2017 Lexus GS300h coolant reservoir

4006-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
WARNING
The engine compartment contains many mech anisms and fluids that may move suddenly,
become hot, or become electrically energize d. To avoid death or serious injury, observe
the following precautions.
■When working on the engine compartment
●Make sure that the “POWER ON” on the multi-information display and the
“READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, power co ntrol unit, radiator, exhaust manifold, etc.
right after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily, such as paper and rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flamma-
ble.
●Take care because brake fluid can harm your hands or eyes and damage painted sur-
faces. If fluid gets on your hands or in your eyes, flush t he affected area with clean
water immediately. If you still experience discomfort, consult a doctor.
■When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fans may automatically start to
run if the air conditioning is on and/or the coolant temperature is high. ( P. 411)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting in
your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear due to dirt
in the air.
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear or when
the fluid level in the accumulator is high.
If the reservoir needs frequent refillin g, it may indicate a serious problem.

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6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Engine compartment
GS450h
■12-volt battery P. 412
Engine oil level dipstick
( P. 406)
Engine coolant reservoir ( P. 409)
Engine oil filler cap ( P. 407)
Power control unit coolant
reservoir ( P. 409) Fuse box (
P. 437)
Washer fluid tank ( P. 411)
Electric cooling fans
Condenser ( P. 411)
Radiator ( P. 411)1
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4046-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
GS300h
■12-volt battery P. 412
Power control unit coolant
reservoir ( P. 409)
Engine oil level dipstick ( P. 406)
Engine oil filler cap ( P. 407)
Engine coolant reservoir ( P. 409) Fuse box (
P. 437)
Washer fluid tank ( P. 411)
Electric cooling fans
Condenser ( P. 411)
Radiator ( P. 411)1
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6-3. Do-it-yourself maintenance
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Maintenance and care
GS450h_300h_OM_OM30F92E_(EE) The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” lin e, add coolant up to the “FULL” line.
(  P. 535)
■Power control unit coolant reservoir
Coolant
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GS450hGS300h
GS450hGS300h
Reservoir cap
“FULL” line
“LOW” line Reservoir cap
“F” line
“L” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”line. ( P. 535) If the level is on
or below the “L” line,
add coolant up to the “F” line. (  P. 535)
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4106-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -35 C [-31 F])
For more details about coolant, contact an y authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/p ower control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have any authorized Lexus retailer or Lexus authorized repairer,
or any reliable repairer, test the cap an d check for leaks in the cooling system.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control un it coolant reservoir caps or the coolant
inlet cap. ( P. 540)
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water and
antifreeze must be used to provide proper lubrication, corrosion protection and cool-
ing. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.

5367-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE) The coolant level is satisfactory if it is between the “FULL” and “LOW” lines
on the reservoir.
Reservoir
“FULL”
“LOW”
Coolant inlet cap
Add coolant if necessary. ( P. 539)
Water can be used in an emergency if engine coolant is unavailable.
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5387-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE) The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/
“L” lines on the reservoir.
Reservoir
“FULL”/“F”
“LOW”/“L”
Add coolant if necessary.
Water can be used in an emergency if po wer control unit coolant is unavailable.
Start the hybrid system and check for the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact any authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
If the message is not displayed:
Have the vehicle inspected at the nearest any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
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5407-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
●If steam is seen coming from under the h ood, do not open the hood until the steam
has subsided. The engine compartment may be very hot.
●After the hybrid system has been turned off, check that the indi cator on the power
switch and the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automatically start, or
the cooling fan may suddenly operate even if the gasoline engine stops. Do not touch
or approach rotating parts such as the fan, which may lead to fingers or clothing
(especially a tie, a scarf or a muffler) getting caught, resulting in serious injury.
●Do not loosen the coolant inlet cap or the
coolant reservoir caps while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.GS450h
GS300h