2018 LEXUS RX450h Owners Manual

6017-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85UThe 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. 702)
■
Power control unit 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. 702)■
Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high qu ality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 ° F [-35 ° C])
Canada:
“Toyota Super Long Life Cool ant” is a mixture of 55% coolant and 45% deionized water.
(Minimum temperature: -44 ° F [-42 ° C])
For more details about coolant, contact your Lexus dealer.■
If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.Coolant 1
2
3
1
2
3

602 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UCheck the radiator and condenser an d clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer. WARNING ■
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps and radiator cap.
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.
Radiator and condenser WARNING ■
When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

6037-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85U■
Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■
Adding fluid
Make sure to check the fluid type and prepare the necessary item. ■
Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.Brake fluid
Fluid type FMVSS No.116 DOT 3 or SAE J1703 brake fluid
Items Clean funnel
WARNING ■
When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted surfaces.
If fluid gets on your hands or in your ey es, flush the affected area with clean water
immediately.
If you still experience di scomfort, see a doctor.
NOTICE ■
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 out or
when the fluid level in the accumulator is high.
If the reservoir needs frequent ref illing, there may be a serious problem.

604 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UIf none of the washer do not work or the
“Windshield Washer Fluid Low”
appears on the multi-information dis-
play, the washer tank may be empty.
Add washer fluid.Washer fluid
WARNING ■
When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as washer fluid
contains alcohol and may catch fire if spilled on the engine, etc.
NOTICE ■
Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle's painted surfaces, as well as damaging
the pump leading to problems of the washer fluid not spraying.■
Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.

6057-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85U 
RX450h
The 12-volt battery is located in the
left-hand side of luggage compart-
ment. 
RX450hL
The 12-volt battery is located in the
left-hand side of luggage compart-
ment.12-volt battery Location

606 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U 
RX450h
Lift the deck board and attach the hook. ( → P. 544)
Remove the cover after removing
the clips.
Press
Pull out 
RX450hL
Remove the deck board and side auxiliary box cover. ( → P. 545)
Remove the 12-volt battery cover.
Remove the deck side trim cover.Removing the 12-volt battery cover 1
2
1
2
1
2
3

6077-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85U 
RX450h
Make sure that the 12-volt battery terminals are not corroded and that there are
no loose connections, cracks, or loose clamps.
Terminals
Hold-down clamp 
RX450hL
Make sure that the 12-volt battery terminals are not corroded and that there are
no loose connections, cracks, or loose clamps.
Terminals
Hold-down clampExterior 1
2
1
2

608 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U 
RX450h
Install the 12-volt battery cover with the
clips.
Push up center position
Insert
Press 
RX450hL
Install the deck side trim cover.
Install the 12-volt battery cover.Installing the 12-volt battery cover 1
2
3
1
2