Toro Groundsmaster 7210 Service Manual page 101

Test Procedure
Groundsmaster 7210
16222SL Rev C
Perform the traction relief valve pressure test if you identify a traction circuit
problem. This test determines if a transmission relief valve operates correctly.
1. Ensure that the hydraulic fluid is at normal operating temperature.
2. Ensure that the traction drive is correctly adjusted for the N
Before disconnecting or doing any work on the hydraulic system,
release all the pressure in the system; refer to
from the Hydraulic System (page
3. Park the machine on a level surface, lower the cutting deck (or implement),
shut off the engine, and do not set the parking brake.
4. Read all Warning, Cautions, and precautions listed at the beginning of this
section.
5. Clean the transmission area around the traction circuit hoses on the top of the
transmission (Figure
6. Disconnect the hydraulic hose from the transmission pump outlet fitting to
test the relief valve
Relief Valve to be Tested
Right side forward
Right side reverse
Left side forward
Left side reverse
7. Install a hydraulic tester (pressure and flow) in series with the pump outlet
and disconnected hose. Ensure that the tester flow arrow points from the
pump outlet port and toward the hose for the relief valve direction that is to be
tested. Ensure that the flow-control valve on the tester is fully open.
8. Start the engine and run it at low-idle speed (1,400 rpm). Check for
hydraulic-fluid leaks from the test connections and correct before continuing
the test.
Do not run the engine at full speed when performing this test using
Toro hydraulic tester (pressure and flow) (TOR214678). The traction
pump output at full engine speed can damage the hydraulic tester.
9. Use a phototac to measure the engine speed, move the throttle so that the
engine speed is 2,800 rpm (not full speed).
10. Completely close the flow control valve on the tester.
11. Keep the traction-control lever in the N
pump that is not tested.
12. Carefully monitor the tester pressure gauge, have an operator slowly push
the traction lever for the pump being tested (right side or left side) in the
direction being tested (forward or reverse) until the pressure gauge stabilizes
indicating that the relief valve has opened.
WARNING
4–11).
42). Determine which traction relief valve is to be tested.
(Figure 42):
IMPORTANT
EUTRAL
Page 4–41 Hydraulic System: Testing the Hydraulic System
position.
EUTRAL
Releasing Pressure
Pump Outlet
Port A
Port B
Port C
Port D
position for the transmission