Lift Circuit Problems - Toro Groundsmaster 4500-D Series Service Manual

Lift Circuit Problems

Troubleshooting:
Problem
Cutting decks will not raise.
Note: Seat must be occupied in order to raise
the cutting decks.
Cutting decks raise, but will not stay up.
Note: Lift cylinders cannot provide an
absolutely perfect seal. A cutting deck will
eventually lower if left in the raised position
during storage.
Cutting decks will not lower.
Possible Cause
Engine RPM is too low.
Hydraulic oil level in reservoir is low (NOTE:
Other hydraulic systems are affected as well).
Electrical problem exists (see
Electrical System (page
Lift arm pivots are binding.
Lift/lower circuit relief valve in lift control
manifold is stuck open.
Solenoid valve in lift control manifold is
damaged or sticking.
Lift cylinder(s) is (are) damaged.
Flow divider (FD) in fan control manifold is
faulty.
The third gear pump section is worn or
damaged (NOTE: A worn or damaged third
gear pump section will also affect the traction
charge and steering circuits).
Lift circuit hydraulic lines or fittings are leaking.
Cartridge valve in lift control manifold is stuck
open.
Lift cylinder for affected deck is damaged.
Lift arm pivots are binding.
Engine RPM is too low.
Electrical problem exists (see
Electrical System (page
Proportional relief cartridge valve (TS) in lift
control manifold is damaged or sticking.
Lift cylinder for affected deck is damaged.
Page 3–8
Chapter 6:
6–1)).
Chapter 6:
6–1)).
Groundsmaster ® 4500-D/4700-D
19245SL Rev A