Hydraulic Tank
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| Illustration 1 | g03510139 |
Hydraulic oil tank and filters (1) Hydraulic oil tank (2) Bypass check valve and hydraulic tank return filters (3) Breathers (4) Main pump case drain filter (5) Lower motor case drain filter (6) Swing system case drain filter | |
The return oil flows into the hydraulic tank from the following components.
- Return filters
- Case drain filters
- Bypass check valve
- Upper and lower main control valves
- Pilot manifold
Three return filters are mounted on the rear surface of the hydraulic tank.
The oil passes through element of the return filter and flows into tank chamber. Thereafter, the oil passes through the suction filter and the oil is delivered to the pumps through the suction line .
The air breather is mounted on the upper surface of the hydraulic tank. The air breather maintains a certain air pressure in the hydraulic tank regardless of the following circumstances :
- Change of air pressure in the hydraulic tank due to cylinder movement.
- Change of air pressure in the hydraulic tank capacity due to a temperature change.
Sight Gauge
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| Illustration 2 | g03510460 |
Sight gauge located on left front corner of reservoir (7) Full (8) Low | |
The sight gauge is located on the left front corner of the reservoir. A float inside the tube is used to indicate the oil level of the tank. In addition to the sight gauge, the machine is equipped with a low-level warning system. Before checking the hydraulic oil level of the machine establish the following conditions:
- Park the machine on a level surface.
- Raise the outriggers to the upright position.
- Move the stick and boom to the vertical position.
- The tip of the stick must be 8 feet from the ground.
Hydraulic Oil Fill
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| Illustration 3 | g03510462 |
Hydraulic oil fill (9) Quick coupler (10) Hand pump (11) Capped fitting | |
The hydraulic oil fill valve is located on the lower portion of the machine opposite the lower manifold. Fill the hydraulic reservoir by using one of the following procedures:
- Connect with a hose to capped fitting (11) for hand pumping from a pail. Hand pump (10) is located inside the compartment of the lower frame.
- Connect to quick-coupling (9) if filling with a power fill station.
Filters
The elements are installed in the return chambers that are inside the hydraulic tank. Oil flows from the return oil manifold into the filter elements. The return oil flows into the return oil filter housing at the top. Then, the oil flows from the outside to the inside through the filter elements.
Clean hydraulic oil leaves the filter elements through the diffuser below the oil level in the hydraulic tank. The diffuser is positioned to prevent the formation of foam in the oil.
If the filter becomes full of debris, the flow restriction causes a pressure increase inside the filter. The pressure oil causes the bypass valve to open. Then, the oil goes past the elements directly into the hydraulic tank.
The hydraulic tank also houses three separate case drain filters for the following systems:
- Swing System
- Drive Motors and Lower Manifold
- Main Pumps