I just replaced my straight axle front end with a TCI mustang II setup with power rack and pinion steering. I am using a ford pump so high pressure is not an issue as found with GM pumps.
The problem seems to be intermittent. The steering will be working just like it should be then all of a sudden it will act as if there is no power steering. The pump is a remanufactured unit from a 1968 Mustang i just bought from NAPA auto parts.
I was wondering if anyone else has had this problem and what the solution is.

Thanks
Terry

 

I would try another pump.
Obviously first make sure the belt has enough wrap on the pump pulley, make sure the belt is not slipping during the turn of the steering wheel.
It's probably the pump.

 

It could also be air in the system. Turn slowly to full lock on both ends, don't hold long at either end. Let it rest a minute and repeat.