BODY AS-PISTON 4P7187 - 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.Problem
The 348-3400 Combustion Head Gp and the 348-3402 Combustion Head Gp have a seal that allows foreign material to pass through and cause a short in the heater.The short causes a high current that creates an ARC across the heater wire connector. This arcing is what melts the connector.
Illustration 1 g03505730
Solution
The new 433-3675 Combustion Head Gp and 433-3677 Combustion Head Gp utilize an improved seal that will help prevent foreign contamination from getting into the heater.If an ARD head failure occurs on the old ARD head, inspect the heater wire end to make sure that it is not damaged.