90303-ZY3-000 Honda NUT, HEX. (18MM) (Honda Code 6994149).

Ensure that the engine is stopped before any servicing or repair is performed.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Cat Dealer Service Tool Catalog" or refer to Special Publication, PECJ0003, "Cat Shop Supplies and Tools Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
The crankcase breather is a very important component to keep your engine emissions compliant.
The filter element within the crankcase breather must be serviced at the prescribed service interval.
The correct filter element must be installed before the engine is operated.
The installation of the filter element is very important.
The quality of the filter element that is installed is very important.For information on aftermarket products, refer to Operation and Maintenance Manual, "Product Description". Within that section, refer to the title “Aftermarket Products and Caterpillar Engines”.The breather element can be serviced from the top position or the breather element can be serviced from the bottom position.Top Service
Illustration 1 g03090965
Typical example
Ensure that dirt cannot enter the breather assembly. Ensure that the outside body of the breather assembly is clean and free from damage. Place a container under the breather assembly.
Rotate the top cap (1) counterclockwise into the unlocked position. Remove the top cap from the body of the breather (3) and remove the filter element (2).
Illustration 2 g03090963
Typical example
Remove the old seal (4) and install a new seal.Note: The cut away from section (5) in the top cap allows access to the seal.
Illustration 3 g03090938
Typical example
(A) Alignment position
(B) Alignment position
Install a new filter element into the breather body (3). Ensure the correct position of the element, refer to illustration 3. Align position (A) on the top cap to position (B) on the filter element.
Illustration 4 g02346577
Typical example
Install the top cap (1). Rotate the top cap by hand clockwise until the top cap locks into the locked position (C) on the breather body.
Remove the container.Bottom Service
Ensure that dirt cannot enter the breather assembly.
Illustration 5 g02346498
Typical example
(X) Alignment mark
(Y) Alignment mark
Ensure that the outside body of the breather assembly is clean and free from damage. Place a container under the breather.
Remove the tube connection (1). Ensure that dirt cannot enter the tube connection. Note the position of the alignment marks (X and Y). Rotate the bottom cap (2) counterclockwise to release the cap and the filter element (4) from the breather body (3).
Illustration 6 g03090968
Typical example
(A) Alignment postion
(B) Alignment postion
Remove the filter element (4). Remove the seal (5).Note: The bottom cap has a section that allows access to remove the seal.
Install a new seal (5). Install a new filter element into the bottom cap (2).
Align position (A) on the top cap to position (B) on the filter element. Refer to illustration 6.
Install the assembly of the filter element and the bottom cap (2). Rotate the bottom cap by hand clockwise until the bottom cap locks into the locked position on the breather body. Ensure that the alignment marks (X and Y) are correctly aligned. Refer to illustration 5.
Install tube connection (1). Ensure that the retaining clips on the tube connection are correctly engaged. Remove the container.Check the System
Illustration 7 g02346500
Typical example
Inspect the breather tube (1) for damage. Ensure that the outlet (2) is clean and free from any obstructions. Ice can cause obstructions in adverse weather conditions.