2005/11/21 Caterpillar

Mini Hydraulic Excavator:

304 (S/N: NAD1-UP)

304.5 (S/N: WAK1-UP; ANR1-UP)

305 (S/N: DSA1-UP; DGT1-UP)

The quick coupler may not engage readily when the quick coupler is used with the 228-2433 Link and Bearing As. Also, the quick coupler may not disengage readily when the quick coupler is used with the 228-2433 Link and Bearing As. Clearance must be provided in order to allow the locking spring to travel through the spring's intended path.

Rework Procedure

The rework procedure involves the modification of the 228-2433 Link and Bearing As. The link is part of the machine's stick assembly. By modifying this link, the quick coupler's locking spring will have sufficient clearance in order to operate correctly. This procedure can be performed with the quick coupler on the machine.

1. Remove the bucket from the quick coupler. Lower the quick coupler to the ground.

2. Carefully remove the quick coupler's retaining pin from the 228-2433 Link and Bearing As .

3. Place the stick in a position so that the quick coupler is about 1 m (3 ft) above the ground. Allow the quick coupler to hang by the remaining pin at the stick.

4. Rotate the link upward. Secure the link to the hydraulic cylinder by using a plastic tie. Place a rag between the link and the cylinder in order to protect the cylinder.

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Illustration 1	g01220705

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Illustration 2	g01220716
(A) 25 mm (0.9843 inch)

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Illustration 3	g01220726
(B) 25 mm (0.9843 inch)

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Illustration 4	g01220730

5. Be sure to wear a protective face shield and gloves. Obtain a small disc grinder. Remove 5 mm (0.2 inch) of material from the area that is indicated in illustrations 1 through 4.

6. Paint the area with "Caterpillar yellow" paint.

7. Remove the plastic tie.

8. Reassemble the quick coupler to the link.

9. Test the operation of the quick coupler with the link. Refer to the Operation and Maintenance Manual of the excavator for operating instructions for the quick coupler.