ADAPTER GP-AIR CLEANER 7W0687 - Caterpillar

Introduction
This Special Instruction provides information to troubleshoot hydraulic cylinder seal failures on the machines that are listed above.Troubleshooting Guide
Oil Leaking Past the Rod Piston and Cylinder Head
Problem 1
Surface rust or a scratch on the cylinder rod that can be felt with a fingernail.Solution
Check the seals for damage. Rework or replace any damaged components.Problem 2
Delamination of the cylinder rod plating.Solution
Replace or replate the cylinder rod. Check the seals and piston rod wear bands. Make sure that machines or parts are stored following the long-term storage guidelines.Rod U-Cup/Buffer Seal
Problem 1
Contamination is stuck on the inner or outer lip.Solution
Remove the contamination. If the u-cup/buffer seal is damage, replace the u-cup/buffer seal.Problem 2
The inner or outer seal is scratched.Solution
Replace the seals.Problem 3
The lip and groove of the seal are partly carbonized or burnt.Solution
The combustion of the air/hydraulic oil in the hydraulic cylinder may damage the seals. After replacing the seals, completely remove air by operating the cylinder at low pressure and low speed before operating the cylinder for the first time.Problem 4
The u-cup/buffer seal is hardened and chipped out or the u-cup/buffer seal lip is chipped out.Solution
Replace the u-cup/buffer seal. The u-cup/buffer seal is damaged because the oil is too hot and degraded. Check the oil temperature.Problem 5
The heel of the u-cup seal is extruded.Solution
Replace the u-cup seal. Excessive high pressure may deform the u-cup seal. Check the operating pressure. Check the buffer seal.Backup Ring
Problem
Backup ring deforms.Solution
Contamination sticks to the lip of the backup ring. Excessive high pressure may damage the backup ring. Check the operating pressure. Check the buffer seal.Wiper Seal
Problem 1
Backup ring deforms.Solution
Check for contaminants.Problem 2
The lip or other parts are damaged.Solution
Replace the wiper seal.Cylinder Rod Wear Bands
Problem 1
Excessive wear creates a large gap between the wear bands and the cylinder rod, which exceeds the wear limit of the wear bands.Solution
Replace the cylinder rod wear bands.Problem 2
The rod has a large scratch.Solution
Replace the cylinder rod wear bands. Check the cylinder rod for surface rust or a scratch.Cylinder Head
Problem
The cylinder head seal groove has surface rust or a scratch.Solution
Replace the cylinder head.