HydraMaster Boxxer 423s - Figure 5-1. Remove Valve Cap and Valve Assembly; Figure 5-2. Inspect Manifold and Old Valves; Figure 5-3. Replace Center Inlet Check Valve with Modified Check Valve; Figure 5-4. Apply Grease and Install Valves

5-9: Machine Maintenance Machine Maintenance: 5-8
Servicing Valves on the High Pressure Pump
Removing a Valve
1. Remove the valve cap (30 mm) and extract the valve assembly (see Figure 5-1).
2. Remove the valve assembly (retainer, spring, valve plate, valve seat) from the valve
cavity.
3. Remove the O-ring and support from the valve cavity.
4. Examine the O-ring and replace if there is any evidence of cuts, abrasion, or
distortion.
5. Inspect the manifold for wear or damage (see Figure 5-2).
6. Inspect the old valves for wear or damage. Only one valve kit (P/N 000-078-521)
is necessary to repair all the valves in the pump. (The kit includes new supports,
O-rings, valve seat, valve poppet, spring and retainer; all are pre-assembled.)
Figure 5-1. Remove Valve Cap and Valve Assembly
Figure 5-2. Inspect Manifold and Old Valves
7. Replace the center inlet check valve with a modied check valve
- Figure 5-3.
8. Apply O-ring grease to O-rings and install valves (Figure 5-4).
9. Replace valve cap and torque to 95 ft lbs see Figure 5-5).
Figure 5-4. Apply Grease
and Install Valves
Figure 5-5. Replace Valve Cap
and Torque to 95 ft lbs
Figure 5-3. Replace Center Inlet Check Valve With Modied Check Valve
Modied Check Valve