HOSE AS 5399013 - Caterpillar

The Transmission Does Not Operate in THIRD GEAR FORWARD or REVERSE
Check lockout control.
Check the gear lockout control in order to determine whether the gear is available. The CaterpillarElectronic Technician ET service tool is required. Expected Results
Maximum track speed for FORWARD and REVERSE is less than 2.5 Results
YES: operate in third gear because third gear is locked out. Stop.
NO: Proceed to Step 3.
Use Cat ET to check for the following diagnostics codes:
1403-5 Transmission Solenoid 3: Current Below Normal
1403-6 Transmission Solenoid 3: Current Above NormalNote: If any diagnostic codes are present repair the cause of the diagnostic codes before proceeding. Refer to Troubleshooting, "Solenoid Valve - Test"
Operate the machine. The probable cause of the problem is the transmission or the brakes. The following steps help you determine a starting point for troubleshooting.
Use CaterpillarElectronic Technician ET
Start the engine.
Operate the engine at high idle.
Shift the transmission into THIRD GEAR FORWARD.
Attempt to operate the machine. Expected Results
The engine speed decreases.Results
OK: Check the brake pressure first. If the brake pressure is low, then the brake does not release. Proceed to Step 4.
NOT OK: Check the pressure to the transmission modulating valve first. Proceed to Step 5.
Check the brake pressure. Reference: Refer to Specifications, Systems