1967 GTO Power Steering issue
Hi guys, I am having an issue with my power steering. First off, I have replaced the pump and box with replacements from Ames and the system was purged of air etc. The pump was leaking and the pressure valve? In the box went bad causing too much pressure in the pump shooting the cap out of the reservoir. The engine is a 461 and all is fine now. The issue I am having now is after i drive for 20-30 minutes if i make a sharp right or left hand turn into a driveway or at a stop sign or parking spot, I have no power steering. It feels very stiff and i have to fight the wheel. Once I'm parked, or straighten out the steering returns to normal. I am using gm type power steering fluid and there is no leaks,bubbles or whines coming from the box or pump. Any insight would be appreciated.