1988 xjs v12 hard to steer, up on jacks front wheels turn easily from stop to stop. Flushed power steering fluid, with the cap off i noticed forcefull circulation of the fluid coming back into the power steering pump. figured that its not a pump issue. No leaks to be found. Put the wheels back on the ground (lowered jacks) cant hardly turn wheel at all. above 10 mph turning is ok. slower gets harder. puzzeled????????????

 

Steering gets easier as the car increases speed, that's normal.
My guess is either a weak pump or the rack has a stuck valve or is shot. I'm sure others will chime in though!

 

You need to check the pressure on the high pressure line,it should be 1100 to 1200psi. If this is low even 800psi there will be almost no assistance.

 

Failed internal seals on the rack = no assist. It will turn easily off the ground but will be very hard at rest.

The rack is rebuild-able, but is not normally a DIY job.

 

vapor locked possibly.

 

Damn, i did not want to hear this one.

 

O.K Here it is, figured id take the p/s pump off first (easiest) opened it up and to my surprise the clip ring that holds the end cap in place had come 1/2 way out of its crevice. also was evidence of pieces of rubber seal. Ordered another p/s pump with pulley. hope to have it on by the weekend. More will be revealed!!!

 

cool...might want to flush the system though