Isuzu Cars and Trucks 1981-1991




When adding or changing the fluid in the system, create a 50/50 mixture of high quality ethylene glycol antifreeze and water.


The fluid level may be checked by observing the fluid level marks of the recovery tank, if so equipped. The level should be below the "MIN" mark when the system is cold. At normal operating temperatures, the level should be between the "MIN" and the "MAX" marks. Only add coolant to bring the level to the "MAX" mark.

If the system is not equipped with a recovery tank, allow the engine to cool down before opening the radiator cap. Open the cap and add coolant to bring the level to about 13mm ( 1 / 2 in.) below the filler neck.

Should it be necessary to remove the radiator cap, make sure that the system has had time to cool, reducing the internal pressure.

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Fig. Coolant recovery tank fill to the MAX mark when hot


The cooling system should be drained, thoroughly flushed and refilled at least every 30,000 miles or 24 months. These operations should be done with the engine cold.

  1. Remove the radiator and recovery tank caps. Run the engine until the upper radiator hose gets hot. This means that the thermostat is open and the coolant is flowing through the system.
  3. Turn the engine "OFF" and place a large container under the radiator. Open the drain valve at the bottom of the radiator. Open the block drain plugs to speed up the draining process, if so equipped.
  5. Close the drain valves and add water until the system is full. Repeat the draining and filling process several times, until the liquid is nearly colorless.
  7. After the last draining, fill the system with a 50/50 mixture of ethylene glycol and water. Run the engine until the system is hot and add coolant, if necessary. Replace the caps and check for any leaks.

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Fig. Radiator drain plug