The charge relief valve (Item 1) [Figure 30-51-18] is located on the back of the hydrostatic pump.
Remove the charge relief valve.
Assembly: Tighten charge relief valve to 52 ft.-lb. (70 N•m) torque.
Check and replace the O-ring (Item 1) [Figure 30-51-19].
Inspect the poppet (Item 1) and the mating seat (Item 2) [Figure 30-51-20] for damage or foreign material. Ensure the poppet moves freely in it’s bore.
Inspect the sealing ring (Item 3) [Figure 30-51-20] and the mating seat in the pump housing for damage or foreign material.
Inspect the spring (Item 4) and the charge relief valve shims (Item 5) [Figure 30-51-20].
NOTE: 1.0 mm shim (Item 5) [Figure 30-51-20] = 43.5 PSI (3 bar) in pressure change. Adding shims increases charge pressure. Removing shims decreases charge pressure.
