PS Gets Harder as Car Gets Hotter

[Ken in MN]

Hi,
After replacing the ps pump and and steering gear box, I noticed that the steering is easy when the car (and pump) is cold but gets increasingly more difficult as I drive. It's almost as if I have very little PS pressure when the pump is hot. It's almost impossible to parallel park - it's that stiff.

Also, when this happens, the pump gets too hot to touch. How hot should it get?

I'm using PS fluid in the system. Would it make a difference if I switched to ATF? If so, which brand of ATF should I use?

Suggestions?
Ken in MN

 

[BillinAl]

Use "Type F" automatic transmision fluid in the power steering system. Doing so will probably cure the problem.

 

[Ken in MN]

BillinAL,
I syphoned out the old PS fluid (three times) and replaced it with Type FA AT fluid. I hasn't made an appreciable difference in the steering. In as little as 15 min of city driving, I can tell that the effort to move the wheel is getting harder. The pump still gets very hot (too hot?) - way too hot to touch. I need to use a rag to remove the cap when checking the fluid level. Any other ideas?

Does anyone have any input about how hot their pump gets when driving?

Ken in MN

 

[tbird5866]

You may need new hoses. Could be a flow restriction somewhere. It might very well get more restricted as you use it.