During Lowering - Toyota 7FBEF 15 Service Manual

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2. During lowering (lift solenoid valve: ON)
(1) When the key switch is turned ON, the lift solenoid valve is turned on. The poppet moves to the
right side in the figure to open the check valve. Then the hydraulic oil at the lower portion of the lift
cylinder flows through the C1 port to the lower side of the logic valve and the solenoid valve, and to
the upper side of the logic valve and the lift spool.
(2) Therefore, the relation of the pressures when the spool is stationary with the key switch ON will be
as follows: C1 pressure = Logic valve upper side pressure = Logic valve lower side pressure.
(3) Then operating the lift lever to the lowering side pushes the lift spool to the right in the figure and
opens the circuit between the C1 and tank ports. Since part A of the logic valve has an orifice, the
hydraulic oil between the lower side of the logic valve and the spool flows to the tank port.
Meanwhile, the hydraulic oil at the C1 port does not flow down quickly because it is choked by the
logic valve orifice.
Orifice
Logic valve lower side
Lift spool
Part A
Logic valve upper side
Pump port
Check valve
C1
Logic valve
Tank port
Lift load check valve
Poppet
Solenoid valve
Lift cylinder