Nissan/Datsun 200SX/510/610/710/810/Maxima 1973-1984 Repair Guide

Cooling System



The cooling fluid or antifreeze, should be changed every 30,000 miles or 24 months. When replacing the fluid, use a mixture of 50% water and 50% ethylene glycol antifreeze.

Check the freezing protection rating at least once a year, preferably just before the winter sets in. This can be done with an antifreeze tester (most service stations will have one on hand and will probably check it for you, if not, they are available at an auto parts store). Maintain a protection rating of at least -20°F (-29°C) to prevent engine damage as a result of freezing and to assure the proper engine operating temperature.

It is also a good idea to have the cooling system checked for leaks. A pressure test gauge is available to perform such a task. Checking and repairing a coolant leak in the early stages will save time and money.


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Fig. Fig. 1 Cutaway view of a typical cooling system flow

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Fig. Fig. 2 Check and add coolant, if necessary, at the coolant recovery reservoir

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Fig. Fig. 3 Use a funnel when adding coolant to avoid spillage

Check the coolant level every 3,000 miles or once a month. In hot weather operation, it may be a good idea to check the level once a week. Check for loose connections and signs of deterioration of the coolant hoses. Maintain the coolant level 3 / 4 -1 1 / 4 " below the level of the filler neck when the engine is cold. If the engine is equipped with a coolant recovery bottle check the coolant level in the bottle when the engine is cold, the level should be up to the MAX mark. If the bottle is empty, check the level in the radiator and refill as necessary, then fill the bottle up to the MAX level.

Never remove the radiator cap when the vehicle is hot or overheated. Wait until it has cooled. Place a thick cloth over the radiator cap to shield yourself from the heat and turn the radiator cap, SLIGHTLY, until the sound of escaping pressure can be heard. DO NOT turn any more; allow the pressure to release gradually. When no more pressure can be heard escaping, remove the cap with the heavy cloth, CAUTIOUSLY.

Never add cold water to an overheated engine while the engine is not running.

After filling the radiator, run the engine until it reaches normal operating temperature, to make sure that the thermostat has opened and all the air is bled from the system.


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Fig. Fig. 4 If there is no petcock, loosen the lowest radiator hose to drain the fluid

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Fig. Fig. 5 Remove the radiator cap to fill the system

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Fig. Fig. 6 Using a funnel, fill the system with the correct mixture and quantity of coolant

To drain the cooling system, allow the engine to cool down BEFORE ATTEMPTING TO REMOVE THE RADIATOR CAP. Then turn the cap until it hisses. Wait until all pressure is off the cap before removing it completely.

To avoid burns and scalding, always handle a warm radiator cap with a heavy rag.

  1. At the dash, set the heater TEMP control lever to the fully HOT position. If the vehicle is equipped with automatic air conditioning turn ignition switch ON and set temperature at MAXIMUM. Then turn the ignition switch OFF.
  3. With the radiator cap removed, drain the radiator by loosening the petcock at the bottom of the radiator.

When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Close the petcock. Be careful not to damage the petcock when closing.
  3. Refill the system with a 50/50 mix of ethylene glycol or other suitable antifreeze; fill the system to 3 / 4 -1 1 / 4 " from the bottom of the filler neck. Reinstall the radiator cap.

If equipped with a fluid reservoir tank, fill the reservoir tank up to the MAX level.

  1. Operate the engine at 2,000 rpm for a few minutes and check the system for signs of leaks and for the correct level.


To flush the system you must first, drain the cooling system but do not close the petcock valve on the bottom of the radiator. You can insert a garden hose, in the filler neck, turn the water pressure on moderately then start the engine. After about 10 minutes or less the water coming out of the bottom of the radiator should be clear. Shut off the engine and water supply, allow the radiator to drain, then refill and bleed the system as necessary.

DO NOT allow the engine to overheat. The supply of water going in the top must be equal in amount to the water draining from the bottom, this way the radiator will always be full when the engine is running.

Usually flushing the radiator using water is all that is necessary to maintain the proper condition in the cooling system.

Radiator flush is the only cleaning agent that can be used to clean the internal portion of the radiator. Radiator flush can be purchased at any auto supply store. Follow the directions on the label.