Usage:
CONFIDENTIAL TIBU2708-00
|
TECHNICAL INFORMATION BULLETIN |
MAY 19, 2004 |
|
EXCAVATORS |
5110B (AAA1-UP), 5110B L (AAK1-UP), 5110B MH (AAT1-UP) |
|
COMPONENT CODE |
4285 |
SUBJECT: DISASSEMBLY OF THE STICK CYLINDERS AND OF THE BUCKET CYLINDERS MAY BE DIFFICULT
PROBLEM:
Disassembly of the stick and bucket cylinders with threaded pistons has been difficult or impossible because in some cases the threaded pistons are stuck on the rod so tightly that the pistons cannot be loosened and removed. This problem prevents replacement of the rod seals and has resulted in replacement of the entire cylinder group.
Refer to Table 1 for a list of all stick cylinders and bucket cylinders with pistons threaded onto rods.
|
Part Number |
Description |
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Cylinder Gp (Stick) |
|
|
Cylinder Gp (Stick-ME) |
|
|
Cylinder Gp (Stick-ME) |
|
|
Cylinder Gp (Bucket-ME) |
SOLUTION:
If the piston cannot be loosened from the rod, heat the piston using an acetylene torch with a rosebud tip. Heat the piston uniformly around the outer diameter for five to ten minutes. Note: Do not heat piston above 500?F. Then apply loosening torque to the piston using the two drilled holes in the piston.
Although it is not known if this procedure will result in the piston being able to be removed in all cases, this procedure has been used successfully on some rods with stuck pistons.
If the rod is re-useable, rework the threads for the piston as shown in Illustration 1. If the piston is re-useable, rework the piston as needed to provide 11.4 mm x 45 deg (0.43 inch x 45 deg) Chamfer and four 17.5 mm (0.69 inch) dia. holes as shown in Illustration 2.
Illustration 1. Typical rod assembly
Illustration 2. Typical piston assembly
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