MOTOR GP HYD 10R3337 - Caterpillar

TECHNICAL INFORMATION BULLETIN July 27, 2005
Mini Hydraulic Excavators
304 (NAD1-Up)
304.5 (ANR1-Up, WAK1-Up)
305 (DGT1-Up, DSA1-Up)
Component Code(s) 6129, 6513SUBJECT: LINKAGE MODIFICATION IMPROVES QUICK COUPLER OPERATION ON MINI HYDRAULIC EXCAVATORS
PROBLEM:
The MHE coupler may not engage or disengage readily when used in conjunction with the 228-2433 link.
SOLUTION:
The solution is to provide adequate clearance for the engagement spring to travel throughout its intended path.
The rework involves modifying 228-2433 link that is part of the machine stick assembly. By modifying this part as shown in the following illustrations, the coupler spring will have sufficient clearance to operate correctly. This is the quickest way to solve this problem and this fix can be performed with the coupler on the machine.
Remove the bucket from the coupler then lower the coupler to the ground
Carefully remove the coupler retaining pin from the 228-2433 link.
Place the stick in a position so that the coupler is about 3 ft above the ground. Allow the coupler to hang by the remaining pin at the stick.
Rotate the 228-2433 link upward and secure it to the hydraulic cylinder with a plastic tie wrap. Place a rag between the link and the cylinder in order to protect the cylinder.
Be sure to wear a protective face shield and gloves. Use a small abrasive disc grinder to remove up to 5mm of material from the area that is indicated in illustrations 1 through 4.
Paint the area with Caterpillar yellow paint.
Remove the tie wrap and reassemble the coupler to the link.
Test the operation of the coupler with the link. Refer to the Operation and Maintenance Manual of the excavator for operating instructions for the coupler.
Illustration 1
Illustration 2
Illustration 3
Illustration 4
COPYRIGHT 2005 CATERPILLAR
ALL RIGHTS RESERVED