TM 10-3930-671-24 Main Hydraulic System System Components • Sump tank  • Main pump • Priority demand valve * Main control valve • Associated lines & hoses • Full flow, return line oil filter • Oil from sump tank is fed by gear pump through priority-demand (flow control) valve to main control valve.  At priority- demand valve, required flow is diverted to steering system.  Oil not used for steering is added to lift of tilt system.  Main control valve directs oil to either lift or tilt cylinders.  Oil returns to sump through filter. • Hydraulic sump is separate, removable tank in RH side compartment of frame.  Has large top opening with removable cover  including  full  tube/breather,  oil  level  dipstick,  and  oil  filter  return  line.    Cover  held  on  with  V-band  clamp.    Sump breather is standard Clark part. • Main hydraulic control valve has adjustable system relief valves, and counterbalance valve in tilt circuit with pressure- compensated flow control valve to control tilt speeds.  All ports and connecting lines on bottom surface of valve. • Optional single or double aux sections may be added to outer side of standard (lift/tilt only) main valve. Aux sections have adjustable relief valve w/optional flow controls for:  2.5, 4.0, 5.5, 7.0, or 10.0 gpm flow. • Hydraulic system relief pressure is "tuned" (adjusted) to match the truck rated capacity. Maximum pressure 3000 psi (nominal). • Main hydraulic valve has diagnostic quick disconnect fitting for checking main hydraulic and steer system pressure. Main Hydraulic Pump mounted to drive pad on transmission · Pump RPM: 1.03 x engine rpm · Pump Flow: 13.1 gpm (49.6 L/min) @ 1800 rpm (pump) & 500 psi 11.7 gpm (44.3 L/min) @ 1800 rpm (pump) & 3000 psi Note Maximum design pressure is 3000 psi (20,700 kPa). Hydraulic System Main Relief Valve GPX 25E: 2600-2700 psi (17926-18616 kPa) Pressure Settings: (Lift & Tilt) Aux Valve Relief Pressure Settings • Adjustable up to 19252075 psi (13270-14307 kPa) * (Refer to attachment specifications) Recommended Hydraulic Fluid: Clark Spec MS-68 Hydraulic Oil with anti-wear additives. F-23