Ghibli power steering

Hi, I'm looking for some help on how to a diagnose power steering problem.

1968 Ghibli (number 652) - outfitted with all original factory parts to add power steering sometime in the 80s I believe. I've owned the car 17 years and power steering has always worked really well - suddenly it's gone bad.

Symptoms:
- Steering wheel feels stiff throughout travel.
- steering feels "wandery" - but probably due to stiffness at center making quick corrections impossible.
- Doesn't feel lighter as car speeds up - would expect steering effort to drop above parking speeds, but feels sort of "constant resistance"
- happened while car was parked - i.e. parked it and it was fine - but drove it a month later and it was faulty

So far...
- the reservoir is full of fluid and it looks new (isn't)
- no squealing or other loud noises when turning the wheel (car parked, engine running)
- turning wheel lock-lock and back a few times - no noticeable difference or improvement.
- no drips or fluid leaks visible - but haven't yet taken anything off to look closer

I'm really looking for a plan of attack - how would you go about this? What's your first guess at the problem? How do I eliminate some possibilities? I can do most things but this is the only car I have with power steering and it's always worked - therefore a bit clueless on where to begin.

Thanks for any/all help,

-Richard

 

Thanks a lot Dan, I will try to call you today.

Anybody else have suggestions or encountered anything like this?

Thanks,

-Richard

 

No, not yet. Other projects have some first, unfortunately. I did speak to Dan who was extremely helpful (thanks Dan!).

He suggested removing the reservoir's lid while the engine is running and look for turbulence in the fluid - if there's none then it's likely a pump problem. If so, it's not clear whether these pumps can be rebuilt, but there are ways to use similar pumps which is what he does - anyway, I'll cross that bridge when I come to it.

Also to check under the pressure-release valve cover and check for whether the spring under there is working as it should - I'm not sure yet how that works, but I will do that too.

I told him I was going to replace all the steering ball-joints while I was in there - and he warned me about the latest replacement ball-joints all being very stiff when new - so stiff that the steering won't self-center. He has had success with spinning the joint with an electric drill for 30-60 seconds and then they free up enough for real use. That doesn't sound great, but I'm willing to try it. The new ones are definitely pretty stiff.

 

Hi Bart,

Thanks for that suggestion - yes it did happen after the car hadn't moved for about 5-6 weeks.

I guess I'm suffering from not properly understanding how power-steering systems work - I will do some studying before I undo a single nut. But I had been thinking that I need to get the front up in the air and see how it feels with and without the motor running - then I'll disconnect the hose as you suggest and feel the difference. Not sure when I'll get to this, but soon.

Thanks again,

-Richard

 

Hi Bart,

Thanks for the clarification - you were clear, I just didn't read closely enough - the shaft that you're suggesting may be "sticky" is the steering-wheel shaft from the wheel to the box - First time reading I thought you meant the shaft coming out of the bottom of the steering box and into the linkage.

Thanks I'll try to do that tomorrow.

-Richard

 

To follow up on this...
Following advice from Dan I went through a few diagnostic steps
- There was very little sign of turbulence in the PS fluid reservoir
- but there was some sign of "assistance" from the PS system (hearing hissing from the steering box and note changing at full lock


Decided to flush, bleed and refill the system. My system has a remote reservoir so had to work out a way to plumb in my power-bleeder, but got it done and blew out all the old fluid (at least 18 years old...I know...)

No sign of blockage in the base of the reservoir where the filter is, so re-filled with Valvoline ATF. Made a mistake and inserted an air-bubble, bled it again, etc etc.

Then, very stupidly, I looked at the top of the ZF steering box and decided it looked just like the ones in my Alfas - therefore removed it with a view to sucking out the old lube and re-filling. Alas, they are not remotely the same, and I was rewarded with the sight/sound of needle-roller bearing falling down into the box as I lifted the lid off. The air turned blue. But, I managed to get t all back together - but see below.

Then, re-started and definitely more sign of PS system now working better - but driving the car down to Monterey for CI and various other events, it was horrible. Stiff in the middle, PS seemed to stop working mid-drive, very "wandery" and difficult to keep straight (still a great weekend though)

Decided this was due to the new stiff ball-joints I did at the same time. Jacked it up and stripped the steering joints - some of them are extremely stiff - spent some time working the joints to free them up. Also discovered that freeing the adjustment nut in the middle of the steering box lid made a big difference to the feel of the wheel in the center - so obviously during my disastrous box-disassembly above, I'd ruined the adjustment, too tight, and now it needed slackening.

I haven't tested the actual pressure out of the PS pump which is probably what I should do, but I don't know how. It doesn't leak and its pulley is turning.

Now I have all the brakes in pieces too, so I cannot report on the final product, but I believe I'm on track - thanks to all who helped.

-Richard