hi everyone. I had a problem with my cat 320L 1KL, when I moved the boom down but it went down too fast until it shook, I checked the boom control valve section and the relief valve line, but there were no stuck parts or broken springs. please help friends" thank you
I've had it happen on several B, C, and D machines. Usually its the line relief on the bucket, but 3 times it has been on the boom. Repeated impacting, ie relief rapidly opening and closing rapidly, can cause the makeup valve spring, within the relief valve, to unwind into the relief valve seat. Now, when this occurred, that cylinder would no longer hold its position. Lift the boom and it would drop. Finally, Cat introduced an updated relief, whereupon the makeup spring seat has a ledge to prevent unwinding into the relief seat. Prior to the revision, I would simply flip over the makeup spring and put the valve back in. Again, once it occurred, that cylinder would always severely drift. If yours is now acting normal, the issue may be elsewhere. IIRC, the updated line reliefs still bear the same part number, but now have a groove around the body nut to indicate that it is revised. For the life of me, I cannot find that info today to see if it applies to an A model. So, is the boom operation normal now?
boom raise, bucket, swing, arm, track are all normal, only boom down is problematic
Could the centering spring bolt on the boom down spool be backing off?
no, the boom section spool is normal. is there a pressure reducing system for the spool boom?
Check Hydraulic Fluid: Ensure your hydraulic fluid is at the correct level and in good condition. Low or contaminated fluid can affect control. Inspect Control Levers: Examine the control levers for any damage or wear that might be causing erratic movement. Valve Adjustment: Recheck the boom control valve section for any potential adjustment issues, and ensure all components are in proper working order. Professional Inspection: If the problem persists, consult a qualified heavy equipment mechanic or hydraulic technician who can perform a more in-depth diagnosis and address any potential internal hydraulic system issues.