MacDon 9352c SP - Manual (Page 98)

Form # 147459 Issue 11/06 Web Rev_01 96
MAINTENANCE/SERVICE
Traction Drive: Hydraulics
TRANSMISSION OIL PRESSURE
Warning light and buzzer in cab will be activated
when ignition switch is turned ON if transmission
oil pressure is below approximately 150 psi (1035
kPa). Do not drive the windrower until light and
buzzer go off. If light and buzzer stay on after
engine starts, or if they activate during operation,
shut engine off and check hydraulic oil level at
reservoir. If oil level is adequate, measure charge
pump pressure as described below.
CHARGE PUMP PRESSURE
The charge pump provides hydraulic power to the
traction drive. To check charge pump pressure:
1. Remove supercharge line at (A). This line runs
between “SC” port on manifold and
transmission pump. Place a tee capable of
accepting a pressure gauge in the line.
2. 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 tee inserted in Step 1.
3. Start engine and move throttle lever fully
forward. Pressure should be 270 to 290 psi
(1860 to 2000 kPa).
If pressure is not within this range, adjust relief
pressure as follows:
4. Shut off engine and remove key.
5. To adjust relief setting:
• Remove cap from relief valve (B) for access to
adjustment screw.
• Loosen jam nut at adjustment screw.
• Turn the adjustment screw in 1/4 turn
increments, clockwise to increase pressure,
counter-clockwise to decrease.
6. Repeat checking and adjustment until relief
pressure is correct, then tighten jam nut and
replace cap at (B).
IMPORTANT: If relief pressure does not increase
after adjusting the screw two or three times, check
relief valve as follows: Remove relief valve (B)
from flow control block. Check that no contaminant
is preventing the spring-loaded poppet from
properly seating against the valve body. Clean as
required, and reinstall valve. Reset adjustment
screw to original position before checking relief
pressure.
NOTE: For hydraulic schematics, see
“SCHEMATICS” section at back of this
book.
A
INSTALL TEE IN SUPERCHARGE LINE
B
CHARGE PUMP RELIEF VALVE