0553142 JOHNSON SCREW, Adjustment

Introduction
The information contained in the special instruction guides the user to perform a test procedure for checking the functionality of jacket water heater for proper operation.Important Safety Information
Do not perform any procedure in this special instruction until you have read this special instruction and you understand this information. Use only proper tools and observe all precautions that pertain to the use of those tools. Failure to follow these procedures can result in personal injury. The following procedures should also be observed.Work Safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. Ensure that any tool, procedure, work method, or operating technique you use that is not recommended by Caterpillar is safe.Ensure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance, or repair procedure that are used.
Do not operate or work on this equipment unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in serious injury or death.
Required Tooling
Philips screwdriver (Explosion proof models may require slip-joint pliers).
Needle nose pliers or nut driver (For removing the connectors from the element pins.)
OhmmeterTest Procedure for Jacket Water Heater
Disconnect the heater from the power source.
For heaters equipped with a thermostat, allow the coolant to cool down below the thermostat range (or remove the heater from the engine).
Illustration 1 g03406443
Be sure to remove all of the wires from the terminals to avoid getting a false reading. Check for continuity with an ohmmeter between the element terminals (A) inside the electrical box at the element end of the heater. If continuity exists between these terminals, the heater is fine and the problem is improper installation, faulty wiring, or an air pocket. If there is no continuity, continue testing the elements and thermostat as outlined below.
Illustration 2 g03406451
In multiple element configurations, one element can fail while the others remain functioning. This lead to a reduced wattage but not a complete failure. If this occurs, remove the jumpers and measure the elements separately (B). Make sure that the jumper position is noted so they can be properly reassembled.
Illustration 3 g03406453
If there is continuity through the element, check for continuity across the thermostat terminal (C) .Note: Ensure that the temperature is well below the thermostat rating.
If there is no continuity between the element or thermostat terminals the heater has failed. The next step is to determine the cause of failure.