Broderson RT-300-2G, Operation And Maintenance Manual

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3-17
PURGING THE HYDRAULIC SYSTEM
If excessive water or other contamination is found in the hydraulic oil, the source should be
found and fixed, and the oil should be changed. However, there will still be a large quantity
of contaminated oil in the hydraulic cylinders. This oil should be purged by the following
procedure:
1.
After the reservoir is cleaned and the filter replaced, fill the reservoir with clean oil.
Do not start the engine or move any controls until the proper point in this procedure.
2.
Monitor the oil level and do not allow it to fall below 15" (40 cm) from the top of the fill
neck during this procedure.
3.
Run the engine at low idle during this procedure to minimize oil loss and the
possibility of pump damage from cavitation due to low oil level.
4.
Remove the hook from the load line and pull the load line out of the boom tip.
5.
With the engine still stopped, close the shutoff valve on the two 1-½" (3.8 cm) return
lines, but not on the 3" (7.6 cm) suction line. Disconnect all six return line hoses near
the reservoir and run them into a waste oil sump or barrel.
6.
Start the engine and run at low idle for about 17 seconds after flow starts from return
lines into waste oil sump. This should purge about 7 gallons (27 L) from the pressure
and return lines, which is about what they contain. Stop the engine.
7.
Reconnect the return lines, open the shutoff valves and fill the reservoir.
8.
Run the engine at low idle for thirty minutes to filter the oil in the reservoir.
9.
Disconnect the steering return hose from the steering control unit at the point where it
connects at the tank. Cap the fitting on the tank tee. Run the hose into the waste oil
sump. Open all shutoff valves.
10. Run the engine at low idle and turn the steering wheel fully to the right, then fully to
the left and then back to straight.
11. Reconnect the steering return hose. Be sure all shutoff valves are open.
12. Position the crane so that the boom may later be fully extended, the outriggers fully
extended and the boom rotated and fully topped up while retracted. Do not operate
these functions until the proper step.
13. Disconnect the return hose from the return filter inlet and cap the fitting on the filter.
Run the hose into the waste oil sump. Shutoff valves must be open.
14. Pull the BOOM RAISE lever fully back in the raise position and start the engine. Run
at low idle until the boom is fully topped up, then stop engine quickly.
15. Reconnect the return hose and open the shutoff valve.
16. Lower the boom back to the stowed position, and stop engine.
17. Close the center shutoff valve on the reservoir and disconnect the two return lines
from it. Run the hoses into the waste oil sump.
Courtesy of Crane.Market