part time problem

my 72 new yorker has had a part time problem . the steering wil cautch/lock up when im turning left . we thought it was cause the pump was leaking & then we found out it had the wrong pump to we changed that . everything seemed fine till i was out d\for a short drive & as i was turning left (about a 1/4-1/2 revolution of the wheel it almost made me have a accident . so i got her home & parked her . we tried to make it do it in the driveway & it wouldn't till i had it...

part time problem