Have a 71 Chevelle with a 99 ls1 and a steering box from a Jeep Grand Cherokee. Power steering does not work most of the time, on occasion it will work somewhat. The box is rebuilt and I have put two different pumps on it with the same results. Thoughts? Is there a pressure difference between boxes and racks? Since these pumps are from cars with racks and is now on a box.????

 

Belt slipping ?

 

My LS3 Corvette pumps works great with my AGR steering box. My guess is you have air in the system.

Andrew

 

I've had zero issues with my jeep box. I'm running the corvette pump with holley brackets.