After replacing three rebuilt power steering pumps (from Advanced Auto) I am still having leakage and pump failure. I've replaced the power steer pressure hose, the "O" rings and the non-pressure hose. Could a bad steering box contribute to the failures? This is beginning to drive me insaine.

 

after the second rebuilt failed i would have demanded a new one

never use rebuilt parts on something like this, i will always buy new. the box should not have an effect on pump failure, and pumps are relatively tough units (mine ran dry for 30+ miles when my hoses rusted through and the pump is still fine)

 

Yes a gear box can be plugged and cause your failure, however I would replace the pressure sending switch as well. It should be inline on the pressure line.

It is always a good idea to replace both the steering box and pump when one goes out because metal flake can do a number on the internals. Also there are 2 types of power steering fluid in the years of the box/pump combo, if you use the wrong fluid it will cause failure. You might need the Brown fluid only available at your dealer, or it could be ATF+4 transmission fluid, but most likely it is the Brown fluid. Brown fluid is like $7-$8 dollars a quart.