A walk behind aerator (100) hydrostatic traction drive system includes left and right rear wheel hydrostatic motors (202, 203) driving left and right rear wheels (104) positioned forwardly of a coring head (114), and a front wheel hydrostatic motor (204) driving a single steerable front wheel (102) carried in a pivotal yoke. The pivotal yoke is coupled to a handle assembly (110) attached to a neck extending upwardly and forwardly for pivoting the single steerable front wheel (102) about a vertical pivot axis. A check valve (207) is connected in parallel to the front wheel hydrostatic motor (204). The check valve (207) opens if the walk behind aerator (100) moves in a forward direction and the handle assembly (110) is turned to pivot the single steerable front wheel (102) and the front wheel (102) rotates more than each rear wheel (104), or if the walk behind aerator (100) moves in a reverse direction.
