Toro Groundsmaster 4000-D Service Manual page 81

Mow Circuit Problems
Problem
None of the cutting decks will oper-
ate.
NOTE: To engage the mow circuit,
the seat must be occupied, the cut-
ting deck(s) must be fully lowered,
the traction speed must be in the
LOW (mow) position and the PTO
switch must be ON.
One cutting deck will not operate.
All cutting decks operate slowly.
Cutting deck stops under load.
Groundsmaster 4000--D/4010--D
Possible Cause
Electrical problem exists that prevents PRV solenoid valve in PTO
manifolds from being energized (see Chapter 5 -- Electrical Sys-
tem).
Front two (2) gear pump sections for mow circuits are worn or dam-
aged.
Electrical problem (e.g. solenoid coil in PTO manifold, cutting deck
position switch) exists (see Chapter 5 -- Electrical System).
Cutting deck problem exists (e.g. drive belt, deck spindle).
System pressure to the affected cutting deck is low.
Woodruff key on affected deck motor is damaged.
Proportional relief valve (PRV) in PTO manifold for affected deck is
faulty.
Cartridge valve in PTO manifold for affected deck is damaged or
sticking.
Deck motor for affected deck is damaged (NOTE: if appropriate,
transfer a suspected damaged motor to another cutting deck. If prob-
lem follows the motor, motor is faulty and needs repair or replace-
ment).
Gear pump section for affected deck is worn or damaged.
Engine RPM is low.
All deck motors are worn or damaged.
Front two (2) gear pump sections for mow circuits are worn or dam-
aged.
Proportional relief valve in PTO manifold for affected deck is by--
passing.
Deck motor has internal leakage (by--passing oil).
Gear pump section for affected deck is worn or damaged.
Page 4 - - 35 Hydraulic System