Kohler Aegis LH775 Service Manual page 56

Cooling System
coolant level below ADD mark.
Add coolant to overfl ow reservoir as required, which
is a 50/50 mixture of ethylene glycol and water
(distilled or deionized water is recommended).
Drain Cooling System
Radiator Drain Plug Details
A Radiator Drain Plug
1. Ensure engine is cool. When radiator is cool to
touch, slowly loosen radiator cap to fi rst stop and
allow any pressure to bleed off. Then loosen it fully
and remove it.
Loosen/remove radiator drain plug and allow coolant
to drain.
2. If equipped, remove coolant drain plugs located on
each side of engine block. Drain coolant into a
suitable container. After coolant has drained
completely, apply pipe sealant with Tefl on
PST 592™ or equivalent), to threads and reinstall
®
plugs. Torque plugs to 36.7 N·m (325 in. lb.).
3. Remove overfl ow hose from reservoir. Unhook
inboard retainer and slide reservoir out of supports.
Pour out contents and wash or clean as required.
Dispose of all old coolant in accordance with local
ordinances.
4. Reinstall reservoir cap. Do not kink/pinch hose.
5. Flush cooling system.
Flushing Cooling System
NOTE: To prevent engine damage, do not pour water
into a hot engine. Do not operate engine without
coolant.
With system properly drained:
1. Fill cooling system with clean water and a cooling
system cleaner recommended for aluminum
engines. Follow directions on container.
2. Reinstall and tighten radiator cap.
3. Start and run engine for fi ve minutes, or until it
reaches operating temperature. Stop engine and
allow it to cool.
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4. Drain cooling system.
5. Fill cooling system.
Filling Cooling System
NOTE: To prevent engine damage, do not use
antifreeze mixture greater than 70% ethylene
glycol in cooling system. Do not use antifreeze
with stop-leak additive(s) or mix/add other
additives to cooling system. Use only ethylene
glycol antifreeze.
Cooling system capacity is approximately 2 liters
(2.18 qt.).
1. Check condition of cooling system hoses, clamps,
and associated components. Replace as required.
2. Fill with 2.0 L (2.1 U.S. qt.) equal parts of ethylene
glycol (anti-freeze) and water only. Distilled or
deionized water is recommended, especially in
areas where water contains a high mineral content.
Propylene glycol based anti-freeze is not
recommended.
3. Fill radiator with coolant mixture. Allow coolant to
drain into lower areas. Fill overfl ow reservoir to a
level between FULL and ADD marks. Reinstall
radiator and reservoir caps.
4. Start and run engine for fi ve minutes. Stop engine
and allow to cool.
5. Recheck coolant level in reservoir. Coolant level
should be between FULL and ADD marks. Add
coolant to reservoir if required.
Inspection
Cooling Fan Assembly, Belt, and Drive Pulleys
Cooling fan assembly, used to draw air through radiator,
is attached to a hub and pulley assembly with sealed
ball bearings. This assembly is belt driven off fl ywheel,
via a lower split pulley, and requires very little service or
maintenance. DO NOT operate engine without fan and
properly functioning cooling system or engine damage
will occur.
1. Inspect fan for any cracks, damaged/missing fan
blades, and secure mounting.
2. Bearings in hub of pulley should rotate smoothly,
without roughness, binding, or play/wobble.
3. V-groove of each pulley (upper and lower) should
not be bent, nicked, or damaged. Pulley mounting
areas and lower pulley shims should be free of any
cracks or elongation.
4. Drive belt is designed and constructed for this
system. Do not use a substitute belt. Check overall
condition and replace belt if cracked, damaged, or
proper tension cannot be established by
repositioning of lower pulley shims. Use only Kohler
Part No. 66 203 02-S belt if replacement is
necessary.
See a Kohler authorized dealer for any necessary
service.
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