GM Corsica/Beretta 1988-1996 Repair Guide

Cooling System


See Figures 1, 2 and 3

Never remove the radiator cap under any conditions while the engine is hot! Failure to follow these instructions could result in damage to the cooling system, engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the radiator, use extreme care whenever you are removing the radiator cap. Wait until the engine has cooled, then wrap a thick cloth around radiator cap and turn it slowly to the first stop. Step back while the pressure is released from the cooling system. When you are sure the pressure has been released, press down on the radiator cap (still have the cloth in position), turn and remove the cap.

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

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Fig. Fig. 2: Coolant protection can be easily checked using a float-type hydrometer

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Fig. Fig. 3: If possible, as hand-held pressure tester should be used at least once a year to check system integrity


For 1996 vehicles, when adding coolant, it is important that you use DEX-COOL®, an orange colored, silicate free coolant meeting GM specifications 6277M. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result.

The cooling system should be inspected, flushed and refilled with fresh coolant at least every 30,000 miles (48,000 km) or 24 months. If the coolant is left in the system too long, it loses its ability to prevent rust and corrosion.

When the coolant is being replaced, use a good quality antifreeze that is safe to be used with aluminum cooling system components. The ratio of antifreeze to water should always be a 50/50 mixture. This ratio will ensure the proper balance of cooling ability, corrosion protection and antifreeze protection. At this ratio, the antifreeze protection should be good to -34°F (-37°C). If greater antifreeze protection is needed, the ratio should not exceed 70% antifreeze to 30% water.


See Figures 4, 5 and 6

When checking the coolant level, the radiator cap need not be removed. Simply check the coolant level in the recovery bottle or surge tank.

Check the coolant level in the recovery bottle or surge tank, usually mounted on the inner fender. With the engine cold, the coolant level should be at the FULL COLD level. With the engine at normal operating temperature, the coolant level should be at the FULL HOT mark. Only add coolant to the recovery bottle or surge tank as necessary to bring the system up to a proper level.

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Fig. Fig. 4: Fluid level should be checked through the recovery bottle

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Fig. Fig. 5: If the coolant level is low, carefully remove the recovery bottle cap ...

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Fig. Fig. 6: ... then top off the cooling system using the proper amount and mix of coolant and water

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

On any vehicle that is not equipped with a coolant recovery bottle or surge tank, the level must be checked by removing the radiator cap. This should only be done when the cooling system has had time to sufficiently cool after the engine has been run. The coolant level should be within 2 in. (51mm) of the base of the radiator filler neck. If necessary, coolant can then be added directly to the radiator.


Checking the Radiator Cap Seal

See Figure 7

While you are checking the coolant level, check the radiator cap for a worn or cracked gasket. If the cap doesn't seal properly, fluid will be lost and the engine will overheat.

Worn caps should be replaced with a new one.

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Fig. Fig. 7: Be sure the rubber gasket on the radiator cap has a tight seal

Checking the Radiator for Debris

See Figures 8 and 9

Periodically clean any debris; leaves, paper, insects, etc. from the radiator fins. Pick the large pieces off by hand. The smaller pieces can be washed away with water pressure from a hose.

Carefully straighten any bent radiator fins with a pair of needle nose pliers. Be careful, the fins are very soft. Don't wiggle the fins back and forth too much. Straighten them once and try not move them again.

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Fig. Fig. 8: Periodically removal all debris from the radiator fins


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 i