Flush Hydraulic System - Toro 30821 Service Manual

Flush Hydraulic System

IMPORTANT: Flush the hydraulic system any time
there is a severe component failure or if the system
is contaminated (oil appears milky, black, or con-
tains metal particles).
IMPORTANT: Flush hydraulic system when chang-
Ing from petroleum base hydraulic fluid to a biode-
gradable fluid such as Toro Biodegradable
Hydraulic Fluid. Operate machine under normal op-
erating conditions for at least four (4) hours before
draining.
IMPORTANT: If a component failure occurred in the
traction circuit, refer to Traction Circuit (Closed
Loop) Component Failure in the General Informa-
tion section for information regarding the impor-
tance of removing contamination from the traction
circuit.
1. Park machine on a level surface. Lower cutting units,
stop engine, and engage parking brake. Remove key
from the ignition switch.
WARNING
Before disconnecting or performing any work
on the hydraulic system, all pressure in the
system must be relieved. See Relieving Hy-
draulic System Pressure in the General Infor-
mation section.
IMPORTANT: Make sure to clean around any hy-
draulic connections that will be disassembled.
2. Drain hydraulic tank (see Change Hydraulic Fluid).
3. Drain hydraulic system. Drain all hoses, tubes, and
components while the system is warm.
4. Change and replace oil filter (see Replace Hydraulic
Oil Filter).
5. Inspect and clean hydraulic oil tank (see Hydraulic
Tank Inspection).
Groundsmaster 3500- D
6. Reconnect all hydraulic hoses, lines, and compo-
nents that were disconnected while draining system.
NOTE: Use only hydraulic fluids specified in Check Hy-
draulic System Fluid. Other fluids may cause system
damage. If changing to biodegradable fluid, use Toro
Biodegradable Hydraulic Fluid for this step.
7. Fill hydraulic tank with new hydraulic fluid (see
Change Hydraulic Fluid).
8. Disconnect fuel stop solenoid lead to prevent the en-
gine from starting. Make sure traction pedal and the lift
control lever are in the neutral position.
9. Turn ignition key switch and engage starter for ten
(10) seconds to prime the traction and gear pumps. Wait
fifteen (15) seconds to allow the starter motor to cool and
then repeat cranking procedure again.
10.Connect electrical connector on fuel stop solenoid.
11. Start engine and let it idle at low speed (1750 + 50
RPM) for a minimum of 2 minutes. Increase engine
speed to high idle (3050 + 50 RPM) for a minimum of 1
minute under no load.
12.Raise and lower cutting units several times. Turn
steering wheel fully left and right several times.
13.Shut off engine and check for hydraulic oil leaks.
Check oil level in hydraulic tank and add correct amount
of oil if necessary.
14.Operate the machine for 2 hours under normal oper-
ating conditions.
15.Check condition of hydraulic oil. If the new fluid
shows any signs of contamination, repeat steps 1
through 14 again until oil is clean. If changing to biode-
gradable fluid, repeat steps 1 through 14 again at least
once and until the oil is clean.
16.Assume normal operation and follow recommended
maintenance intervals.
Page 4 - 63 Hydraulic System (Rev. G)