Toyota 2004 Prius Owner's Manual page 285

If you can find no leak, have your Toyota
dealer test the cap pressure and check
for leaks in the cooling system.
CAUTION
To prevent burning yourself, do not
remove the radiator cap when the en-
gine is hot.
Coolant type selection
Use of improper coolants may damage
your cooling system.
Only use "Toyota Super Long Life Coolant"
or similar high quality ethylene glycol
based non−silicate, non−amine, non−nitrite,
and non−borate coolant with
hybrid organic acid technology. (Coolant
with long−life hybrid organic
technology is a combination
phosphates and organic acids.)
For the U.S.A.—"Toyota Super Long Life
Coolant" is a mixture of 50% coolant and
50% deionized water. This coolant pro-
vides protection down to about −35_C
(−31_F).
For Canada—"Toyota
Coolant" is a mixture of 55% coolant and
45% deionized water. This coolant pro-
vides protection down to about −42_C
(−44_F).
NOTICE
Do not use plain water alone.
long−life
acid
of low
Super Long Life
Toyota recommends "Toyota Super Long
Life Coolant", which has been tested to
ensure that it will not cause corrosion nor
result in malfunction of your coolant sys-
tem with proper usage. "Toyota Super
Long Life Coolant"
long−life hybrid organic acid technology
and has been specifically designed to
avoid cooling
Toyota vehicles.
Please contact your Toyota dealer for fur-
ther details.
is formulated with
system malfunction on
285