TM 5-3805-280-24-2
Hydraulic System
12. Check pump regulator adjustments. (See Hydraulic
Pump Regulator Test and Adjustments in Group
9025-25.)
TX,33,UU3781
1921SEP984/4
HYDRAULIC PUMP AND DRIVE GEARBOX
START-UP PROCEDURE
IMPORTANT: Hydraulic pump and drive gearbox will
be damaged if not filled with oil before
starting engine. Procedure must be
performed whenever a new pump or
gearbox is installed or oil has been
drained from the pump, gearbox or
hydraulic oil tank.
Procedure is to ensure the pumps and
gearbox are filled with oil and air is bled
from suction side of pumps to prevent
1. Remove air bleed plugs (C) from the top of pump
regulators to allow housing to fill with oil from the
hydraulic oil tank and to let air escape.
2. When pump housing is full of oil, install plugs.
3. As necessary, add oil to hydraulic oil tank until it is
between marks on sight glass. (See Hydraulic Oil in
Group 0004.) Tighten tank cap. Tighten vent plug.
4. Start engine and run at slow idle. Slowly raise boom to
full height and then lower to pressurize hydraulic oil
tank.
5. Purge air from the hydraulic system by slowly
operating each function through three cycles. Air in
pilot circuits are purged automatically.
6. Fill pump drive gearbox with oil through filler pipe (B)
so level is above "H" mark on dipstick (A). (See Diesel
33
Engine and Pump Gearbox Oils in Group 0004.)
3360
23
A--Dipstick
B--Filler Pipe
C--Air Bleed Plugs
TX,33,UU3782
1921SEP981/1
21-65
