Service manual

CLOSED COOLED MODELS

SERVICE MANUAL NUMBER 26

90-861329--1 MARCH 1999 Page 6B-9

Thermostat

Removal

1. Drain coolant from cylinder block and exhaust manifold.

2. Disconnect hoses from thermostat cover attaching bolts and lock-washers, then remove

cover and gasket.

3. Remove thermostat from thermostat housing.

73575

a-Bolts

b-Reservoir

c-Thermostat Housing

Testing

1. Clean thermostat in soap and water to remove any deposits or debris.

2. Inspect thermostat for corrosion or other visible damage.

3. If thermostat is suspected of producing insufficient engine temperature, check

thermostat for leakage by holding it up to lighted background. Light leakage around the

thermostat valve indicates that thermostat is not closing completely and should be

replaced. (A small amount of leakage at one or two points around the valve perimeter

is acceptable.)

72717

Brass Thermostat (Stainless Steel Similar)

a-Check for Light Leakage Around Perimeter of Valve

Index