Toyota Prius: Thermostat

• Removal
• Inspection
• Installation

Removal

REMOVAL

CAUTION / NOTICE / HINT

COMPONENTS (REMOVAL)

Procedure		Part Name Code
1	NO. 1 ENGINE UNDER COVER ASSEMBLY	51410	-	-	-
2	DRAIN ENGINE COOLANT (for Engine)	-	-		-

Procedure		Part Name Code
3	RADIATOR SUPPORT OPENING COVER	53289A	-	-	-
4	INLET NO. 2 AIR CLEANER	17752	-	-	-
5	AIR CLEANER CAP SUB-ASSEMBLY	17705	-	-	-
6	AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY	17801	-	-	-
7	AIR CLEANER CASE SUB-ASSEMBLY	17701	-	-	-
8	AIR CLEANER BRACKET	17771A	-	-	-
9	INLET NO. 1 AIR CLEANER	17751	-	-	-

Procedure		Part Name Code
10	ENGINE OIL LEVEL DIPSTICK	15301	-	-	-
11	ENGINE OIL LEVEL DIPSTICK GUIDE	11452	-	-	-
12	WATER INLET WITH THERMOSTAT SUB-ASSEMBLY	16031		-	-

*A	Type A	*B	Type B
*1	NO. 2 RADIATOR HOSE	*2	NO. 3 WATER BY-PASS HOSE
*3	GASKET	*4	ENGINE OIL LEVEL DIPSTICK GUIDE O-RING
●	Non-reusable part	-	-

PROCEDURE

1. REMOVE NO. 1 ENGINE UNDER COVER ASSEMBLY

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2. DRAIN ENGINE COOLANT (for Engine)

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3. REMOVE RADIATOR SUPPORT OPENING COVER

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4. REMOVE INLET NO. 2 AIR CLEANER

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5. REMOVE AIR CLEANER CAP SUB-ASSEMBLY

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6. REMOVE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

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7. REMOVE AIR CLEANER CASE SUB-ASSEMBLY

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8. REMOVE AIR CLEANER BRACKET

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9. REMOVE INLET NO. 1 AIR CLEANER

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10. REMOVE ENGINE OIL LEVEL DIPSTICK

11. REMOVE ENGINE OIL LEVEL DIPSTICK GUIDE

12. REMOVE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

*1

No. 2 Radiator Hose

*2

No. 3 Water By-pass Hose

(1) Slide the 2 clips and disconnect the No. 2 radiator hose and No. 3 water by-pass hose from the water inlet with thermostat sub-assembly.

HINT:

When disconnecting the No. 3 water by-pass hose, slide the clip, rotate the hose and pull it straight off the pipe.

*A

Type A

*B

Type B

Inspection

INSPECTION

PROCEDURE

1. INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

Pre-procedure1

(a) Immerse the water inlet with thermostat sub-assembly in water and then gradually heat the water.

Procedure1

(b) Check that the valve of the water inlet with thermostat sub-assembly opens at the specified temperature.

Standard Valve Opening Temperature:

Specified Condition	Result
80 to 84 °C 176 to 183 °F	°C °F

If the result is not as specified, replace the water inlet with thermostat sub-assembly.

Procedure2

(c) Check the valve lift. Standard Valve Lift: Compression Spring Shape Condition Specified Condition Tapered 95°C (203°F) 10 to 14 mm 0.394 to 0.551 in. Straight 95°C (203°F) 8 mm or higher 0.315 in. or higher If the result is not as specified, replace the water inlet with thermostat sub-assembly.

*A Compression Spring Shape: Tapered *B Compression Spring Shape: Straight *a Valve Lift *b Compression Spring

Procedure3

(d) Check that the valve is fully closed when the water inlet with thermostat sub-assembly is at low temperatures (below 77°C (171°F)).

If it is not fully closed, replace the water inlet with thermostat sub-assembly.

Post-procedure1

(e) None

Installation

INSTALLATION

CAUTION / NOTICE / HINT

COMPONENTS (INSTALLATION)

Procedure		Part Name Code
1	WATER INLET WITH THERMOSTAT SUB-ASSEMBLY	16031	-	-	-
2	ENGINE OIL LEVEL DIPSTICK GUIDE	11452	-	-	-
3	ENGINE OIL LEVEL DIPSTICK	15301	-	-	-

*A	Type A	*B	Type B
*1	NO. 2 RADIATOR HOSE	*2	NO. 3 WATER BY-PASS HOSE
*3	GASKET	*4	ENGINE OIL LEVEL DIPSTICK GUIDE O-RING
	N*m (kgf*cm, ft.*lbf): Specified torque	●	Non-reusable part

Procedure		Part Name Code
4	INLET NO. 1 AIR CLEANER	17751	-	-	-
5	AIR CLEANER BRACKET	17771A	-	-	-
6	AIR CLEANER CASE SUB-ASSEMBLY	17701	-	-	-
7	AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY	17801	-	-	-
8	AIR CLEANER CAP SUB-ASSEMBLY	17705		-	-
9	INLET NO. 2 AIR CLEANER	17752		-	-
10	RADIATOR SUPPORT OPENING COVER	53289A	-	-	-

N*m (kgf*cm, ft.*lbf): Specified torque

-

-

Procedure		Part Name Code
11	ADD ENGINE COOLANT (for Engine)	-	-		-
12	INSPECT FOR COOLANT LEAK (for Engine)	-	-	-
13	NO. 1 ENGINE UNDER COVER ASSEMBLY	51410	-	-	-

N*m (kgf*cm, ft.*lbf): Specified torque

-

-

PROCEDURE

1. INSTALL WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

Torque:

10 N·m {102 kgf·cm, 7 ft·lbf}

2. INSTALL ENGINE OIL LEVEL DIPSTICK GUIDE

Torque:

21 N·m {214 kgf·cm, 15 ft·lbf}

3. INSTALL ENGINE OIL LEVEL DIPSTICK

4. INSTALL INLET NO. 1 AIR CLEANER

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5. INSTALL AIR CLEANER BRACKET

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6. INSTALL AIR CLEANER CASE SUB-ASSEMBLY

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7. INSTALL AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

8. INSTALL AIR CLEANER CAP SUB-ASSEMBLY

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9. INSTALL INLET NO. 2 AIR CLEANER

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10. INSTALL RADIATOR SUPPORT OPENING COVER

11. ADD ENGINE COOLANT (for Engine)

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12. INSPECT FOR COOLANT LEAK (for Engine)

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13. INSTALL NO. 1 ENGINE UNDER COVER ASSEMBLY

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