Hydraulics; 4-8.1 Line And Fitting Replacement; 4-8.2 Hydraulic Pump, Motor, And Reservoir Assembly - Big Joe PPT 45 Series Operation, Maintenance, Repair Parts

4-8. HYDRAULICS.

4-8.1 Line and Fitting Replacement.

DANGER
• Hydraulic oil under pressure can penetrate
the skin. It is toxic and can damage tissue.
Always use a piece of wood or cardboard to
check for suspected hydraulic leaks. NEVER
USE YOUR HANDS.
medical attention from a medical provider
knowledgeable with hydraulic fluid injuries if
pressurized hydraulic fluid pierces the skin.
Failure to obtain prompt medical assistance
could result in gangrene or other serious
damage to tissue.
• When forks are raised, pressure exists in the
hydraulic system lines and fittings. To
ensure release of pressure, forks must be
fully lowered and the battery disconnected
before performing any maintenance on the
hydraulic system.
NOTE: Leaking hydraulic fittings may be repaired by
simply tightening the fittings. If this does not
repair the leak, the fittinìg or line must be
replaced.
1. Lower forks fully.
2. Disconnect battery (Section 4-7.1).
3. Remove motor compartment (service) cover.
IMPORTANT
Hydraulic oil can damage parts. Wipe off any oil
immediately. Provide a container under line or fitting,
before disconnecting.
PPT0104-901336
Obtain immediate
4. Refer to Figure 4-31 and remove leaking line (2) or
fitting and replace it with a new line or fitting.
5. Remove the vent plug and elbow (5 & 6, Figure 4-
31). Check level of hydraulic oil. Hydraulic oil must
be one inch below bottom of elbow (5). If required,
add hydraulic oil to bring to proper level. Use
hydraulic oil listed in Table 3-3.
6. Reinstall the vent plug (6).
7. Reconnect the battery and operate the lift lower
button to refill cylinder and lines with hydraulic oil.
8. Lower forks fully and disconnect battery.
9. Recheck hydraulic oil level, see Steps 5 and 6.
10. Install motor compartment (service) cover.
11. Reconnect the battery.
1 2
6 5
Figure 4-31. Hydraulic System
4-8.2 Hydraulic Pump, Motor, and Reservoir
Assembly.
The hydraulic pump, motor, and reservoir assembly
can be disassembled and repaired. The motor and
control valves can be repaired, however, a defective
pump must be replaced as a complete unit. Proceed as
follows to remove and disassemble the hydraulic
pump, motor, and reservoir assembly
3
4
I-7033
4-27