MacDon M150 SP - Manual (Page 201)

MAINTENANCE AND SERVICING
Form 169017 / 169087 / 169095
199
Revision C
7.12.6 TRACTION DRIVE HYDRAULICS
7.12.6.1 Transmission Oil Pressure
The windrower transmission consists of two
variable displacement axial piston hydraulic
pumps - one for each drive wheel.
The pumps are driven through a gearbox from the
engine. Each pump requires charge flow to make
up for internal leakage, maintain positive pressure
in the main circuit, provide flow for cooling and
replace any leakage losses from external valving
or auxiliary systems.
The charge pressure is monitored, and if it drops
below 250 psi (1725 kPa), the CDM sounds a tone
and displays a flashing warning. Refer to Section
5.18.4 Cab Display Module (CDM) Warnings and
Alarms.
IMPORTANT
Rated charge pressure must be maintained
under all conditions of operation to prevent
damage to the transmission.
If the TRANS OIL PRESSURE warning is
displayed, shutdown the engine, and proceed as
follows:
a. Check the hydraulic fluid level in the tank. Refer
to Section 7.12.1 Oil Level.
b. Check the hoses and lines for leakage.
c. Check the charge pressure relief valve. Refer to
following section.
d. If charge pressure still cannot be maintained, do
not operate the windrower. Contact your
Windrower Dealer.
7.12.6.2 Charge Pump Pressure
Incorrect charge pressure settings may result in
the inability to build required system pressure,
and/or inadequate loop flushing flows. Correct
charge pressure must be maintained under all
conditions to maintain pump control performance
and to operate the brake release
Check and adjust charge pump pressure as
follows:
DANGER
Stop engine and remove key from ignition
before leaving Operator’s seat for any reason.
A child or even a pet could engage an idling
machine.
a. Open engine compartment hood fully.
b. Remove cap (A) at fitting.
c. Attach a 0 - 600 psi (4000 kPa) pressure gauge to
a hose that is long enough to allow pressure
gauge to be read from the Operator’s seat. Attach
hose to the fitting.
d. Start engine and leave at idle. Pressure should be
330 to 360 psi (2275 to 2482) kPa) with the
hydraulic oil at 100°F. (40°C) minimum.
e. If pressure is not within this range, adjust relief
pressure as follows:
1. Shut off engine, and remove key.
2. Remove cap (C) from relief valve (B) for
access to adjustment screw.
(continued next page)
A
C
B