Usage:
438B (3KK1614-UP) BACKHOE LOADERS
Problem:
The Hydraulic System on the above Machine Models may exhibit excessive noise when operating the Backhoe Hydraulic Circuits.
The noise is caused by return oil passing through the 113-1984 return to tank restrictor valve. This restrictor valve is used to prevent hydraulic system drift from occurring by providing return oil back pressure. The return spring in the 113-1984 valve does not allow the poppet valve within this valve to move properly.
Solution:
Remove the 113-1984 valve from the Backhoe Control valve return oil manifold, the valve is situated on the outlet port of the manifold and is connected to the hose which directs return oil back to the return filter. Remove the spring which is located inside the valve, cut 20 mm from the free length of the spring and reinstall into the valve. Refit the valve back onto the machine and confirm that the hydraulic system is operating normally and that no excessive noise exists.
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