Verify the Swing Relief Pressure When Replacing the Swing Motor on Certain 301.4C and 301.7D CR Mini Hydraulic Excavators {5058, 7051} Caterpillar

Mini Hydraulic Excavator

301.4C (S/N: LJ31-UP; LJK1-UP)

301.7D (S/N: LJ81-UP; LJD1-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

If the swing motor or swing motor relief valves are replaced on certain 301.4C or the 301.7D CR Mini Hydraulic Excavators, the swing motor relief pressure may not be set correctly.

Solution

After replacing the swing motor or the swing motor relief valves, check the swing motor relief pressure according to the instructions in Test and Adjust. Adjust the swing motor relief pressure if not within the specified pressure. If the swing motor or swing motor relief valves have not been replaced, no action is necessary.