Jacobsen HR5111 Service And Repair Instructions page 161

SECTION 8Q. HYDRAULIC FIELD TEST PROCEDURES
LIFT AND LOWER CONTROL
(See Figure 8Q-4)
NOTE
Be sure engine is above 2000 rpm.
1. Isolate the circuit at fault by operating each han-
dle of the control valve separately.
NOTE
If all circuits are affected, perform an instrument
test, see Section 8R.
2. Lower all mowers, follow the procedure under the
circuit being affected.
Center
Remove hydraulic lines as shown in Figure 8Q-4.
Plug line and cap port.
Right Wing
Remove hydraulic lines as shown in Figure 8Q-4.
Plug line and cap port.
Left Wing
Remove hydraulic lines as shown in Figure 8Q-4.
Plug line and cap port.
3. Pull lift control lever, raising the mower(s) and hold.
•
If the engine labors slightly and a hissing sound
is heard, the valve is okay, proceed with Step 4.
•
If the engine is not affected or no hissing sound
is heard, valve may be at fault, proceed with an
instrument test, see Section 8R.
4. Reconnect hydraulic line removed in Step 2.
5. Pull lift control lever raising the mower(s) and hold.
6. Feel return line(s) of the cylinder(s). If the hydraulic
cylinder return line feels warm the cylinder may have
excessive internal leakage and should be rebuilt.
Figure 8Q-4. Lift and Lower Control
8Q-5
HYDRAULICS
8Q