Testing The Steering Circuit-Charge Pump Flow (Machine Serial Numbers Above 316000000) - Toro Groundsmaster 3280-D Service Manual

Testing the Steering Circuit–Charge Pump Flow (Machine Serial
Numbers above 316000000)
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Test Procedure
Groundsmaster ® 3280-D/3320
05138SL Rev B
The charge pump is designed to satisfy the steering cylinder needs (at full
speed). The charge pump flow test compares fluid flow at No Load with fluid
flow Under Load. A drop in flow under load of more than 15% indicates the
gears and wear plates in the pump have worn. Continued operation with a worn
pump can generate excessive heat and cause damage to the seals and other
components in the hydraulic system.
Special Equipment Required: Flow meter with pressure gauge that has at least a
16 L/minute (5 gallons/minute) capacity.
1. Park the machine on a level surface with the PTO switch off, lower the cutting
deck, shut off the engine, and set the parking brake.
2. Read all Warning, Cautions, and precautions listed at the beginning of this
section.
Before opening the hydraulic system, operate all the hydraulic
controls to release system pressure and avoid injury from the
pressurized hydraulic fluid; refer to
Hydraulic System (page
Figure 72
CAUTION
Releasing Pressure from the
5–6).
Page 5–69 Hydraulic System: Testing the Hydraulic System