Usage:
Coolant Conditioner Element
 |
At Operating Temperature, engine coolant is hot and under pressure. Steam can cause personal injury. Check coolant level ONLY, when engine is stopped and radiator cap is cool enough to touch with your hand. Remove filler cap slowly to relieve pressure. Cooling System Inhibitor contains alkali. Avoid contact with skin and eyes to prevent personal injury. |
 |
| NOTICE |
|---|
All water is corrosive at engine operating temperature. Use either Caterpillar Cooling System Inhibitor liquid, or the coolant conditioner element to treat either plain water or ethylene glycol solution. Do not add both the liquid cooling system inhibitor and the coolant conditioner element at the same time. |
| NOTICE |
|---|
When changing antifreeze solution, replace the maintenance filter element with the correct precharge element. |
| NOTICE |
|---|
The normal coolant conditioner element must not be used with Dowtherm 209 coolant. |
| NOTICE |
|---|
Excessive coolant conditioner (greater than the recommended 6% initial fill) together with concentrations of antifreeze greater than 65% cause deposits to form and may result in radiator tube blockage and overheating. |
When fresh engine coolant consisting of either plain water or water and antifreeze is installed, a precharge element should be installed for use until the first normal element change period.
- 1. Close inlet valve and outlet valve at element base. Turn clockwise to close both valves.
- 2. Remove the coolant conditioner element. Discard element.
- 3. Clean element mounting base. Make certain all of old element gasket material is removed.
- 4. Use the correct maintenance element for your cooling system. Maintenance elements are sized to the coolant system capacity.
- 5. Coat the seal of the element with a thin film of clean engine oil or antifreeze.
- 6. Install the element until seal contacts base, then tighten an additional 3/4 turn.
- 7. Open the inlet valve and outlet valve.
- 8. Start engine and check for leaks.
Coolant Level
Check the engine coolant daily with the engine stopped and cool.
- 1. Slowly turn the filler cap to the first stop to release pressure.
|
Be careful: If the engine is warm-steam may spray outward under high pressure. |
|
- 2. Push the cap down and turn until the cap is released.
- 3. Maintain coolant level to the base of the fill pipe.
- 4. Make-up coolant should be with water free as possible from scale forming minerals (not softened water) and a permanent type antifreeze containing rust inhibitor or a solution of water and Caterpillar Corrosion Inhibitor. Follow the recommendations given on the container.
Maintain a 3% concentration of Caterpillar Corrosion Inhibitor.
| NOTICE |
|---|
Do not use with Dowtherm 209. |
Make-up water added without the proper proportions of coolant corrosion inhibitor can cause excessive lime deposits and corrosion.
| NOTICE |
|---|
Add coolant slowly to a hot engine to prevent possible cracking or distorting the cylinder head. |
If a loss of coolant is noticeable, check for leaks in the system. After filling the system, start the engine and recheck the coolant level after normal operating temperature is reached. Running the engine at operating temperature will permit the temperature regulator to open and allow the coolant to circulate through the entire system and purge air from the engine.
If a permanent antifreeze solution is used in the cooling system, either renew the rust inhibitor every three months by adding Caterpillar Corrosion Inhibitor, or drain the entire cooling system annually and refill with fresh coolant solution.
Draining The Cooling System
To clean the cooling system or replace the coolant solution, it is necessary to completely drain the cooling system.
- 1. Stop the engine.
- 2. Slowly turn the pressure cap until the cap is removed.
|
Be careful. If the engine is warm-steam may spray outward under high pressure. |
|
- 3. Open the radiator drain valve.
- 4. Remove block and oil cooler drain plugs.
Draining Heat Exchanger Cooling System
- 1. Stop the engine.
- 2. Slowly turn the heat exchanger pressure cap to the first stop and release the pressure.
|
Be careful. If the engine is warm-steam may spray outward under high pressure. |
|
- 3. Push the cap down and turn until the cap is released.
- 4. Remove the drain plugs to drain tank, pump, block and lines.
- 5. If the ambient temperature is expected to go below freezing, drain the raw water line between the heat exchanger and the raw water pump.
RAW WATER PUMP DRAIN
Cleaning The Radiator (External):
Every 250 hours clean dirt and trash from between the tubes of the radiator which may cause excessively high operating temperature. Wash, brush or blow the dirt out with whichever method is available and most effective.
Cleaning The Cooling System (Internal):
Clean the cooling system periodically. Mineral deposits can cause serious engine damage by retarding the transfer of heat to the coolant. A deposit of lime 1/32 inch thick insulates the same amount as 2 inches of steel, reducing the heat transfer substantially. Loose scale and sediment deposited in the cooling system will reduce circulation, resulting in possible engine damage.
To clean, stop the engine when it is at normal operating temperature and drain as quickly as possible.
Flush thoroughly, then fill with a solution of one pound of Oxalic Acid or Sodium Bisulfate per five gallons of water. Run the engine at operating temperature one-half to one hour, then drain and flush until water is clear. Fill with a solution of one-half pound of Sal Soda per ten gallons of water and run the engine ten minutes. Drain, flush and fill with water, adding coolant conditioner and the desired amount of antifreeze.
Cooling System Pressure
A pressure relief cap on the radiator or expansion tank controls the pressure of the cooling system and prevents the loss of coolant through the radiator overflow tube.
Pressurizing the cooling system serves two purposes. First, it permits safe operation at coolant temperatures higher than the normal boiling point, providing a margin of cooling for intermittent peak loads. Secondly it prevents cavitation in the water pump, and reduces the possibility of air or steam pockets forming in the coolant passages. Proper operation of the pressure relief cap assembly is essential. A pressure relief cap allows pressure (and some water, if the cooling system is too full) to escape when the pressure in the cooling system exceeds the capacity of the pressure cap. Loss of pressure will cause steam to form when coolant temperature is above the normal boiling point.
The cooling system is designed to work under a pressure of 4-7 PSI (7 PSI is recommended) to allow a high heat transfer for size of radiator and fan combination. In a pressurized system, a leaking radiator cap allows loss of pressure and coolant. For a simple check of cooling system pressure, install a pressure gauge in the radiator top tank and pressurize the system. Do this by either using an air valve and external air supply, hand pump, or by operating the machine until the coolant reaches operating temperature. System pressure should rise to approximately 7 PSI, and any additional pressure should force air past the relief valve through the overflow opening. Do not allow pressure to exceed 10 PSI. The system should hold a minimum pressure of approximately 7 PSI, and a pressure must remain constant with the air supply shut off or the engine running at a constant temperature.
PRESSURIZING THE SYSTEM
If the pressure isn't maintained, overflow loss can occur as cooling system temperature rises. Do not remove the cap while the system is at operating temperature. Check coolant level only when cold.
If the system does not hold pressure, find the leak.
Carefully inspect the radiator cap, seals, sealing surfaces and the top tank filler neck surface for damage.
RADIATOR CAP
Testing The Temperature Gauge
Remember that boiling point temperature and pressure go hand-in-hand and neither one can be tested logically without considering the other. For example, the effect of pressurization and altitude on the boiling point of water is shown in the chart.
If overheating and loss of coolant is a problem, a pressure loss in the system could be the cause. If an overheating condition is indicated on the temperature gauge and loss of coolant is not evident, check the accuracy of the temperature gauge. Make this check by installing a thermometer with a suitable bushing into the cylinder head.
Start the engine. Partially cover the radiator to reduce air flow and cooling. The reading on the instrument panel gauge should agree with the reading on the thermometer.
|
Use CAUTION when working around moving parts with the engine running. |
|
CHECKING COOLANT TEMPERATURE WITH THERMOMETER
Temperature Regulators
There is a temperature regulator located at the front of each cylinder head.
The opening temperature of the regulator (bench test in antmospheric pressure) should be 180 ± 2°F (82 ± 2°C). The regulator should be fully open at approximately 197°F (92°C).
- 1. Remove the regulator from the housing.
- 2. Submerge the regulator and a thermometer in a pan of water as shown.
- 3. Apply heat to the pan and stir the water to maintain uniformity.
- 4. Observe the opening temperature of the regulator.
If the regulator does not operate correctly, install a new one.
Cooling System Hoses
Inspect all coolant hoses annually and replace if they show signs of cracking or leaking. Periodically replace all hoses, as it is many times difficult to determine the condition of a water hose by visual inspection and feel. Coolant hoses are expendable items and periodic replacement is considered good maintenance practice.
Air, Gases And Steam In The System
Incomplete or improper filling is a major cause of air in the cooling system. Also, leaks in various components such as the aftercooler, and hoses allow air to enter the cooling system, especially on the inlet side of the water pump.
Air in the system produces foaming or aeration and affects water pump performance. The air bubbles insulate various parts of the engine from the coolant, and hot spots form. As the air bubbles circulate or break up, coolant contacts the hot surfaces, creating steam. The steam pockets have basically the same effect as air bubbles, accelerating the formation of more steam. Consequently, coolant discharges through the overflow.
Exhaust gas leakage into the system causes similar conditions. Exhaust gas can enter through internal cracks or defective cylinder head gaskets.
Most of the causes can be checked by a visual inspection, while others require disassembly or a simple test.
Air in the cooling system is one cause of overheating which can be located by a simple test known as the "bottle test". The equipment required to perform such a test consists of a 1 pint bottle, a bucket of water, and a length of hose with an inside diameter large enough to fit over the end of the radiator overflow pipe.
To Test
Fill the cooling system to proper level. Wire open the relief valve in the radiator cap. Install the radiator cap and tighten. Assemble the rubber hose over the end of the overflow pipe.
Start the engine and operate it at high idle speed for at least five minutes after the engine reaches operating temperature. Block off part of the air flow through the radiator to maintain operating temperature. After the temperature has stabilized and all expansion air has vented out, place the loose end of the hose in the water filled bottle which is inverted in the bucket of water. If it takes less than a minute to displace the water in the pint bottle, leakage into the cooling system is excessive.
Loose precombustion chambers, faulty precombustion chamber seals, a loose cylinder head, or a damaged head gasket are possible causes of air in the cooling system. In any case, the cause should be corrected immediately.
Water Pump
The water pump circulates the coolant through the aftercooler and oil cooler, the cylinder block, cylinder head, and radiator. Poor coolant circulation causes overheating. A badly corroded or worn water pump impeller, or even a loose impeller, reduces circulation and efficiency.
Every 2000 hours inspect the water pump and rebuild as necessary, or install a rebuilt pump to reduce downtime to a minimum. Your authorized dealer is familiar with worn replacement limits and with disassembly and assembly procedures.
Raw Water Zinc Rods (Salt Water Only)
Salt water has a highly corrosive reaction with metal by a chemical action called "electrolysis". To prevent this chemical action taking place, with parts used in the raw water system, zinc plugs are placed in the raw water piping. Zinc is a relatively soft metal which reacts quite readily with the salt water. Thus, by the deterioration of the zinc, the raw water system parts are protected from corrosion.
The zinc rods must be inspected regularly and be replaced as they become deteriorated. The zinc rod plugs are painted red for easy identification.
Fan Belts
Examine the drive belts annually for wear and replace if they show signs of wear. Loose or worn pulley grooves cause belt slippage and low fan speed. If fan belts are too loose, they vibrate enough to cause unnecessary wear on the belts and pulleys and possibly slip enough to cause overheating.
If one belt in a set requires replacement, always install a new matched set of belts-never replace just the worn belt. If only the worn belt is replaced, the new belt will carry all the load-as it will not be stretched as much as the older belts-and all the belts will fail in rapid succession.
BELT TENSION
Adjustment:
Check new belts for adjustment after the first 10 hours and every 250 hours thereafter. To check belts-apply 25 lbs. (11.5 kg) force midway between pulleys. Correctly adjusted belts will deflect 1/2 inch (12.5 mm) to 3/4 inch (19 mm) for the first check. Maintain later adjustments at 7/8 inch (23 mm).
To Adjust:
Loosen the lockbolts on the fan pulley adjusting bracket and adjust fan pulley with the adjusting bolt. After belt tension is correct, tighten lockbolts.
Readjust alternator belt tension and tighten adjusting nuts.
Aftercooler
Some engines may be equipped with an aftercooler. The aftercooler is a simple device resembling a small radiator core. Water from the engine passes through the core tubes. Engine inlet air, warmed by the turbocharger compressor is directed through the core and around the tubes. Since the temperature of the water is lower than the air, the air is cooled as it leaves the aftercooler and becomes more dense as it enters the intake manifold. This means more air (oxygen) is available for combustion, resulting in more fuel being burned and more power produced.
One degree increase in inlet air temperature increases exhaust temperature approximately three degrees. Restrictions to either coolant or air flow reduce aftercooler efficiency and severly affect the engine and cooling system.
When engine is being rebuilt, remove the aftercooler and clean core, water and air passages.