Toro Groundsmaster 4700-D Service Manual page 74

Engine Cooling Fan Circuit Problems
Problem
Cooling fan runs only in forward di-
rection (fan does not run in reverse
direction).
Cooling fan does not rotate.
Cooling fan always rotates at slow
speed.
Cooling fan always rotates at fast
speed.
Hydraulic System
Possible Cause
Fan control manifold solenoid cartridge valve (S1) is faulty.
Electrical problem exists that prevents fan control manifold solenoid
valve (S1) operation (see Chapter 5 -- Electrical System).
Fan motor is worn or damaged.
Gear pump section (P4) is worn or damaged.
Fan control manifold cartridge valve seals are leaking.
Check valve in fan control manifold is not seating.
Fan control manifold proportional relief valve (TS) is stuck open.
Hydraulic fan motor is worn or damaged.
Fan control manifold proportional relief valve (TS) is faulty.
Electrical problem exists that prevents fan control manifold propor-
tional relief valve (TS) operation (see Chapter 5 -- Electrical Sys-
tem).
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