Toro Groundsmaster 3500 30807 Service Manual page 109

Cutting Deck Circuit Testing − Deck Motor Effi-
ciency/Case Drain Test
The deck motor efficiency/case drain test is the second
in a series of tests recommended to check cutting deck
circuit performance. Over a period of time, a deck motor
can wear internally. This test measures case drain
volume while restricting flow across the motor ports.
Case drain volume under load of more than 9% of total
motor flow indicates the gears and wear plates in the
motor have worn. A worn motor may by−pass hydraulic
fluid to its case drain causing the motor to be less effi-
cient. Eventually, enough fluid loss will cause the deck
motor to stall under heavy cutting conditions. Continued
operation with a worn, inefficient motor can generate ex-
cessive heat, cause damage to seals and other compo-
nents in the hydraulic system, and affect quality of cut.
Special Equipment Required:
S Flow Meter with Pressure Gauge that has at least
a 12 GPM (45 LPM) capacity.
S Phototach (non−contact tachometer).
1. Make sure hydraulic fluid is at normal operating tem-
perature by operating the machine for approximately 10
minutes. Make sure the hydraulic tank is full.
2. Park the machine on a level surface with the cutting
units lowered and PTO switch off. Make sure engine is
off, transport/mow switch in in the MOW position, and
the parking brake is disengaged.
3. Read Precautions for Hydraulic Testing in this
chapter.
4. Make sure that traction pedal is adjusted to the neu-
tral position.
NOTE: The deck motors are connected in series. If a
faulty deck motor is not obvious (based on quality of cut
issues) you may have to test all three motors in the cir-
cuit. If testing all cutting deck motors, start with the first
motor in the series (front left).
5. Remove the deck motors from all cutting decks (Fig.
32).
6. Disconnect the return hose from the motor. The re-
turn hose is the first hose counterclockwise of the smal-
ler (center) case drain hose (Fig. 33).
7. Install hydraulic tester between the motor and the
disconnected return hose. Make sure the tester flow
control valve is fully open.
8. Disconnect hose from deck motor case drain at the
bulkhead T−fitting (Fig. 33). Plug the T−fitting to prevent
system contamination. Place open end of disconnected
case drain hose into a drain pan.
Groundsmaster 3500
2
33 to 36 ft−lb (3.7 to 4.0 N−m)
1. Deck motor
3
5 6
4
8
1. Deck motor
2. Rear case drain hose
3. Rear T−fitting
4. Front left
case drain hose
9. Two people are required to complete the following
steps. One person should sit in the operator's seat and
operate the machine while another person reads the
tester and measures deck motor case drain volume.
Start the engine and move throttle to full speed (Diesel
engine = 3220 + 50 RPM, Gas engine = 3420 + 30
RPM). Engage the cutting units.
10.Verify with a phototach that the pump speed is ap-
proximately 2850 RPM.
11. Engage cutting decks and slowly close tester flow
control valve until a pressure of 2000 PSI (138 Bar) is
obtained.
Page 5 − 51
1
Figure 32
2. Motor mounting screws
2
7
1
RIGHT
FRONT
1
Figure 33
5. Front right
case drain hose
6. Front T−fitting
7. Rear return hose
8. Front left return hose
Hydraulic System