Elliott Digger Derrick, Operation & Maintenance Manual, Page: 195 / 376

Changing Hydraulic Oil EEC-0018 V1.1
Changing Hydraulic Oil
Drain and refill the hydraulic system every six months unless an alternate interval has
been established by oil analysis.
A. Bring the oil to operating temperature by running the crane functions.
B. With all controls in neutral position, turn the truck engine off.
C. Remove the drain plug from the tank bottom. If the oil is extremely dirty or
contaminated, crack open fittings at high points on the system to vent the lines. Be
sure to retighten the fittings prior to starting the truck engine.
D. Thoroughly clean dirt from the access cover on the top of the tank and remove the
cover.
E. Clean out any sediment inside the tank.
F. Remove the suction strainer. Soak in solvent and blow off with compressed air
before reinstalling.
G. Reinstall the cover on the tank top, replace gasket as required.
H. Replace the filter element.
I. Replace the breather.
J. Clean metal particles from the drain plug and reinstall.
K. Fill the hydraulic tank to the proper level with approved, filtered hydraulic oil-use 10
micron filter.
L. Make sure the suction line shut off valve is open before starting the engine;
otherwise the pump will produce cavitation and destroy itself.
M. Start the engine, engage the PTO and let the pump run a couple minutes with no
load at low RPM.
N. Gradually increase speed and operate all functions. Operation may be sluggish or
erratic as air is purged.
O. Once the functions are operating smoothly, stow the boom and outriggers and then
stop the engine.
P. Fill the hydraulic tank to the full level on the sight gauge.