Toro Groundsmaster 4500-D Series Service Manual page 160

Procedure for Rear Traction Circuit Relief Valve (RV) Pressure Test (continued)
Hydraulic System: Testing
5. Start engine and increase engine speed to high idle speed. Make sure
that Auto/LOW mode switch is in the LOW (mow) position and release the
parking brake.
6. Measure and record reverse traction circuit reducing valve (PR) pressure
(see Reverse Traction Circuit Reducing Valve (PR) Pressure (Using Pressure
Gauge) (page 5–53)).
7. Operate the machine in LOW speed (mow) with the cutting decks lowered.
Drive down a slope in a forward direction, decrease pressure on the traction
pedal and monitor the pressure gauge. Pressure should increase until the
rear traction circuit relief valve (RV) lifts.
GAUGE READING TO BE approximately 38 bar (550 PSI) and at least 7
bar (100 PSI) higher than the traction circuit pressure reducing valve (PR)
pressure (e.g. if the pressure reducing valve (PR) pressure is 31 bar (450
PSI), relief (RV) pressure should be at least 38 bar (550 PSI) but not much
higher).
8. Stop engine and record test results.
g308370
1. Rear traction manifold
2. #6 zero leak plug
9. The rear traction circuit relief valve (RV) is located on the bottom of the rear
traction manifold (Figure
(RV) (see Adjust Control Manifold Relief Valves (page
10. When testing is completed, disconnect pressure gauge from the installed
diagnostic fitting. Remove diagnostic fitting from manifold and install removed
plug into manifold. Torque plug to 34 N·m (25 ft-lb).
Figure 69
3. Relief (RV) valve
4. Reducing (PR) valve
69). If test pressure is incorrect, adjust relief valve
Page 5–58
5–86)).
Groundsmaster ® 4500-D/4700-D
19245SL Rev A