when my power steering fluid is cold while driving 45+ mph. my steering shakes violently. its only when i am manking bends in the road, because it deoesnt shake when i am going straight. i know it has to do with my pump or something because i just put in a hydroboost and it NEVER shook at all before. i am also running a stock PS pump with one inlet. my truck is a 1967 with a 454 (not stock). whats wrong with this thing? after the fluid gets warm its doenst do it anymore either.