I've owned my 1996 XJS for about 8 months and 5,000 miles.
On three isolated occasions I experienced a total power
steering failure when pulling into a parking spot.

As I accelerate and turn the wheel all the way to make a
90 degree turn, somewhere midway the turning of the
steering wheel, I lose power steering. I usually flip the
tranny into reverse and turn the wheel the other way,
backup a bit and then complete the maneuver. As soon as I
turn the wheel the other way, power steering is restored.

Power steering fluid is not low.

No visible evidence of leaks.

I can't recall if it has always happened when turning the
wheel in the same direction.

What do you think is going on.

 

Has the power steering fluid ever been changed? If not, I'd do that first and see if the problem goes away.

Cheers,

Allan

 

If the 1996 has the saginaw pump same as the earlier models, there is a pressure valve (in the pump) that regulates pressure to the rack these valves can stick causing a loss of fluid pressure.

 

OK, that doesn't sound like it's anything to worry about then...at least until it happens more often, in which case a new pump will be required.

Thanks for filling me in!

 

The last of the V12s used the old Saginaw pump, yes. The 4.0 six cylinder cars used a shaft driven pump....but even those had a similar-looking control valve arrangement.

I've never delved into the later type....never had reason to....yet. However, a sticking valve does sound plausible. Perhaps a teardown for cleaning and inspection would reveal something?

Or, as mentioned, a complete fluid change might be enough to unstick things? That's an easier first step.

Cheers
DD

 

Hey Vee, what ended up happening with this? I'm having similar symptoms with my 1995 4.0 coupe.

Thanks!

 

Car was rear ended and totaled.

The replacement car hasn’t done this at all. Sorry for the lack of help.

 

Look under the wheel wells for scuffing or tire sidewall ware.