Bearings; Pressure Testing And Adjustment; After Service Startup And Checks - JLG sky trak mmv Service Manual

2.10

BEARINGS

2.10.1 Bearing Removal
1. NEVER remove bearings unless absolutely
necessary! Always use the recommended puller to
reduce the risk of bearing or related component
damage.
2. When bearings or bushings are removed, verify that
the bearing or bushing is free from discoloration,
nicks, scuffing, and signs of overheating. If in doubt,
replace the bearing or bushing.
2.10.2 Bearing Cleaning
Wear safety glasses. Clean bearings acceptable for ser-
vice in a suitable solvent. NEVER spin-dry a bearing with
compressed air; this can cause metal-to-metal contact
and bearing damage. Compressed air can also cause a
bearing to come apart. After cleaning a bearing, immerse
it in clean lubricating oil until needed.
2.10.3 Bearing Installation
1. Always install bearings carefully to help avoid
damaging their delicate surfaces.
2. Install bearings using one of the following methods:
• PRESS FIT for installation on rotating parts such
as shafts and gears;
• PUSH FIT into static locations such as reduction
gear housings.
3. Always install the bearing into the rotating part first
whenever possible.
4. Use a press or the proper installation tools when
installing a bearing or bushing.
5. In the absence of a press or proper installation tools,
carefully heat the casing and/or bearing in hot oil to
assist in the installation.
Model MMV Rev. 12/04
General Information, Specifications and Maintenance
2.11
Prior to pressure testing or adjustment, verify that all hos-
es and tubes are in good condition and that all fittings are
tight.
Use pressure gauges with the proper ranges and ratings
to measure the specified pressures.
Use correct test procedures to help prevent personal in-
jury, damage to the system or test equipment.
Verify that the hydraulic oil is at proper operating temper-
ature, 80-120° F (27-49° C), before adjusting the pres-
sure reducing valve, or relief valves. If necessary,
operate the vehicle to raise the oil temperature. In the ab-
sence of a temperature gauge, the oil temperature can be
checked by placing a hand against the side or the bottom
of the reservoir; if the tank is too hot to keep the hand in
contact with it, the oil temperature should be within the
proper range.
2.12
2.12.1
Note: Refer to the Owners/Operators Manual for engine
cold-start procedures.
1. Check fluid levels.
2. Connect the negative (-) battery cable to the battery
(if it is disconnected).
3. Start and idle engine. Check for leaks from hydraulic
components, engine, axles, transmission, brakes
and reservoirs or tanks. Check the levels of all fluids
and lubricants.
4. Purge the hydraulic system of air by operating all
vehicle functions through their entire range of motion
several times.
5. Check for proper operation of all components.
6. Retract all cylinders fully. Turn the engine OFF and
check the hydraulic reservoir level. Recheck the level
when the hydraulic oil is cold.
7. Replace the hydraulic filter if required.
PRESSURE TESTING AND
ADJUSTMENT
AFTER SERVICE STARTUP AND
CHECKS
After Service Startup
2.25