Page 14 6" & 8" Bear Cat Chipper Operators Manual
Handle pressurized hydraulic fluid carefully. Escaping
pressurized hydraulic fluid can have sufficient force to
penetrate your skin causing serious injury. This fluid may
also be hot enough to burn. Serious infection or reactions
can develop if proper medical treatment is not
Premium hydraulic fluids containing high quality rust,
oxidation, and foam inhibitors are required. These include
premium turbine oils, API CD engine oils per SAE J183,
M2C33F or G automatic transmission fluids meeting
Allison C-3 or Caterpillar TO-2, and certain specialty
agricultural tractor fluids.
5.11 PUMP COMPONENT LOCA-
TIONS (MODELS 72620 & 74824)
5.12 HYDROSTATIC PUMP START UP
PROCEDURE (MODELS 72620 &
5.10 HYDRAULIC FLUID (MODELS
72620 & 74824)
Service and Maintenance
A motor fitting may have to be loosened and oil bled to
remove air from the system (use same procedures as
Do not start engine unless pump is in neutral position on
Hydrostatic pressure controlled by the crossover relief
valve is factory set at 1750 PSI.
Follow this start-up procedure when starting a new
installation or when restarting an installation in which the
hydrostatic pump has been removed from the system.
1. Before starting the hydrostatic pump, make sure all
system components (reservoir, fittings, etc.) are clean.
2. Fill the reservoir with recommended hydraulic fluid, which
should be filtered before entering the reservoir.
3. The inlet line leading from the reservoir to the charge
pump must be filled before start-up. Loosen the fitting
on this inlet line until oil bleeds out.
4. Start the engine and run at the lowest possible RPM.
5. As air is purged from the unit, the oil level in the reser-
voir will drop and bubbles may appear in the fluid. Refill
the reservoir as necessary.
6. Run the unit and move the control arm in both direc-
tions for several minutes until any remaining air is purged
from the unit. Refill the reservoir as necessary.
7. Check to ensure feed roller stops when control arm is in
the neutral position. Adjust the cable clevis or anchor if
the feed roller doesn't stop.
8. Shut down the engine, check for and correct any fluid
leaks, and check the reservoir level. Add fluid if neces-
sary. The hydrostatic pump is now ready for operation.