Toro GroundsmasterR 4300-D Service Manual page 89

The steering relief valve (R10) pressure test should be
performed to make sure that the steering circuit relief
pressure is correct.
Procedure for Steering Relief Valve Pressure Test:
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes.
2. Park machine on a level surface with the cutting
decks lowered and PTO switch off. Make sure engine is
off. Apply the parking brake.
3. Read Precautions For Hydraulic Testing in this sec-
tion.
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
4. Thoroughly clean the area around the hydraulic hose
at the rod end of the steering cylinder (Fig. 60).
5. Remove hydraulic hose from the fitting on the rod
end of the steering cylinder.
6. Install a tee fitting between the disconnected hydrau-
lic hose and the steering cylinder fitting. Install a 5000
PSI (350 bar) pressure gauge to the tee fitting.
7. After installing pressure gauge, start engine and run
at idle speed. Check for any hydraulic leakage from test
connections and correct before proceeding with test.
8. Move throttle to full speed (3200 RPM).
IMPORTANT: Hold 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.
9. Watch pressure gauge carefully while turning the
steering wheel for a left hand turn (counter--clockwise)
and holding.
10.System pressure should be approximately 1000 PSI
(70 bar) as the relief valve lifts. Return steering wheel to
the neutral position.
11. Shut off engine. Record test results.
Groundsmaster 4300--D
12.If specification is not met, inspect steering control
valve (see Steering Control Valve Service in the Service
and Repairs section of this chapter).
13.After testing is completed, make sure that engine is
stopped, then relieve hydraulic system pressure (see
Relieving Hydraulic System Pressure in the General In-
formation section of this chapter). Remove tee fitting
and pressure gauge from hydraulic hose and steering
cylinder. Connect hydraulic hose to steering cylinder fit-
ting.
2
1. Steering cylinder
Page 4 - - 57
1
Figure 60
2. Rod end fitting
Hydraulic System