JLG G12-55A Service Manual - Manual (Page 107)

7-9 G10-55A, G12-55A
Engine
b. Thermostat Installation
1. Install the engine thermostat, thermostat gasket and
thermostat housing. Secure with the two capscrews
and torque as required.
2. Connect the engine water temperature sender if
connected to the thermostat housing.
3. Properly connect the battery.
4. Open the radiator cap, and fill the radiator
completely with coolant. Replace and tighten the
radiator cap. Add coolant to the overflow bottle until
the bottle is 1/4 to 1/2 full. This overfilling will
compensate for any air trapped in the cooling
system.
5. Run the engine to operating temperature. Visually
check for leaks with the engine running. Check the
coolant level in the overflow bottle and fill, or drain,
as necessary.
6. Close and secure the engine cover.
7. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
7.4.3 Radiator/Oil Cooler and Replacement
Before considering radiator or oil cooler replacement for
other than obvious damage, conduct a cooling system
pressure test check the coolant specific gravity, coolant
level, fan belt tension and dash panel temperature
indicator.
• If the engine runs hot, check the temperature of
the upper radiator hose.
• If the hose is not hot, the thermostat may be
stuck in the closed position.
• If the engine has overheated, performance may
suffer, indicating other damage including a leaking
cylinder head gasket, cracked cylinder head or
block, and/or other internal engine damage.
a. Radiator/Oil Cooler Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, lower the boom,
place the travel select lever in the (N) NEUTRAL
position, engage the parking brake, and shut the
engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and steering wheel, stating that the machine
should not be operated.
3. Open the engine cover. Allow the system fluids to
cool.
4. Properly disconnect the battery.
5. Slowly turn the radiator cap to the first stop and allow
any pressure to escape. Remove the radiator cap.
6. Place a suitable container beneath the radiator
drain.
7. Place a funnel at the base of the radiator to channel
the drained coolant into a container. Loosen the
drain cock and slowly remove to allow the coolant to
drain. Transfer the coolant into a properly labeled
container. Dispose of properly if coolant needs to be
replaced. Tighten the radiator drain cock.
8. Label, disconnect and cap the hoses attached to the
coolant recovery tank. Remove the coolant recovery
tank.
9. Loosen the clamps on the hoses/tubes (4) attached
to the intercooler. Work the hoses off the intercooler.
Position the hoses out of the way to allow radiator
removal, or remove the hoses from the engine.
Inspect the hoses, and replace if necessary.
10. Loosen the clamps on the hoses (5) attached to the
radiator. Work the hoses off the radiator. Position the
hoses out of the way to allow radiator removal, or
remove the hoses/tubes from the engine. Inspect the
hoses, and replace if necessary.
11. Loosen and remove the hoses (6) attached to the oil
cooler. Plug and/or cap the hoses to prevent dirt and
debris from entering the hydraulic system. Position
the hoses out of the way to allow radiator removal, or
remove the hoses from the engine. Inspect the
hoses, and replace if necessary.
MY4530
CUMMINS RADIATOR ASSSEMBLY
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