Cooling System: Inspection

WARNING: This page is about a different car, the 2004 Scion xB. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT THERMOSTAT
HINT:

The valve opening temperature is inscribed on the thermostat.

Fig 1: Locating Valve Opening Temperature
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Immerse the thermostat in water and gradually heat the water.
2. Check the valve opening temperature of the thermostat.
  Valve opening temperature:
  
  80 to 84°C (176 to 183°F)
  
  If the valve opening temperature is not as specified, replace the thermostat.
  
  Fig 2: Checking Valve Opening Temperature Of The Thermostat
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the valve lift.
  Valve lift:
  
  Fig 3: Valve Lift Reference Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the valve lift is not as specified, replace the thermostat.
4. Check that the valve is fully closed when the thermostat is at low temperature (below 77°C (171°F)).
If not closed, replace the thermostat.

Fig 4: Checking Valve Lifting
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT RADIATOR CAP SUB-ASSY
NOTE:
- If the radiator cap is contaminated, rinse it with water.
- Before using a radiator cap tester, wet the relief valve and pressure valve with engine coolant or water.
- When performing following steps a and b and , keep the tester at an angle of over 30° above horizontal.
1. 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
  
  NOTE: Push the pump at a constant speed.
  
  If air is not coming from the vacuum valve, replace the radiator cap.
2. Pump the tester and measure the relief valve opening pressure.
  Pump speed: 1 push within 1 second
  
  Fig 5: Checking Radiator Cap
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NOTE: The above pump speed is for the first pump only (in order to close the vacuum valve). After the first pump, the pump speed can be reduced.
1. Standard opening pressure:
2. 93 to 123 kPa (0.95 to 1.25 kgf/cm ², 13.5 to 17.8 psi) Minimum opening pressure:
3. 78 kPa (0.8 kgf/cm ², 11.3 psi)
If the opening pressure is less than minimum, replace the radiator cap.

HINT:

Use the tester's maximum reading as the opening pressure.
INSPECT WATER PUMP ASSY
1. Visually check the drain hole for coolant leakage. If leakage is found, replace the water pump.
2. Turn the pulley, and check that the water pump bearing moves smoothly and does not make noise.
If necessary, replace the water pump.

Fig 6: Inspecting Water Pump Assy
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002