Toro ProLine H800 Service Manual page 119

Test Procedure (continued)
ProLine H800
19241SL Rev A
5. The steering circuit relief valve located in the steering control valve can be
tested with the pressure gauge installed in the same location as the steering
cylinder test (step 4) as follows:
A. Start the engine and run it at low-idle speed. Check for hydraulic-fluid
leaks from the test connections and correct before continuing the test.
B. Set the engine speed to approximately 2,000 rpm. Use a phototac to
check that the engine speed is correct.
Hold the steering wheel at full lock only long enough to get a
system pressure reading. Holding the steering wheel against the
stop for an extended period may damage the steering control
valve.
C. Monitor the pressure gauge carefully when turning the steering wheel for
a right hand turn (clockwise) and holding.
D. The system pressure should be approximately 120 to 125 bar (1,740 to
1812 psi) as the relief valve lifts.
E. Shut off the engine and record the test results.
6. If the specification is not met, replace the steering control valve; refer to
Steering Control Valve (page
7. After you complete the testing, shut off the engine, and then release hydraulic
system pressure; refer to
(page 5–5). Disconnect the pressure gauge, and connect removed hydraulic
hose to the steering cylinder.
8. Start the engine, check for hydraulic-fluid leaks, repair any leaks as required,
and fill the hydraulic tank with the correct quantity of new hydraulic fluid
before returning the machine to service.
IMPORTANT
5–112).
Releasing Pressure from the Hydraulic System
Page 5–51 Hydraulic System: Testing the Hydraulic System