Toyota Prius Owners Manual
Checking the coolant level
Engine coolant reservoir
Inverter coolant reservoir
The coolant heat storage tank reacheshigh temperature inside. It is dangerousif hot coolant is discharged whenreplacing. For replacement of thecoolant, contact your Toyota dealer.
Look at the see−through coolant reservoirwhen the hybrid system is cold.The coolant level is satisfactory if it isbetween the “FULL” and “LOW” lineson the reservoir. If the level is low, addthe coolant. (For the coolant type, see“Coolant type selection” described below.)
The coolant level in the reservoir will varywith hybrid system temperature. However,if the level is on or below the “LOW” line,add coolant. Bring the level up to the“FULL” line.
If the coolant level drops within a shorttime after replenishing, there may be aleak in the system. Visually check theradiator, hoses, radiator cap and draincock and water pump.
If you can find no leak, have your Toyotadealer test the cap pressure and checkfor leaks in the cooling system.
If the fluid level in the inverter coolantreservoir is low, there may be a problemwith the cooling system. Have the vehiclechecked by your Toyota dealer.
To prevent burning yourself, do notremove the radiator cap when the engineis hot.
Coolant type selection
Use of improper coolants may damageyour cooling system.
Only use “Toyota Super Long Life Coolant”or similar high quality ethylene glycolbased non−silicate, non−amine, non−nitrite,and non−borate coolant with long−lifehybrid organic acid technology. (Coolantwith long−life hybrid organic acidtechnology is a combination of lowphosphates and organic acids.)
For the U.S.A.—“Toyota Super Long LifeCoolant” is a mixture of 50% coolant and50% deionized water. This coolant providesprotection down to about −35 C(−31 F).
For Canada—“Toyota Super Long LifeCoolant” is a mixture of 55% coolant and45% deionized water. This coolant providesprotection down to about −42 C(−44 F).
Do not use plain water alone.
Toyota recommends “Toyota Super LongLife Coolant”, which has been tested toensure that it will not cause corrosion norresult in malfunction of your coolant systemwith proper usage. “Toyota SuperLong Life Coolant” is formulated withlong−life hybrid organic acid technologyand has been specifically designed toavoid cooling system malfunction onToyota vehicles.
Please contact your Toyota dealer for furtherdetails.