ENGINE AR-CORE 3773487 - Caterpillar

3300, 3400 Families Of EnginesReference: Engine News, October 1991, Page 1, "Air Filter Maintenance".The light green gasket material on the secondary air filter elements may stick to the filter housing when the secondary filter is removed.
Be sure to check the area where the secondary air filter gasket contacts the filter housing for stuck and/or torn gasket material. This area must be clean and free of gasket material to prevent an air leak path past the secondary air filter.When installing a new secondary air filter element with a light green gasket (date coded MAR88 through DEC91), put a light coat of 1U6396 O-ring Assembly Compound on the face of the light green gasket. This will help prevent the gasket material from sticking to the filter housing.
Most secondary air filter elements date coded JAN92 and later have light gray gasket material. This new gasket material will help prevent the gasket from sticking to the filter housing. Some secondary air filter elements date coded JAN92 and later may still have the light green gasket material, but these gaskets have an improved antisick coating. All secondary air filter elements date coated JAN92 and later DO NOT require the coat of 1U6396 O-ring Assembly Compound at assembly.
Tighten the retaining nuts for the secondary air filter element to a torque of 27 4 N m (20 3 lb ft).