89
M2.0-1055-009
HYDRAULIC
Hydraulic Circuits
Refer to Figure 15982. Oil flow after CBVR will leave
the main manifold at port TE and flow into the back of
the double-acting piston type Tilt cylinders. That oil flow
will exert pressure on the piston and rod assemblies
inside of the tilt cylinders. This will cause the pistons to
exert pressure on oil contained in the front of the tilt
cylinders. That oil will be forced out the front of the tilt
cylinders, into port TR of the main manifold, across
SVTE and back to the reservoir. This entire action al-
lows the cylinder rods to "extend" out of the cylinder
housings, causing the mast to tilt down or away from
the power unit.
Tilt Back Circuit
Pressing on the upper part of the multi-task handle
thumb ball closes TBS (Tilt Back Switch). Refer to Fig-
ure 15859. When Tilt Back is selected SVTR will ener-
gize and shift fully. SPA will be ramped open to the
point required for tilt speed, and the pump motor will be
ramped up to the rpm required for tilt speed. Supply oil
after SPA will flow through the check portion of CBVE,
out port TR and into the front of the tilt cylinders. Some
of that oil flow will be applied as pilot pressure to the
blocking portion of CBVR.
Oil in front of the pistons inside the Tilt cylinders will be
pushed out and into port TE. Some of this oil flow will
be applied as relief pressure to the blocking portion of
CBVR. Both supply and return oil flow will force the
blocking portion of CBVR to open, allowing the oil en-
tering port TE to flow through SVTR and back to the
reservoir. This will cause the piston and rod assemblies
to "retract" into the cylinders causing the mast to tilt
back or towards the power unit. When the Tilt Back
command is removed, (TBS opened) SPA and the
pump motor are ramped closed/off and SVTR is de-
energized.
Figure 15859
Suction
Return
Relief
Pressure
Crown 2007 PF15675-9
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