REMOVE AND TEST THERMOSTATS
CAUTION: Explosive release of fluids from
pressurized cooling system can cause serious
burns. Do not drain coolant until coolant
temperature is below operating temperature.
Always loosen cooling system filler cap,
radiator cap, or drain valve slowly to relieve
1. Visually inspect the area around the water manifold for
leaks. Partially drain coolant from the cooling system.
2. Remove thermostat cover (A) with gasket. Remove
Removing Thermostat Cover
and discard all gasket material.
3. Remove thermostats.
4. Inspect thermostats for debris or damage, and test
each thermostat using an approved testing procedure.
See INSPECT THERMOSTAT AND TEST
THERMOSTAT OPENING TERMPERATURE in Group
105 for testing procedure. Thermostats should start to
open within the range specified below.
82C (180F) Thermostat--Specification
Opening Temperature .......................................... 80--84C (175--182F)
If either thermostat fails to open within this range, replace
both thermostats as a set.