Toro Reelmaster 7000 Service Manual page 79

NOTE: Adjustable relief valve (RV) in the 4WD/2WD
control manifold reduces rear axle motor pressure
created in down hill, dynamic braking conditions to pre-
vent rear wheel lock up.
Procedure for Rear Traction Circuit Relief (RV) Pres-
sure Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately ten
(10) minutes. Make sure the hydraulic tank is full.
2. Park machine on a level surface with the cutting units
lowered and off. Make sure engine is off and the parking
brake is engaged.
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
3. Measure and record traction circuit pressure redu-
cing valve (PR) pressure (see Traction Circuit Pressure
Reducing Valve (PR) Pressure Test in this section).
4. Connect a 1000 PSI (70 bar) pressure gauge to test
fitting (port G) on rear side of 4WD/2WD control manifold
under front of machine (Figs. 34 and 35). This is the
same pressure gauge position as used to measure trac-
tion circuit pressure reducing valve (PR) pressure.
5. After installing pressure gauge, start engine and run
at low idle speed. Check for hydraulic leakage and cor-
rect before proceeding with test.
6. Move throttle to high idle speed (2850 RPM). Make
sure that mow speed limiter is in the mow (4WD) posi-
tion. Release parking brake.
7. Operate the machine in mow speed (4WD) with the
cutting units lowered. Drive down a slope in a forward di-
rection and decrease pressure on the traction pedal
while carefully monitoring the pressure gauge. Pressure
should increase until relief valve (RV) lifts.
8. Stop engine and record test results.
9. Relief (RV) pressure should be at least 100 PSI (7
bar) higher than the traction circuit pressure redu-
cing valve (PR) pressure and also be between 520
and 570 PSI (36 to 39 bar) (e.g. if the pressure reducing
valve (PR) pressure is 450 PSI (31 bar), relief (RV) pres-
sure should be from 550 to 570 PSI (38 to 39 bar)).
Reelmaster 7000
NOTE: Rear traction circuit relief (RV) pressure should
be at least 100 PSI (7 bar) higher than traction circuit re-
ducing (PR) pressure. If the difference in these pres-
sures is less than 100 PSI (7 bar), reverse traction
performance may be affected.
10.If specification is not met, clean or adjust relief valve
(RV) which is located on the left side of the 4WD/2WD
control manifold in the RV port (Fig. 34) (see Adjust Con-
trol Manifold Relief Valves in the Adjustments section of
this chapter for valve adjustment procedure). Recheck
relief (RV) pressure after adjustment.
11. When testing is completed, disconnect pressure
gauge from test port. Install dust cap to test port fitting.
RIGHT
FRONT
1. 4WD/2WD manifold
1. 4WD/2WD manifold
Page 4 - - 45
Rev. A
1
Figure 34
2. Relief valve (RV)
1
2
Figure 35
2. Test fitting (port G)
Hydraulic System
2