Gravely Pro-Master PM 320 HD Owner's/Operator's Manual page 23

CHANGING HYDRAULIC OIL
Capacity: 5 qt. (4.73 L)
WARNING: HYDRAULIC FLUID
UNDER PRESSURE can
penetrate skin and cause severe
burns that can result in death or
serious injury. ALWAYS keep
body and hands away from pin
holes or nozzles which eject
hydraulic fluid under pressure.
ALWAYS use paper or cardboard
and not hands to search leaks.
Know that all hydraulic fluid
connections are tight and all
hydraulic hoses and lines are in
good condition BEFORE applying
pressure to the system. Foreign
fluid injected into the skin must be
surgically removed within a few
hours by a doctor familiar with this
form of injury or gangrene may
result.
1
1. Hydraulic Reservoir
2. Dipstick
3. Inlet Hose
4. Filter Housing
5. Outlet Hose
6. Hydraulic Filter
Figure 12
1. Park unit on a flat level surface, ensure
the engine is shut OFF, and the parking
brake is set.
2. Place a suitable container under inlet
hose.
3. Remove dipstick.
4. Remove inlet hose from filter housing.
5. Allow hydraulic oil to completely drain.
6. Install inlet hose on filter housing.
2
3
4
5
6
OF3404
GB - 23
7. Add 15W-50 synthetic oil as needed to
hydraulic reservoir. Do not overfill.
IMPORTANT: Ensure hydraulic oil is at
proper level before starting engine. Use Mobil
1 15W50 Extended Performance Synthetic
Oil.
8. Check hydraulic oil level.
NOTE: Dispose of used oil at a certified
recycling center.
CLUTCH ADJUSTMENT
If clutch fails to engage or disengage properly
or begins to make abnormal noise, check the
air gap adjustment at the three inspection
slots.
To check:
1. Stop engine, remove key and wait for all
hot parts to cool.
2. Measure the air gap between the
armature and the rotor.
Minimum: A .016" feeler gauge should
slide between armature and rotor with
slight contact.
Maximum: A .020" feeler gauge should
slide between armature and rotor with
slight contact.
3. Repeat for each inspection slot.
To adjust:
1. If necessary, loosen gap adjustment
nuts until a .016" feeler gauge fits
between armature and rotor.
2. Slide a .020" feeler gauge between
armature and rotor.
3. Tighten gap adjustment nut until there is
slight contact on feeler gauge.
4. Repeat steps 1 – 3 at each inspection
slot.
NOTE: Adjust air gap as evenly as possible.
5. Start unit, engage and disengage PTO.
6. Shut off unit.
7. Recheck air gap and adjust if needed.
4
3
1. Armature
2. Rotor
Figure 13
4
1
2
3. Inspection Slot
4. Gap Adjustment
Nut
OG1500