Charge pressure relief valve
The charge pressure relief valve is shim adjustable (early models) or screw adjustable (late models). Screw
adjustable charge relief valve is shown.
Removal
1. Remove the shim adjustable charge relief valve plug with a 1 inch hex wrench.
Before removing the screw adjustable relief valve plug, mark the plug (K90), lock nut (K10), and
housing to approximately maintain the original adjustment when assembling. Remove the screw
adjustable charge relief valve plug by loosening the lock nut with a hex wrench corresponding to the
table.
Lock nut wrench size
Frame size Wrench size
030 – 100 1-1/16 inch
130 – 250 1-5/8 inch
Unscrew the plug using a large screwdriver or 1/2 inch hex wrench. Remove and discard the O-ring
(K50).
2. Remove the spring (K70) and relief valve poppet (K80).
Inspection
Inspect the poppet (K80) and mating seat in the endcap for damage or foreign material.
When inspecting shim adjustable valves, do not alter the shims or interchange parts.
Service Manual
Series 90 Pumps
Minor repair
48 520L0818 • Rev 0101 • August 2015