Service Manual

Introduction General Description
The purpose of this manual is to provide information
useful
in servicing the Bantam Duty Hydrostatic Pumps.
This manual includes unit and component description,
troubleshooting, minor repair procedures, and major
repair procedures.
A pump normally will not require servicing during the lie
of the vehicle or machine in which
it is installed. Should
servicing be required, some repairscan beaccomplished
without removing the unit from
its installed location,
provided that the unit is accessible and can be thoroughly
cleaned before beginning any procedures. Since dirt or
contamination is the greatest enemy of any hydraulic
equipment, the greatest possible cleanliness is neces-
sary.
BDP-10L Pump
The BDP pumps can be combined with motors and other
remotely
located units. When used in this manner, these
units provide an infinitely variable speed range between
zero and maximum in both forward and reverse modes of
operation.
The BDP-1
0L is a variable displacement pump designed
for vehicle applications where up to
six horsepower is
required for the propel function, or for auxiliary functions
where the system pressure requirements and design life
can be met within the pump rating. This variable
displace-
ment pump has a maximum displacement of 0.61 in³/rev
(10 cc/rev).
Pumps are of the
axial piston design, utilizing spherical
nosed pistons. A compression spring, located inside
each piston, holds the
nose of the piston against a thrust
bearing
race.
The variable displacement pump features a cradle
swashplate with a direct-proportional displacement con-
trol. Reversing the direction of tilt of the swashplate
reverses the flow of oil from the pump and thus reverses
the direction of the motor output rotation.
A fixed displacement gerotor charge pump is provided in
the BDP-10L units. Oil from an external reservoir and
fitter is pumped into the closed loop by a charge pump.
Fluid not required to replenish theclosed loop flows either
into the pump housing through a cooling orifice, or back
to the charge pump inlet through the charge pressure
relief valve.
Charge check valves are included in the pump end cap
to control the makeup oil
flow for the system.
valve is utilized in the pumps to
for short distances at
the engine.
BDP Service Manual