3054B Industrial Engine Caterpillar

• The pressure type cooling system can operate safely at a higher temperature than the boiling point of water at a range of atmospheric pressures.

• The pressure type cooling system prevents cavitation in the water pump.

Cavitation is the sudden generation of low pressure bubbles in liquids by mechanical forces. The generation of an air or steam pocket is much more difficult in a pressure type cooling system.

Regular inspections of the cooling system should be made in order to identify problems before damage can occur. Visually inspect the cooling system before tests are made with the test equipment.

Visual Inspection Of The Cooling System

1. Check the coolant level in the cooling system.

2. Look for leaks in the system.

3. Inspect the radiator for bent fins and other restriction to the flow of air through the radiator.

4. Inspect the drive belt for the fan.

5. Inspect the blades of the fan for damage.

6. Look for air or combustion gas in the cooling system.

7. Inspect the radiator cap for damage. The sealing surface must be clean.

8. Look for large amounts of dirt in the radiator core. Look for large amounts of dirt on the engine.

9. Shrouds that are loose or missing cause poor air flow for cooling.

Testing The Cooling System

Remember that temperature and pressure work together. Both the temperature and the pressure must be checked when a problem with the cooling system exists. The pressure of the cooling system will have an effect on the temperature of the cooling system. Review Illustration 1 in order to determine the following effects on the boiling point of water:

• Pressure

• Height above sea level

Illustration 1	g00313203
Cooling system pressure at specific altitudes and boiling points of water

Test Tools For The Cooling System

Illustration 2	g00313246
4C-6500 Digital Thermometer

The 4C-6500 Digital Thermometer is used in the diagnosis of problems that cause overheating or overcooling in the engine. This tool can be used to check the temperature in several areas of the cooling system. The testing procedure is in Tool Operating Manual, NEHS0554.

Illustration 3	g00313263
8T-2700 Blowby/Air Flow Indicator

The 8T-2700 Blowby/Air Flow Indicator is used to check the air flow through the radiator core. The operating instructions are included with the tooling.

Illustration 4	g00022794
9U-7400 Multitach Tool Group

The 9U-7400 Multitach Tool Group is used to measure the fan rpm. The testing procedure is in Tool Operating Manual, NEHS0605.

Adding The Antifreeze

Do not add pure antifreeze to the cooling system in order to adjust the concentration of antifreeze. The pure antifreeze increases the concentration of antifreeze in the cooling system. The increased concentration increases the concentration of dissolved solids and undissolved chemical inhibitors in the cooling system.

Add an antifreeze and water mixture in the concentration which provides the desired freeze protection. Use the following chart in order to determine the correct concentration of antifreeze in water to use.

Testing The Pressure Cap

One cause for a pressure loss in the cooling system can be a faulty seal on the radiator pressure cap.

Illustration 5	g00313363
9S-8140 Pressurizing Pump (1) Release valve (2) Adapter (3) Hose

The 9S-8140 Pressurizing Pump pressurizes the cooling system in order to test for leaks.

Illustration 6	g00313383
Pressure cap that is mounted on the radiator (4) Sealing surface between the pressure cap and the radiator

Use the following procedures to inspect the pressure cap and test the pressure cap.

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Pressurized system: Hot coolant can cause serious burn. To open cap, stop engine, wait until radiator is cool. Then loosen cap slowly to relieve the pressure.

1. When the engine has cooled, loosen the pressure cap to the first stop. Remove the pressure cap when the pressure is released from the cooling system.

2. Inspect the pressure cap carefully. Look for damage to the seal. Look for damage to the surface that seals. Remove any debris on the cap, the seal, or the sealing surface.

3. Put the pressure cap on the 9S-8140 Pressurizing Pump.

4. Observe the exact pressure when the pressure cap opens.

5. Compare the pressure to the pressure rating that is found on the top of the pressure cap. The pressure cap is faulty if the pressure cap opens at a pressure beyond the range that is found on the pressure cap. Replace a faulty pressure cap with a new part.

Testing The Radiator And Cooling System For Leaks

Use the following procedure to test the radiator and the cooling system for leaks.

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Pressurized system: Hot coolant can cause serious burn. To open cap, stop engine, wait until radiator is cool. Then loosen cap slowly to relieve the pressure.

1. When the engine has cooled, loosen the pressure cap to the first stop. Allow the pressure to release from the cooling system. Then remove the pressure cap.

2. Make sure that the coolant covers the top of the radiator core.

3. Put the 9S-8140 Pressurizing Pump on the radiator.

4. Use the pressurizing pump to increase the pressure to an amount of 20 kPa (3 psi) more than the operating pressure of the pressure cap.

5. Inspect the radiator for leakage.

6. Inspect all connections and hoses of the cooling system for leaks.

   The radiator and the cooling system do not have leakage if all of the following conditions exist:

   • You do not see any leakage after five minutes.

   • The dial indicator remains constant beyond five minutes.

   • The reading on the dial indicator decreases, and you do not observe any outside leaks.

7. If any leakage exists on the inside of the cooling system, identify the location of the leakage. Repair the source of the leak in the cooling system.

Testing The Water Temperature Regulator

1. Remove the water temperature regulator from the engine.

2. Hang the water temperature regulator in a pan of water. Put a thermometer in the water. Put the water temperature regulator completely under water. Do not allow the water temperature regulator to be in contact with the pan.

3. Heat the water in a container. Stir the water in order to keep all of the water at the same temperature.

4. Replace the water temperature regulator if the water temperature regulator does not open at the temperatures that are found in Specifications, "Water Temperature Regulator".

Engine And Cooling System Heat Problems

Note: Use a coolant recovery system in order to collect any coolant which drains from the coolant system.

1. The following conditions indicate that a heat problem exists.

   1. Hot coolant is released through the pressure cap during the normal operation of the engine. Hot coolant can also be released when the engine is stopped.

   2. Hot coolant is released from the coolant system but not through the pressure cap during normal operation of the engine. Hot coolant can also be released when the engine is stopped.

   3. Coolant must be added frequently to the cooling system. The coolant is not released through the pressure cap or through an outside leak.

2. If any of the conditions in Step 1 exist, perform the following procedures:

   1. Run the engine at medium idle, which is approximately 1200 rpm, for three minutes after the high idle shuts off. Running the engine at medium idle will allow the engine to cool before the engine is stopped.

3. Perform the following procedures in order to determine if the pressure cap is damaged or if a leak exists in the cooling system.

   1. Perform the "Visual Inspection Of The Cooling System" procedures.

   2. Perform the "Testing The Pressure Cap" procedures.

   3. Perform the "Testing The Radiator And Cooling System For Leaks" procedures.

   4. Check the tension of all belts on the engine. Refer to the Testing And Adjusting, "Belt Tension Chart" for more information.

4. If the coolant does not flow through the radiator and through other components of the cooling system, perform the following procedures.

   1. Perform the "Testing The Water Temperature Regulator" procedures.

   2. Clean the radiator and other components with hot water or steam at low pressure. Detergent in the water may also be used. Compressed air may be used to remove materials from the cooling system. Identify the cause of the restriction before you choose the method for cleaning.

   3. Straighten any fins of the radiator if the fins are bent.

5. Check the high idle of the engine. The engine may overheat if the high idle rpm is set too high.

6. Timing of the engine which is incorrect may also cause overheating of the engine. Late timing creates more heat in the engine. Early timing creates less heat in the engine.

   Note: If the timing of the engine is too early, the exhaust valves may be burned and damage to the exhaust manifold may occur.

Cooling System Conditioner

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Supplemental cooling system additive contains alkali. To prevent personal injury, do not drink, avoid contact with the skin and eyes.

Caterpillar Cooling System Conditioner can be used with an antifreeze or without an antifreeze of ethylene glycol base in the coolant.

When the conditioner is added to the coolant, the cooling system must be flushed and the cooling system must be cleaned . Refer to Operation and Maintenance Manual for additional information.