TM 5-3825-226-24
As the pistons in the lift cylinders go down, they push
the oil from the rod ends through opening (17). The oil
pushes check valve (18) open and then goes through
opening (16) and the oil line to the control valve opening
(4). The rod end oil goes through the control valve and
through outlet (11) to the tank.
CARRY CHECK VALVE (CROSS SECTION)
15. Fitting (for vent line to control valve). 16. 011
line opening. 17. Opening (to the rod end of the
cylinder). 18. Check valve.
The rod end oil from the lift cylinder opens check
valve (18) only when valve spool (6) is in DOWN
position (C). Hole (7), in the valve spool, is in passage
(8) with the valve spool in HOLD position. Oil from the
spring chamber in check valve (18) is pushed through
fitting (15) and the oil line into passage (8). The oil in
passage (8) goes through hole (7), through the passage
in the center of the valve spool and out hole (5) into the
oil that goes through outlet (11) to the tank.
Move the lift cylinder lever to the UP position and it
moves valve spool (6) to UP position (A). Now, the oil
from the pump in the control valve goes out through
opening (4), through the oil line into opening (16) in the
carry check valve. The pump oil opens check valve
(18) and goes through opening (17) into the rod ends of
the lift cylinders. The pump oil in the rod ends pushes
the pistons and rods, connected to the water distributor,
and the water distributor goes up.
The pump oil through opening (16) pushes on the
step surface of check valve (18) to open the valve. The
pump oil opens the check valve because, when bowl
valve spool (6) is in UP position (A), hole (9) is then in
passage (8) and the oil in the spring chamber of check
valve (18) goes through fitting (15), the oil line and into
passage (8). The oil in passage (8) goes through hole
(9) out of hole (5) and into the oil that goes through
outlet (11) to the tank.
The HOLD position (B) for valve spool (6) stops the
oil in passage (8), in the oil line and fitting (15) and in
the spring chamber of check valve (18). The oil from
the rod ends of the lift cylinders in opening (16), of the
carry check valves, can not open the check valves and
this keeps the water distributor up until the lift cylinder
lever is moved.
RELIEF VALVES
Lift Cylinder Circuit
CONTROL VALVE
1. Oil line (from the pump). 2. Relief valve.
The relief valve (2) in the circuit for the lift cylinders
is in the scraper control valve. When the engine is
running, oil from the pump goes through line (1), with
the Tee test plug, and into the passage in the control
valve with relief valve (2).
The pressure setting of the relief valve can be
adjusted. The relief valve must be removed and
disassembled to change the amount of shims in the
valve.
Add shims for an increase or remove shims for a
decrease in the pressure setting of relief valve (2).
5-8
