"U" BOLT 5K6151 - Caterpillar

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
On certain Series M-Series Medium Wheel Loaders, certain machine conditions can cause a delay in transmission pump priming immediately after engine start. Pump priming should normally occur in less than 8 seconds. The conditions that may result in delayed pump priming are when the engine has been off for more than 2 minutes but less than 1 hour, and when transmission oil temperatures are above 40° C (104° F). If the operator puts the machine into gear, the gear will not engage until the pump primes. The machine will not move, and a "Transmission Slip Detect" event is likely to occur. Delayed pump priming alone does not indicate a transmission pump failure, unless other symptoms of low pressure are present. Refer to the Troubleshooting guide for your machine.Solution
Complete the following interim corrective action steps until a permanent solution is found.
Update to the latest available transmission software flash file. Later versions of transmission software will delay activation of the "Transmission Clutch Slip Detect" logic until after the expected transmission pump priming time.
Verify that all hose clamps and fittings in the suction line to the transmission pump are tight. Even if no visible oil leakage is visible, a loose connection can contribute to pump priming problems.
Verify that the transmission oil fill level is correct. If pump priming issues are occurring, fill the transmission to the upper end of the allowable range, but DO NOT OVERFILL.
Illustration 1 g06031130
Right Side View of Transmission
(A) 9X-2614 Connector
The 950M and 962M have an external purge connector (A) and hose on the pump that help pump priming. If this orifice is blocked by debris, pump priming may take longer than expected. Remove connector (A) and inspect to ensure that connector (A) is clear. Refer to the illustration.
If starting the engine under the conditions that make delayed pump priming likely, increase the engine speed to 1200 RPM for a few seconds before placing the machine into gear. This will help the pump prime.
If Transmission Slip Detected events are occurring at times other than immediately after engine start, refer to the Troubleshooting guide for your machine.
Contact DSN for more assistance. Later versions of transmission software will automatically capture and store a Data Snapshot file of the most recent Transmission Slip event. This file can be downloaded via Cat Electronic Technician. Provide this file via DSN to help with troubleshooting.Listed below are the event codes for the clutch slip events.
E2201-2 Transmission Slip Detected In FIRST Forward Gear.
E2202-2 Transmission Slip Detected In SECOND Forward Gear.
E2203-2 Transmission Slip Detected In THIRD Forward Gear.
E2204-2 Transmission Slip Detected In FOURTH Forward Gear.
E2205-2 Transmission Slip Detected In FIFTH Forward Gear.
E2301-2 Transmission Slip Detected In FIRST Reverse Gear.
E2302-2 Transmission Slip Detected In SECOND Reverse Gear.
E2303-2 Transmission Slip Detected In THIRD Reverse Gear.
E2304-2 Transmission Slip Detected In FOURTH Reverse Gear.Reference: Troubleshooting, UENR3111,