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| Illustration 1 | g01113786 |
The Multi Terrain Loader hydraulic schematic (1) Pilot Valve (hydrostatic system) (2) Pilot Valve (work tool) (3) Diverter Valve (automatic level control valve RAISE) (4) Lift Cylinder (Left side) (5) Lift Cylinder (Right side) (6) Tilt Cylinder Group (Left side) (7) Tilt Cylinder Group (Right side) (8) Quick disconnects for the "A2" auxiliary circuit (9) Quick disconnects for the "A1" auxiliary circuit (10) Coupler Cylinder Group (11) Control Valve (work tool) (12) Solenoid Valve and Mounting Group (quick coupler) (13) Pressure Switch (optional backward travel alarm) (14) Accumulator (15) Return Manifold Gp (16) Hydraulic oil filter (17) Gear Motor (fan drive) (18) Hydraulic oil cooler (19) Piston Motor Group (hydrostatic left side) (20) Solenoid Valve and Mounting Group (21) Piston Motor Group (hydrostatic right side) (22) Gear Motor (air conditioner) (23) Piston Pump (hydrostatic system) (24) Gear Pump (25) Hydraulic Tank Gp | |
The Multi Terrain Loader hydraulic system consists of a hydrostatic drive system, a work tool hydraulic system and a pilot hydraulic system. The hydrostatic drive system and the work tool hydraulic system are controlled by the pilot system.
The three systems use one common hydraulic tank (25). The gear pump (24) is attached to the front end of the Piston Pumps (hydrostatic system) (23). The Piston Pump (hydrostatic system) and the gear pump are splined to the engine. The piston pumps (hydrostatic system) provide flow for the hydrostatic drive system.
The machines have a two-section gear pump. The first section provides oil to the control valve (work tool). The second section of the gear pump provides charge oil for the hydrostatic system, oil for the optional Gear Motor (air conditioner) (22), oil for the optional Solenoid Valve and Mounting Group (quick coupler) (12), and oil for the pilot system.
Oil from the first section of the gear pump flows to the control valve (work tool). If no hydraulic circuits are active, the oil flows to the tank. This oil is not filtered by the oil filter.
Oil from the second section of the gear pump flows to the optional Gear Motor (air conditioner) (22). The oil then flows to the Gear Motor (fan drive) (17). The oil then flows through the hydraulic oil filter (16). Then, the oil flows to the Piston Pump (hydrostatic system) (23) .
Oil from the Piston Pump (hydrostatic system) flows to the Pilot Valve (hydrostatic system) (1) and to the Pilot Valve (work tool) (2). The pilot operated hydraulic controls are used to route pilot oil to Piston Pump (hydrostatic system) (23) and to Control Valve (work tool) (11) .
The pilot oil moves the swashplates in the piston pump in order to control Piston Motor Group (hydrostatic system) for the right side (21) and Piston Motor Group (hydrostatic system) for the left side (19). The pilot oil shifts the spools in the Control Valve (work tool) (11) in order to operate the work tools.
Oil returns to return manifold (15) from the following components: the Pilot Valve (hydrostatic system) and Pilot Valve (work tool), the Piston Pump (hydrostatic system), the Piston Motor Group (hydrostatic left side) and Piston Motor Group (hydrostatic right side) and the optional Solenoid Valve and Mounting Group (quick coupler) Gear Motor (Refrigerant Compressor). The oil can flow to the hydraulic oil cooler from the return manifold.
Hydraulic Supply System
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| Illustration 2 | g01114099 |
The Multi Terrain Loader hydraulic schematic (1) Pilot Valve (hydrostatic system) (2) Pilot Valve (work tool) (3) Diverter Valve (automatic level control valve RAISE) (4) Lift Cylinder (Left side) (5) Lift Cylinder (Right side) (6) Tilt Cylinder Group (Left side) (7) Tilt Cylinder Group (Right side) (8) Quick disconnects for the "A2" auxiliary circuit (9) Quick disconnects for the "A1" auxiliary circuit (10) Coupler Cylinder Group (11) Control Valve (work tool) (12) Solenoid Valve and Mounting Group (quick coupler) (13) Pressure Switch (optional backward travel alarm) (14) Accumulator (15) Return Manifold Gp (16) Hydraulic oil filter (17) Gear Motor (fan drive) (18) Hydraulic oil cooler (19) Piston Motor Group (hydrostatic left side) (20) Solenoid Valve and Mounting Group (21) Piston Motor Group (hydrostatic right side) (22) Gear Motor (air conditioner) (23) Piston Pump (hydrostatic system) (24) Gear Pump (25) Hydraulic Tank Gp | |
The hydraulic oil tank (25) stores the hydraulic oil for the machine. The hydraulic tank supplies oil to the hydrostatic system, the work tool hydraulic system, and the pilot hydraulic system.
A strainer is located inside the oil tank on the end of the supply line. The tank is not pressurized. A hose connects the tank to a breather.
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| Illustration 3 | g01061951 |
(26) Hydraulic tank filler cap (27) Hydraulic tank sight gauge | |
The sight gauge (27) is located on the right side of the machine below the filler cap (26). Maintain the oil level approximately in the middle of the sight gauge. Refer to the Operation and Maintenance Manual, SEBU7732, "Hydraulic System Oil Level - Check" for more information.
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| Illustration 4 | g01061952 |
(25) Hydraulic tank (26) Filler cap (28) Oil temperature sender | |
An oil temperature sender (28) is located on the bottom of the hydraulic tank (25). When the hydraulic oil temperature exceeds 102° ± 3°C (216° ± 5°F), the sender will activate the indicator light that is located on the left control panel. When the hydraulic oil temperature cools to a temperature of approximately 90 °C (194 °F), the sender will deactivate the indicator light.
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| Illustration 5 | g01061954 |
(23) Piston Pump (hydrostatic system) (24) Gear Pump | |
Hydraulic oil from hydraulic tank (25) flows into gear pump (24). The gear pump is driven by a common drive shaft that runs through the piston pump (hydrostatic system) (23). The gear pump supplies oil to the hydraulic system and to the hydrostatic system.
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| Illustration 6 | g01061958 |
(17) Gear Motor (fan drive) (29) Test port and fill port | |
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| Illustration 7 | g01061960 |
(17) Gear Motor (fan drive) (29) Test port and fill port (30) Relief valve (31) Check valve | |
Hydraulic oil for the Gear Motor (fan drive) (17) is supplied by the gear pump. Hydraulic oil from the hydraulic oil tank flows to the front section of the gear pump. The oil flows from the gear pump to the gear motor. The flow of oil through the gear motor turns the fan that cools the hydraulic oil that passes through the oil cooler. The fan also cools the coolant that flows through the radiator.
The fan motor will rotate in direct relation to the amount of hydraulic oil flow until the hydraulic oil pressure reaches the setting for the relief valve (30). The relief valve allows the excess oil to bypass the gear motor. The relief valve for the 267B is set to 1900 ± 100 kPa (275 ± 15 psi). The setting for the relief valve for the 277B and the 287B is 4460 ± 100 kPa (645 ± 15 psi).
The check valve (31) allows the gear motor to spin freely after the engine is turned off.
The test port and fill port (29) is used to test for contaminants in the hydraulic oil. For more information on the oil sample port, refer to Hydraulic System Testing and Adjusting, RENR4887, "Hydraulic Oil Contamination Test". The port is also used to pump oil into the piston pump. For more information on the fill port, refer to Hydraulic System Testing and Adjusting, RENR4887, "Filling and Flushing the Hydrostatic System Test".
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| Illustration 8 | g01061961 |
(16) Hydraulic oil filter (32) Differential pressure indicator | |
Hydraulic oil then flows out of the gear motor and into the hydraulic oil filter (16). The hydraulic oil filter is located at the rear of the left side of the engine compartment. The oil filter is a five micron filter. The hydraulic oil filter removes any particles that could damage the piston pump. From the oil filter, the hydraulic oil flows into the front section of the Piston Pump (hydrostatic system).
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| Illustration 9 | g01061964 |
(16) Hydraulic oil filter (32) Differential pressure indicator (33) Filter bypass valve | |
The oil filter contains a bypass valve. Bypass valve (33) opens when a differential pressure of 345 kPa (50 psi) is reached. Differential pressure indicator (32) will close when the differential pressure reaches 290 ± 15 kPa (42 ± 2 psi). When the differential pressure indicator closes, an electrical signal causes the light on the right control panel to illuminate. For more information about the alert indicators, refer to the Operation and Maintenance Manual, SEBU7732, "Alert Indicators".
Interlock System
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| Illustration 10 | g01114108 |
Multi Terrain Loader hydraulic schematic (1) Pilot Valve (hydrostatic system) (2) Pilot Valve (work tool) (3) Control Valve (work tool) (4) Solenoid Valve Group (5) Solenoid Valve Group (hydrostatic system) (6) Solenoid Valve Group (work tool) (7) Return Manifold Gp (8) Solenoid Valve Group (9) Hydraulic oil filter (10) Gear Motor (fan drive) (11) Hydraulic oil cooler (12) Piston Motor Group (hydrostatic left side) (13) Solenoid Valve and Mounting Group (parking brake) (14) Piston Motor Group (hydrostatic right side) (15) Gear Motor (air conditioner) (16) Piston Pump (hydrostatic system) (17) Gear Pump (charge oil, implement, air conditioner and fan drive) (18) Hydraulic Tank Gp | |
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| Illustration 11 | g01061968 |
(1) Pilot Valve (hydrostatic system) (2) Pilot Valve (work tool) (5) Solenoid Valve Group (hydrostatic system) (6) Solenoid Valve Group (work tool) | |
There are five solenoid valves for the interlock system on the Multi Terrain Loaders. The interlock system includes the following solenoids: the Solenoid Valve Group (hydrostatic system) (5), the Solenoid Valve Group (work tool) (6), Solenoid Valve Group (4) and Solenoid Valve Group (8) and Solenoid Valve and Mounting Group (parking brake) (13) .
The Solenoid Valve Group (hydrostatic system), the Solenoid Valve Group (work tool), and the Solenoid Valve and Mounting Group (parking brake) are energized under the following conditions:
- The seat must be occupied.
- The arm bar must be in the DOWN position.
- The parking brake switch must be disengaged.
The Solenoid Valve Group (hydrostatic system) (5) is located on the Pilot Valve (hydrostatic system) (1). The solenoid valve allows the flow of hydraulic signal oil to the pilot operated hydraulic control. When the solenoid is de-energized, no hydraulic signal oil flows to the hydraulic control.
The Solenoid Valve and Mounting Group (parking brake) (13) is located under the cab on the left side of the machine. The solenoid valve allows the flow of pilot hydraulic oil to the brakes. The parking brakes are located on piston motors (12) and (14) .
When the solenoid is de-energized, the flow of pilot hydraulic oil is blocked. Hydraulic oil from the parking brake actuators drains through the solenoid valve to the hydraulic tank. This allows the force of the actuator spring to engage the brakes. When the solenoid is energized, pilot hydraulic oil flows into the parking brakes. The oil pressure overcomes the force of the spring in order to disengage the parking brakes.
The Solenoid Valve Group (work tool) (6) is located on the Pilot Valve (work tool) (2). The solenoid valve allows the flow of pilot hydraulic oil to the pilot operated hydraulic control. When the solenoid is de-energized no flow of pilot hydraulic oil reaches the hydraulic control.
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| Illustration 12 | g01061970 |
(3) Control Valve (work tool) (4) Solenoid Valve Group (8) Solenoid Valve Group | |
The Solenoid Valve Group (4) and Solenoid Valve Group (8) are located on the Control Valve (work tool) (3). The solenoid valves are electronically activated. The valves enable the flow of pilot hydraulic oil to the auxiliary spool in the control valve.
The Gear Pump (17) supplies the hydraulic oil flow for the pilot system and the brake system. After the oil flows through the speed sensing valve, the signal oil to the Pilot Valve (hydrostatic system) (1) should be proportional to the engine rpm.
Return Manifold System
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| Illustration 13 | g01114116 |
Multi Terrain Loader hydraulic schematic (1) Pilot Valve (hydrostatic system) (2) Pilot Valve (work tool) (3) Control Valve (work tool) (4) Solenoid Valve and Mounting Group (quick coupler) (5) Return Manifold Gp (6) Hydraulic oil filter (7) Gear Motor (fan drive) (8) Hydraulic oil cooler (9) Piston Motor Group (hydrostatic left side) (10) Solenoid Valve and Mounting Group (parking brake) (11) Piston Motor Group (hydrostatic right side) (12) Gear Motor (air conditioner) (13) Piston Pump (hydrostatic system) (14) Gear Pump (15) Hydraulic Tank Gp | |
Oil flows to the Return Manifold Gp (5) from the following components: Gear Motor (air conditioner) (12) the Pilot Valve (work tool) (2), the Pilot Valve (hydrostatic system) (1), Solenoid Valve and Mounting Group (parking brake) (10), Solenoid Valve and Mounting Group (quick coupler) (4), the Piston Pump (hydrostatic system) (13) and the Piston Motor Groups (hydrostatic system) (11) and (9) .
The return manifold provides a common junction for the hydraulic oil prior to returning to the hydraulic tank. The return manifold also routes the oil to the hydraulic oil cooler (8) in order to keep the oil from getting too hot.
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| Illustration 14 | g01061976 |
(5) Return Manifold Gp (16) Return oil from the Solenoid Valve and Mounting Group (quick coupler) (17) Return oil from the Pilot Valve (hydrostatic system) (18) Return oil to the hydraulic oil cooler (19) Return oil from the case of the Piston Pump (hydrostatic system) (20) Bypass check valve of the oil cooler (21) Hydraulic system drain valve (22) Return oil from the Piston Motor Group (hydrostatic left side) (23) Return oil from the Piston Motor Group (hydrostatic right side) (24) Return oil to the hydraulic tank (25) Return oil from the hydraulic oil cooler | |
The hydraulic oil flows from line (18) to the hydraulic oil cooler. The cooling fan blows air across the oil cooler. The air cools the hydraulic oil. The cooling system is designed to maintain the hydraulic oil temperature at a temperature of approximately 50° ± 10°C (120° ± 20°F). The oil flows to line (25) on the return manifold (5). Then, the oil flows through line (24) to the tank.
The bypass check valve (20) is located in the return manifold. The bypass check valve prevents high pressure oil from entering the oil cooler when the engine is first started. The bypass check valve opens when the oil pressure inside the cooler exceeds 172 kPa (25 psi). The hydraulic oil flows through the check valve to line (24) to the hydraulic tank (15) .
The hydraulic system drain valve (21) is mounted in the return manifold. The drain valve is used to drain approximately 90% of the hydraulic oil from the lines, valves and the tank. A hose connects to the valve. The hose allows the oil to be drained into an approved receptacle through an opening in the belly guard.
Hydraulic Quick Coupler
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| Illustration 15 | g01114118 |
Multi Terrain Loader hydraulic schematic (1) Coupler Cylinder Group (2) Solenoid Valve and Mounting Group (quick coupler) (3) Return Manifold Gp (4) Gear Pump (5) Hydraulic Tank Gp | |
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| Illustration 16 | g01061982 |
(1) Coupler Cylinder Group (6) Coupler pins | |
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| Illustration 17 | g01061984 |
(7) Control switch for the work tool coupler | |
If the machine is equipped with a hydraulic work tool Quick Coupler Arrangement, the control switch (7) for the work tool coupler will be located on the upper left hand console. Refer to the Operation and Maintenance Manual, SEBU7732, "Machine Operation" for information on the operation of the hydraulic quick coupler.
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| Illustration 18 | g01061989 |
The Solenoid Valve and Mounting Group (quick coupler) (2) is located on the right side at the rear of the machine. The control valve may be mounted on the rear bulkhead on two threaded bosses. The control valve may be mounted onto a bracket. The bracket is attached to the machine near the release lever that is for the engine access door. The mounting location is dependent on the machine configuration and the options.
When the operator presses the top of the control switch and the operator holds the top of the control switch for the work tool coupler, an electrical signal is sent to the solenoid on Solenoid Valve and Mounting Group (quick coupler) (2). The energized solenoid moves the spool in the control valve upward.
When the spool is shifted in the up position, the oil that is from the second section of the gear pump (4) flows through the valve. The oil then flows into the head ends of the Coupler Cylinder Group (1). The oil causes the cylinders of the Coupler Cylinder Group (1) to extend. When the cylinders extend, the cylinders cause the coupler pins (6) to move down. The work tool should then be attached to the coupler. Ensure that the work tool is fully engaged to the coupler before the work tool is used. Refer to the Operation and Maintenance Manual, SEBU7732, "Work Tool Coupler Control".
When the operator slides the red button on the control switch downward, and the operator presses the bottom of the control switch for the work tool coupler, an electrical signal is sent to the other solenoid on Solenoid Valve and Mounting Group (quick coupler) (2). The energized solenoid causes the spool in the control valve to shift downward.
When the spool is shifted in the down position, the oil that is from the second section of the gear pump (4) flows through the valve. The oil then flows into the rod ends of the Coupler Cylinder Group (1). The oil causes the cylinders of the Coupler Cylinder Group (1) to retract. When the cylinders retract, the cylinders cause the coupler pins (6) to move up. The work tool should then be detached from the coupler. Ensure that the work tool is fully disengaged from the coupler before the machine is moved. Refer to the Operation and Maintenance Manual, SEBU7732, "Work Tool Coupler Control".