4-82. HYDRAULIC PUMP REPAIR (M840) (Con?).
Hydraulic fluid pressure is extremely high when adjusting hydraulic pump. All safety
precautions should be taken when performing operation. Wear protective clothing,
hand, and eye protection. Failure to follow this warning may result in injury or death.
Adjustment procedures may be performed with hydraulic pump and pressure gage on a
Connect hydraulic pump to hydraulic pressure gage capable of pressure to 6500 psi (44,818kPa).
Fill hydraulic pump with hydraulic fluid and bleed air from system (para 4-75).
Ensure that lever (31) Is facing PUMP position.
Remove Six bolts (2), cover (15), and gasket (18).
lighten valve adjusting plug (17) to fully close
relief valve (20).
Install gasket (16) and cover (15) with six bolts (2).
Operate hydraulic pump until pressure gage
reads 6000 psi (41,370 kPa).
Remove six bolts (2), cover (15), and gasket (16).
Slowly rotate valve adjusting plug (17) counter-
Clockwise until gage pressure starts to dropt then
rotate plug ¼ turn clockwise.
Again install gasket (16) and cover (15) with six
With lever (31) still facing PUMP position, operate
hydraulic pump. Pressure should remain between
5800-6200 psi (39,99142,749 kPa).
12. If necessary, repeat steps 8 through 11. Rotate
valve adjusting plug (17) clockwise or counter-
clockwise until proper pressure is maintained.
Rotate lever (31) to RELEASE position to release
Remove hydraulic pressure gage.
l Install hydraulic pump (pare 4-81).