2013 Lexus GS300h coolant reservoir

733 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
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 automat-
ically start to run if the air conditioning is on and/or the coolant temperature
is high.
(P. 747)
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 refilling, it may indicate a serious problem.

7386-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
Engine compartment
GS300h
12-volt battery
P. 7 4 9
Power control unit coolant
reservoir (P. 745)
Engine oil level dipstick
(P. 741)
Engine oil filler cap (P.
742)
Engine coolant reservoir
(P. 744)Fuse box (P. 782)
Washer fluid tank (P. 748)
Electric cooling fans
Condenser (P. 747)
Radiator (P. 747)1
2
3
4
5
6
7
8
9

739 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30D53E_(EE)
GS450h
12-volt battery
P. 7 4 9
Engine oil level dipstick
(P. 741)
Engine coolant reservoir
(P. 744)
Engine oil filler cap (P.
742)
Power control unit coolant
reservoir (P. 745)Fuse box (P. 782)
Washer fluid tank (P. 748)
Electric cooling fans
Condenser (P. 747)
Radiator (P. 747)1
2
3
4
5
6
7
8
9

7446-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
The coolant level is satisfactory if it is between the “FULL” and
“LOW” 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” line, add coolant up to the
“FULL” line. (P. 915)
Coolant
GS300hGS450h
1
2
3

745 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30D53E_(EE)
Power control unit coolant reservoir
GS300hGS450h
Reservoir cap
“F” line
“L” lineReservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“L” line, add coolant up to the
“F” line. (P. 9 1 5 )If the level is on or below the
“LOW” line, add coolant up to
the “FULL” line. (P. 915)
1
2
3
1
2
3

7466-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality eth-
ylene glycol based non-silicate, non-amine, non-nitrite, and non-borate cool-
ant with long-life hybrid organic acid technology.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50%
deionized water. (Minimum temperature: -35C [-31F])
For more details about coolant, contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reser-
voir caps, drain cock and water pump.
If you cannot find a leak, have any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional, test the cap and check for
leaks in the cooling system.
CAUTION
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or the
coolant inlet cap. (P. 9 2 1 )
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 cooling. 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.

9187-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
After the hybrid system has cooled down sufficiently, inspect
the hoses and cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immediately contact your Lexus
dealer.
The coolant level is satisfactory if it is between the “FULL”
and “LOW” lines on the reservoir.
Reservoir
“FULL”
“LOW”
Coolant inlet cap
3
1
2
GS300hGS450h
4
1
2
3
4
GS300hGS450h

9207-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
If “Hybrid System Overheat” is shown on the multi-information
display
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled down, inspect the hoses
and radiator core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immediately contact your Lexus
dealer.
The coolant level is satisfactory if it is between the “F”/
“FULL” and “L”/“LOW” lines on the reservoir.
Reservoir
“F”/“FULL”
“L”/“LOW”
1
2
3
1
2
GS300hGS450h
4
1
2
3
GS300hGS450h