TUBE AS 1390681 - Caterpillar

Probable Causes
Mechanical system
Hydraulic system
Hydraulic oil contamination
Power shift solenoidRecommended Actions
Thoroughly check the mechanical system and the hydraulic system.
Use ET to check for diagnostic codes. Repair all causes for any logged diagnostic codes and/or active diagnostic codes. Verify that unstable hydraulic function still exists.
Use the "Override Parameters" feature under the "Diagnostics" menu on ET to set the override for the power shift solenoid.
Set the override for the power shift solenoid at 10 percent.Note: Changing screens on ET will disable the override function.
Open the bucket and extend the stick. Then, lower the boom.
Perform a boom raise operation until the engine speed drops below 1300 rpm. Do not stall the engine. The bucket should raise smoothly and engine speed should recover.
Repeat Steps 3.a through 3.c while increasing the override value in 10 percent increments until the engine speed does not recover.Note: Engine speed will not recover at some override value. Stop the boom raise operation before stalling the engine.
Boom raise operation should be smooth at all override values. If the boom raise operation is unstable or the boom raise operation exhibits a series of repetitive jerks, check the hydraulic oil for contamination.
If the problem still exists, replace the power shift solenoid and calibrate the new power shift solenoid. Refer to Troubleshooting, "Power Shift Solenoid - Calibrate".