Lift/Lower Circuit Problems - Toro Greensmaster TriFlex 3300 Service Manual

Lift/Lower Circuit Problems

Problem
Cutting units will not lift or lift slowly.
Front cutting units (#2 and #3) raise,
but will not stay up.
(NOTE: Lift cylinders and control
manifold check valves cannot pro-
vide an absolutely perfect seal. The
cutting units will eventually lower if
left in the raised position)
Center cutting unit (#1) raises, but
will not stay up.
(NOTE: Lift cylinders and control
manifold valves cannot provide an
absolutely perfect seal. The cutting
units will eventually lower if left in the
raised position)
Greensmaster 3300/3400
Possible Cause
Engine speed is too low.
Reservoir oil level is low.
Lift cylinder linkage is binding or broken.
Lift cylinder bushings are binding.
Relief valve in power steering valve is leaking or damaged (see
Steering/Lift Relief Valve Pressure Test in the Testing section of this
chapter).
Solenoid valve (S1) in lift control manifold is leaking or damaged
(not shifting to its energized position).
Lift cylinders leak internally.
Spool in power steering valve is hung up (see Power Steering
Valve Test in the Testing section of this chapter).
Rear gear pump section is worn or damaged (steering and charge
circuits affected as well) (see Steering/Lift Circuit Gear Pump Flow
Test in the Testing section of this chapter).
Solenoid valve (S3) in lift control manifold is leaking or damaged.
Front lift cylinders leak internally.
Solenoid valve (S4) in lift control manifold is leaking or damaged.
Center lift cylinder leaks internally.
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