I changed the PS fluid in my D2 and added Lucas like Disco Mike reccommends about 6 months ago and noticed ever since my fluid replacement I sometimes loose my power steering while turning at high speeds. (ie. exit ramps on expressway) This can be scarry / unsafe. It does not happen all of the time and does not make and noises...... The steering just gets very stiff and them seems to go back to normal once I begin to move in a straight forward direction.

Fluid Levels are correct and I don't see any leaks.....Does this sound like a PS pump issue or Steering rack issue. Truck has 190 K miles.
Any help would be appreciated.

 

I know little to nothing about how power steering works but I'm going to toss out my first thought on the subject. Sounds to me like you may have an air pocket in the steering gear box. That's all my uneducated brain can think that would cause something like that. And I have no idea on how you would go about getting the air out of the system. Maybe turn the wheels back and forth with the cap off the reservoir?

 

Actually I tried that shortly after I changed the PS Fluid. I used a turkey baster to change the fluid and then added the new fluid. Once full I turned the wheel lock to lock several times with the front end off the ground to ensure and air would be purged out.

Anyone else have any other suggestions?

 

You dont have a rack and pinion, you have a steering box with a Pitman arm, so other than the pump or the steering box there is nothing else that can go wrong.
If I didnt have a problem to start with I would not have used the Lucas.
There is a bleed screw ontop of the steering box, start the truck, loosen the screw and have a friend turn the steering wheel from lock to lock.
If I remember right the bleed screw is a allen head.

 

Go buy 2 more quarts of p/s fluid and suck out and replace some of the old fluid. Sounds like the pump may be failing.
As far as using the Lucas, if you are having a problem with it, this will be a first for me to hear about.
Change out some of the fluid, see if anything changes and get back to us.
By the way, have you checked your belt, is it slipping, loose or in need of replacement?

 

i have a 97 disco. It says that it needs an atf fluid instead of a power steering fluid. So does it mean the ATF fluid for the transmission?

 

Yes, DI's use Dexron III in the power steering system.
If you have a leak then buy ATF with stop leak in it and top off with that until the leak stops.
Do NOT use more than half a quart of the ATF with stop leak as it will clog your system.
If the leak wont stop then you will need to fix it.

 

I kinda added a little bit of a power steering fluid. Do I have to flush my system just to take it out. Or is it ok just to leave it?

 

Well I lived with the issues and finally need to replace the pump and / or steering box. I am not sure which one. I have a noisy pump (the sounds is a groaning / whining like the fluid is low, but it actually full). And the truck started leaking PS fluid tonight. There is fluid leaking all over the frame rail and inner fender, hoses. How do I know if the steering box is shot or if the pump is shot?

 

fill it up and add dye and check for leaks. Seen a few pumps go but seen a box that broke internally causing a loss of power steering with no noise just no power steering.