caution - Toro
caution - Toro
caution - Toro
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Procedure for Lift/Lower Circuit Relief Pressure<br />
Test<br />
NOTE: Before attempting to check or adjust lift pressure,<br />
make sure that counterbalance pressure is correctly<br />
adjusted.<br />
1. Make sure hydraulic oil is at normal operating temperature<br />
by operating the machine for approximately 10<br />
minutes. Make sure the hydraulic tank is full.<br />
3<br />
2<br />
2. Park machine on a level surface with the cutting deck<br />
lowered and off. Make sure engine is off and the parking<br />
brake is engaged.<br />
4<br />
1<br />
CAUTION<br />
Prevent personal injury and/or damage to equipment.<br />
Read all WARNINGS, CAUTIONS and Pre<strong>caution</strong>s<br />
for Hydraulic Testing at the beginning<br />
of this section.<br />
3. Raise seat to gain access to hydraulic test fitting.<br />
Connect a 5,000 PSI (345 bar) gauge to lift circuit test<br />
port (Fig. 41). Route gauge hose to allow seat to be safely<br />
lowered.<br />
4. After installing pressure gauge, start engine and run<br />
at idle speed. Check for hydraulic leakage and correct<br />
before proceeding with test.<br />
5. Sit on the seat and operate the engine at full speed<br />
(2870 RPM).<br />
6. While sitting on the seat, pull lift lever back to raise<br />
the cutting deck. Momentarily hold the lever with the lift<br />
cylinder fully retracted (deck fully raised) while looking<br />
at the gauge.<br />
GAUGE READING TO BE 2500 to 2550 PSI (173 to<br />
175 bar).<br />
7. Stop the engine and record test results.<br />
8. If pressure is too high, adjust relief valve in lift control<br />
valve by rotating counterclockwise (Figure 42). If pressure<br />
is too low, check for restriction in pump intake line.<br />
Check the lift cylinder for internal leakage. If cylinder is<br />
not leaking, adjust the relief valve by rotating clockwise.<br />
If pressure is still too low, pump or lift cylinder(s) should<br />
be suspected of wear, damage or inefficiency.<br />
9. When testing is completed, disconnect pressure<br />
gauge from test port.<br />
1. Fan drive manifold<br />
2. Lift circuit test port<br />
1. Control valve assembly<br />
2. Relief valve assembly<br />
3. Washers<br />
Figure 41<br />
Figure 42<br />
3. Lift control valve<br />
4. Relief valve<br />
4. Spring<br />
5. Poppet<br />
2<br />
3<br />
4<br />
5<br />
1<br />
Hydraulic<br />
System<br />
Groundsmaster 4100--D<br />
Page 4 - 53<br />
Hydraulic System
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