Toro Reelmaster 3550-D Service Manual page 83

Cutting Unit Circuit Testing − Reel Motor Cross−
Over Relief Pressure Test (Reelmaster 3575−D)
1. Determine which cutting reel motor needs to be test-
ed by observing the machine during mowing.
2. Park machine on a level surface with the cutting units
lowered and reel engage switch OFF. Make sure engine
is off and mow/transport lever is in mow. Apply the park-
ing brake.
3. Read Precautions For Hydraulic Testing in this sec-
tion.
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
NOTE: The reel motors are connected in series. To iso-
late a faulty motor, all motors in the circuit may have to
be tested by starting with the first motor in the series.
4. On the reel motor to be tested, thoroughly clean mo-
tor inlet and outlet fittings and hydraulic hoses (Fig. 30).
Loosen and remove both hoses from fittings. Install a
tee fitting with a 5000 PSI (350 bar) pressure gauge be-
tween the fitting and hose for both the motor inlet and
outlet.
5. Make sure backlap knob on the hydraulic manifold is
in the MOW position and reel speed is set to maximum.
6. Insert a block of wood between cutting unit reel
blades and carrier frame of cutting unit being tested to
prevent reel from turning (Fig. 29).
7. Start engine and run at low idle speed. Check for any
hydraulic leakage from test connections and correct be-
fore proceeding with test.
8. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes. DO NOT engage cut-
ting units.
CAUTION
Adjacent cutting unit reels will rotate when per-
forming the cross−over relief pressure test. Keep
away from cutting units during test to prevent
personal injury from rotating reel blades. Do not
stand in front of the machine.
Reelmaster 3550−D/3555−D/3575−D
2
FRONT
1. Cutting unit motor
2. Motor inlet hose
9. One person should sit on the seat and operate the
machine while a second person closely monitors both
pressure gauges connected to the reel motor. Make
sure that engine speed is at low idle position (1400 + 50
RPM RPM) and engage the cutting units.
10.There should be a slight hesitation in pressure in-
crease on the inlet side of motor as the cross−over relief
valve opens. Record the pressure reading on both the
inlet and outlet side pressure gauges.
11. Disengage the cutting units and stop the engine.
12.Calculate the pressure differential between the two
gauges. If the pressure differential is not approximately
1450 PSI (100 bar), the cross-over relief valves on the
tested motor may be leaking or damaged. Inspect relief
valves in the reel motor and replace if necessary (see
Cutting Reel Motor Service − Reelmaster 3575−D in this
chapter).
13.After testing is completed, relieve cutting unit hy-
draulic system pressure (see Relieving Hydraulic Sys-
tem Pressure in the General Information section of this
chapter). Remove pressure gauges and tee fittings from
machine. Connect hydraulic hoses to reel motor fittings.
14.If necessary, test cross−over relief pressure on other
cutting reel motors.
15.Operate machine and check for leaks before return-
ing machine to service.
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OUT
IN
1
Figure 30
3. Motor outlet hose
Hydraulic System
3