2001 TOYOTA PRIUS radiator cap

PP2FH±02
± PREPARATIONCOOLING
PP±13
2001 PRIUS (RM778U)
EQUIPMENT
Belt tension gauge
HeaterThermostat
Radiator cap tester
ThermometerThermostat
Torque wrench
Vernier calipers

SS176±03
SS±14
± SERVICE SPECIFICATIONSCOOLING
136 Author: Date:
2001 PRIUS (RM778U)
COOLING
SERVICE DATA
Drive beltTension (Reference) New belt
Used belt110 ± 11 lbf
67 ± 10 lbf
ThermostatValve opening temperature
at 90°C (199°F)80.0 ± 84.0°C (176 ± 183°F)
8.5 mm (0.345 in.) or more
Radiator capRelief valve opening pressure STD
Minimum74 ± 103 kPa (0.75 ± 1.05 kgf/cm2, 10.7 ± 14.9 psi)
79 kPa (0.8kgf/cm2, 11.5 psi)
Electric
cooling fanAmperage STD9.2 ± 11.0 A

A12943
1
2973
4
3
368
5
A11228
1
23
45
67
8
9
10
A12944
± ENGINE MECHANICALCYLINDER HEAD
EM±31
2001 PRIUS (RM778U)

Do not disassembly the valve timing controller as-
sembly.
25. REMOVE CAMSHAFTS
Uniformly loosen and remove the 19 bearing cap bolts, in sever-
al passes, in the sequence shown, and remove the 9 bearing
caps, intake and exhaust camshafts.
26. REMOVE CYLINDER HEAD
(a) Disconnect the upper radiator hose from the water hose
union
(b) Disconnect the heater water hose from the water hose
union
(c) Using a 8 mm bi±hexagon wrench, uniformly loosen and
remove the 10 cylinder head bolts, in several passes, in
the sequence shown. Remove the 10 cylinder head bolts
and plate washers.
NOTICE:
Head warpage or cracking could result from removing
bolts in an incorrect order.
(d) Remove the bolt holding the water bypass pipe to the cyl-
inder head.
(e) Lift the cylinder head from the dowels on the cylinder
block and replace the cylinder head on wooden blocks on
a bench.
HINT:
If the cylinder head is difficult to lift off, pry between the cylinder
head and cylinder block with a screwdriver.
NOTICE:
Be careful not to damage the contact surfaces of the cylin-
der head and cylinder block.

A12945
No.1 Cam Lobe
A12946
A12943
9
9
96
5
2
1
4
3
8
7 EM±46
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
(g) Connect the upper radiator hose to the water hose
unions.
(h) Connect the heater hose to the water hose unions.
3. INSTALL CAMSHAFTS
(a) Place the 2 camshafts on the cylinder head with the No.1
cam lobes facing as shown the illustration.
(b) Install the bearing caps in their proper locations.
HINT:
No. 2 camshaft bearing cap has a number and front mark.
(c) Apply a light coat of engine oil on the threads and under
the heads of the bearing cap bolts.
(d) Install and uniformly tighten the 19 bearing cap bolts.
After tightening the No.1 camshaft bearing cap, tighten
then in several passes, in the sequence shown.
Torque:
No. 1 23 N´m (235 kgf´cm, 17 ft´lbf)
No. 2 12.7 N´m (130 kgf´cm, 10 ft´lbf)
4. INSTALL VALVE TIMING CONTROLLER ASSEMBLY
AND CAMSHAFT TIMING SPROCKET
(a) Apply engine oil in the rage from the tip of the intake cam-
shaft to 16 mm from that tip.
(b) Except leaded gasoline spec:
Align the timing mark on the valve timing controller as-
sembly with the knock pin, and install the value timing
controller assembly to the camshaft.
NOTICE:
Do not push valve timing controller assembly to the cam-
shaft forcibly when installing it.
(c) Align the knock pin hole in the camshaft timing sprocket
with the knock pin of the camshaft, and install the sprock-
et to the camshaft.

CO04E±09
B11768
Engine
Drain Plug
Radiator
Drain Plug
CO±2
± COOLINGCOOLANT
2001 PRIUS (RM778U)
REPLACEMENT
1. DRAIN ENGINE COOLANT
(a) Remove the radiator cap.
CAUTION:
To avoid the danger of being burned, do not remove the ra-
diator cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
(b) Loosen the radiator drain plug (on the right side of the ra-
diator lower tank) and engine drain plug on the engine
coolant drain union (on the right front of the cylinder
block), and drain the coolant.
(c) Close the drain plugs.
Torque: 12.7 N´m (130 kgf´cm, 9 ft´lbf) for engine
2. FILL ENGINE COOLANT
(a) Slowly fill the system with coolant.

Use of improper coolants may damage the engine
cooling system.

Use ºToyota Long Life Coolantº or equivalent and
mix it with plain water according to the manufacture
directions.

Use of the coolant which includes more than 50%
[freezing protection down to ±35°C (±31°F)] or 60%
[freezing protection down to ±50°C (±58°F)] of eth-
ylene±glycol is recommended, but not more than
70%.
NOTICE:

Do not use an alcohol type coolant or plain water
alone.

The coolant should be mixed with plain water (prefer-
ably demineralized water or distilled water).
Capacity: 4.9 litters (5.2 US qts, 4.3 lmp qts)
(b) Install the radiator cap and start the engine. After repeat-
edly idling and racing the engine several times for approx.
2 minutes, stop the engine.
(c) Remove the radiator cap and fill the radiator with engine
coolant until it reaches the rim of the radiator filler.
If the engine coolant level of the radiator drops when grasping
the radiator inlet hose and outlet hose several times by hand,
add more coolant.
(d) Install the radiator cap. Activate inspection mode (See
page IN±10). Warm it up until the radiator fan starts to turn
with the engine speed at less than 2,500 rpm.
NOTICE:
Stop the engine immediately after the radiator fan starts to
turn.
(e) Stop the engine and cool it down.
NOTICE:
Cool down the engine until its temperature becomes below
50°C (122 °F).

± COOLINGCOOLANT
CO±3
2001 PRIUS (RM778U)
(f) Remove the radiator cap and check the engine coolant
level of the radiator. If it has dropped, repeat steps (d) to
(g).
(g) Bleed air from water pump.
Set the vehicle in the following conditions:

Ignition switch ON

Blower speed control dial to LO

Temperature control dial to MAX. HOT
(h) Operate the water pump in the following conditions:

The engine stopped

The blower switch ON

Temperature control dial at MAX. HOT
HINT:
Operate the water pump until a sound of the air±containing en-
gine coolant can not be heard from the heater core.
(i) When the engine coolant remains full, fill the radiator res-
ervoir tank with engine coolant to the maximum level.
3. CHECK FOR COOLANT LEAKS
4. CHECK ENGINE COOLANT SPECIFIC GRAVITY IS
CORRECT

CO143±01
Z00570
Radiator Cap Tester
Radiator Cap
30° or More CO±14
± COOLINGRADIATOR AND CONDENSER MODULE
2001 PRIUS (RM778U)
ON±VEHICLE INSPECTION
1. REMOVE RADIATOR CAP
CAUTION:
To avoid the danger of being burned, do not remove the ra-
diator cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
2. INSPECT RADIATOR CAP
NOTICE:

If the radiator cap has contaminations, always rinse
it with water.

Before using a radiator cap tester, wet the relief valve
and pressure valve with engine coolant or water.

When performing steps (a) and (b) below, keep the ra-
diator cap tester at an angle of over 30°above the hor-
izontal.
(a) Using a radiator cap tester, slowly pump the tester and
check that air is coming from the vacuum valve.
Pump speed: 1 push/(3 seconds or more)
NOTICE:
Push the pump at a constant speed.
If air is not coming from the vacuum valve, replace the radiator
cap.
(b) Pump the tester and measure the relief valve opening
pressure.
Pump speed: 1 push within 1 seconds
NOTICE:
This pump speed is for the first pump only (in order to close
the vacuum value). After this, the pump speed can be re-
duced.
Standard opening pressure:
74 ± 103 kPa (0.75 ± 1.05 kgf´cm
2, 10.7 ± 14.9 psi)
Minimum opening pressure:
79 kPa (0.8 kgf´cm
2, 11.5 psi)
HINT:
Use the tester's maximum reading as the opening pressure. If
the opening pressure is less than minimum, replace the radiator
cap.

B11773
Radiator Cap Tester
± COOLINGRADIATOR AND CONDENSER MODULE
CO±15
2001 PRIUS (RM778U)
3. INSPECT COOLING SYSTEM FOR LEAKS
(a) Fill the radiator with coolant and attach a radiator cap tes-
ter.
(b) Warm up the engine.
(c) Pump it to 118 kPa (1.2 kgf´cm
2, 17.1 psi), and check that
the pressure drops.
If the pressure drops, check the hoses, radiator or water pump
for leaks. If no external leaks are found, check the heater core,
cylinder block and head.
4. REINSTALL RADIATOR CAP