The Mann-Filter HD722 hydraulic drive oil filter is a replacement element for the tractor hydraulic system. It removes particulate contamination from the oil circulating through the drive circuit. The filter sits in the return line, trapping wear debris before the oil re-enters the high-pressure pump and downstream control valves. A clogged filter element forces the bypass valve open, allowing unfiltered oil to circulate and accelerate wear on pump components. The manufacturer's design matches the housing's seal groove and bypass-valve cracking pressure, so the filter seats correctly and the bypass opens only when the element is fully loaded. On installation, replace the housing seal and torque the cap to specification.