CORE AS-CONDENSER 1252873 - 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
The HVAC water valve actuator may be defective on the machines listed in this publication. If the actuator is defective, the operator may experience intermittent temperature control from the HVAC system.The actuators are used to drive the water valve for the cab heating system. The issue with the actuator is a worm drive gear inside is not formed correctly and can cause the actuator to not function properly, especially when the water valve it drives is exposed to higher machine cooling system pressure and flow.There are two affected actuators:
279-0850 Actuator
265-9620 ActuatorSolution
Note: The actuator will be attached to the water valve for the cab heating system. The location of this actuator will therefore be on the cab. Look for the actuator in the coolant line circuit on the cab.The actuators have a build date included on the label that will help identify a good part from a bad part.If the actuator is determined to be bad through the build date, the actuator must be replaced.
BAD = Build Date 01 January 2017to 01 March 2017
GOOD = Build date Before01 January 2017and After 01 March 2017
Illustration 1 g06206481
Typical example of a label on an actuator
(A) Build Date
Illustration 2 g06206489
Typical view of an actuator
(B) FastenerNote: In some instances the label on the actuator may be difficult to read. If the label is difficult to read, the actuator must be removed to read the label. Typically the actuator is removed by loosening three fasteners (B) as shown in Illustration 2. The torque on fasteners (B) is 1.7 N m (15 lb in).Replacing an Actuator
Follow the instruction shown below for a description of the necessary position of the water valve adapter when installing the new actuator.
Illustration 3 g06206519
(C) Actuator mounting points
(D) 'Mid' Position
(E) Adapter bushingThe actuator drive will arrive in the position shown in Illustration 3. You can manually adjust the position of the valve adapter to match Mid Position (D). The position does not have to be exact.Note: Ensure that adapter bushing (E) stays with the valve.Water Valve Removal
If the actuator cannot easily be removed from the water valve assembly due to its location or orientation in the cab, you may have to remove the entire water valve assembly. Removing the entire water valve assembly is not the preferred method.
Disconnect the water valve assembly from the electrical connector.
Disconnect hoses.
Remove and retain bolts, nuts, and washers for use during the installation procedure.
Replace the Actuator with new part.
Install water valve assembly using the procedure below.
Remove the heater hose and clean the surface of the formed tube.
Illustration 4 g06206524
(AA) 25.4 mm (1.00 inch)
Reinstall the heater hose to the formed tube with dimensions (A) from bead to hose end. Refer to Illustration 4.
Inspect the hose clamp for damage and replace as needed.
Illustration 5 g06206541
(AB) 5.00 mm (0.197 inch)
Position the hose clamp to the correct distance from the hose bead. The distance from the end of the hose