Raise Cutting Unit
A three section gear pump is coupled to the piston (trac-
tion)pump.Thegearpumpsection farthestfromthepis-
ton pump supplies hydraulic flow to the lift/lower control
valve and the steering control valve. Hydraulic flow from
this pump section is delivered to the two circuits through
a proportional flow divider. The gear pump takes its suc-
tion from the hydraulic reservoir.
To raise the front cutting unit, the center lift lever on the
lift/lower control valve is pulled to allow valve shift in the
lift/lower control. This valve change allows hydraulic
pressure to the rod end of the front deck lift cylinders,
causing the cylinders to retract. As the cylinders retract,
the front deck raises. Oil from the piston end of the cylin-
der returns to the hydraulic reservoir. When the lift lever
is released, the lift cylinder is held in position.
When the cutting units are in a stationary position, flow
from the gear pump is by--passed through the lift/lower
control valve, counterbalance manifold, oil filter, and
traction charge circuit.
An adjustable counterbalance valve maintains back
pressure on the lift cylinders. Arelief valve located inthe
lift/lower control valve limits circuit pressure. Excess cir-
cuit flow is routed to the oil filter and then to the traction
charge circuit.
To raise a side cutting unit, the appropriate lift lever on
the lift/lower control valve is pulled to allow valve shift in
the lift/lower control. This valve change allows hydraulic
pressure to the piston end of the lift cylinder and causes
the shaft to extend, raising the cutting unit. Oil from the
rod end of the cylinder flows to the traction charge cir-
cuit.Whentheliftleverisreleased,theliftcylinderisheld
in position.
Groundsmaster 4000--D
Page 4 -- 13
Hydraulic System (Rev. B)
| Categories | Lawn Mower Manual, Toro Lawn Mower Manual |
|---|---|
| Tags | Toro Groundsmaster 4000 D |
| Download File |
|
| Document Type | Service Manual |
| Language | English |
| Document File Type | |
| Publisher | toro.com |
| Wikipedia's Page | Toro Company |
| Copyright | Attribution Non-commercial |
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