334
TRIM AND TILT
MODES OF OPERATION
MODES OF OPERATION
The trim/tilt hydraulic assembly achieves trim and
tilt moveme nt through the following mod es of
operation.
Trim-OUT / Tilt-UP Mode
When the UP switch is pressed, the trim/tilt motor
rotates clockwise (as viewed from pump end) and
turns the pump gears.
Fluid pressure pushes the UP che ck valve off its
seat, and fluid passes through the valve to the
bottom of all cylinders, pushing the pistons UP.
Fluid is pushed fr om the top of the tilt cylinder by
the pisto n a nd returns to the pu mp through the
open DOWN check valve.
In the trim ran ge, flu id is pushed from th e top of
the trim cylinders by the pistons and returns to the
reservoir.
Only f luid f rom the top o f t he tilt cylinder is
returned to the pump. Because the cylind er rod
displaces some fluid, that volume is less than the
volume of th e bottom of the tilt cylinder. So, add i-
tional fluid is drawn into the pump from the reser-
voir.
When all the cylinder s are comp letely extend ed,
the pressure in creases until the UP relief valve
opens at th e tilt-up stall pressure (approximately
1500 psi (10342 kPa)).
1. Up shuttle valve
2. Down shuttle valve
3. Down check valve
4. Up check valve
5. Tilt cylinder
6. Trim cylinders
7. Up relief valve
DRC3462
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