea about a collapsed hose is good though, never thought of that one. I am not 100% sure it is an abnormal noise but I am usually pretty good at picking out abnormal noises from my cars so I fear the pump may have had it.
Incidentally if the pump is working right what kind of flow rate can I expect to see from the high pressure outlet? Presumably more when the steering is being wrenched?

Post by **philhoward** » 19 May 2004, 01:00

Silly suggestion...contamination/looseness of the PAS belt? At idle, get someone to (try) and turn the steering wheel. You MAY be able to see the belt slip. It may not necessarily squeal; depends on the slippage factor.

Dave Burns · Post by **Dave Burns** » 19 May 2004, 03:42

Looking at the volume of oil delivered by the pump wont tell you much except that it is working, the output pressure coupled with the volume is whats important.
Pump output is constant and only changes with engine speed, whatever the demand from the steering may be, even if there is no demand for power assistance at all.

You know the ram is goosed so change that first, simple enough to test, take it off and drain it by extending and contracting it, then block both ports off with your fingers and pull and push the piston rod in and out, if its no good it wont develope much pressure or vacuum at either of ports because the air is going past the piston seal.
A good ram will force tha air out past your fingers on one port and suck vigourously at the other port at the same time.
Dave