Page 156" & 8" Bear Cat Chipper Operators Manual
5.13 HYDRAULIC FEED MAINTE-
NANCE (72620 & 74824)
Service and Maintenance
Hydraulic systems contain fluid under high pressure.
Never check for leaks with your hands. Relieve pres-
sure before disconnecting any hydraulic lines.
Before servicing or repairing any of the hydrostatic feed
components (pump, motor, and/or relief valve), contact
your dealer or factory service department. Warranty on
these items may be void without prior authorization.
The hydrostatic pump normally does not require regular
fluid changes. The system filter should be changed at 250
hour or annual intervals. The fluid and filter should be
changed and system cleaned if the fluid becomes
contaminated with foreign matter (water, dirt, grease, etc.)
or if the fluid has been subjected to temperature levels
greater than the maximum recommended.
There is a greaseable bearing on each side of the main
jack shaft on the main hydraulic feed housing. Grease
2. Fill the reservoir with recommended hydraulic fluid.
(Note: The hydraulic fluid must be filtered before 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
at the pump on the inlet line until oil bleeds out.
4. Start the engine and run at the lowest possible RPM.
5. Loosen the motor fittings until oil bleeds out to remove
air from the system. Retighten fittings.
6. As air is expelled from the unit, the oil level in the reser-
voir drops down and bubbles may appear in the fluid.
Refill the reservoir as necessary.
7. Run the feed roller in both directions for several minutes
until any remaining air is completely expelled from the
unit. Refill the reservoir as necessary.
8. Shut down the engine, check and correct any fluid leaks.
check. Check the reservoir level and add fluid if neces-
sary. The hydrostatic pump is now ready for operation.
5.14 ADDING HYDRAULIC FLUID
Hydraulic fluid is used to drive the feed roller. The
hydraulic pump is attached to the motor (diesel models)
or connected to the motor with a belt (gasoline models).
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.
Below are the necessary startup procedures:
1. Before starting the hydrostatic pump, make sure all sys-
tem components (reservoir, fittings, etc.) are clean.