Procedure For Gear Pump Flow Test - Toro Groundsmaster 4500-D Series Service Manual

Gear Pump Flow (Using Tester with Pressure Gauge & Flow Meter)
(continued)

Procedure for Gear Pump Flow Test

Groundsmaster ® 4500-D/4700-D
19245SL Rev A
The gear pump flow test should be performed to make sure that the mow,
steering, lift/lower, cooling fan and traction charge circuits have adequate
hydraulic flow. Gear pump sections are illustrated in
pump section provides hydraulic flow for cutting decks 2, 3 and 5 (also deck 7
on the GM4700-D). The second gear pump section provides hydraulic flow for
cutting decks 1 and 4 (also deck 6 on the GM4700-D). The third gear pump
section provides hydraulic flow for the steering, lift/lower and traction charge
circuits. The fourth gear pump section provides hydraulic flow for the engine
cooling fan circuit.
Note: Over a period of time, the gears and wear plates in the gear pump can
wear. A worn pump will by pass oil and make the pump less efficient. Eventually,
enough oil loss will occur to cause circuit problems (e.g. cutting deck motors
stalling under heavy cutting conditions, lift or steering problems). Continued
operation with a worn, inefficient gear pump can generate excessive heat and
cause damage to the seals and other components in the hydraulic system.
Prevent personal injury and/or damage to equipment. Read all
WARNINGS, CAUTIONS and Precautions for Hydraulic Testing at the
beginning of this section.
1. Make sure hydraulic oil is at normal operating temperature by operating
the machine for approximately ten (10) minutes. Make sure the hydraulic
reservoir is full.
2. Park machine on a level surface with the cutting decks lowered and off. Make
sure engine is off and the parking brake is applied.
3. Raise and support operator seat to gain access to gear pump.
g308640
1. First gear pump section (decks 2, 3, 5 and
7)
nd
2. 2 gear pump section (decks 1, 4 and 6)
CAUTION
Figure 91
3. 3 rd
and charge)
th
4. 4
Page 5–83
Figure 91. The first gear
gear pump section (steering, lift/lower
gear pump section (engine cooling fan)
Hydraulic System: Testing