For 1990-2009 cars

### Hoses and Clamps Inspection Procedure

• | Inspect the condition of all hoses and clamps. Hoses should be flexible and show no signs of bulging.

• | Inspect the hoses for cracks, kinks, and areas of possible leaks.

• | Inspect the hose brackets, supports, ties and clamps.

• | TIghten and adjust the components as needed. (The spring clamps are not adjustable.)

### Radiator Cleaning

Notice: Do not spray cold water on a hot radiator.

Notice: The heat exchanger fins are necessary for good heat transfer. Do not brush the fins. This may cause damage to the fins, reducing heat transfer.

At least once a year, clean the front face of the radiator. On vehicles with air conditioning, clean the front face of the condenser. Remove any bugs, leaves, and other material by blowing compressed air from the rear of the radiator towards the front of the vehicle. If compressed air is not available, use a water hose to force water through the radiator from the rear toward the front of the vehicle. Use water only with the engine off and cool.

### Checking the Coolant

Caution: As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the pressure cap while the engine is hot and pressure is high will cause the solution to boil instantaneously -- possibly with explosive force -- spewing the solution over the engine, fenders and the person removing the cap.

Notice: When adding coolant, it is important that you use GM Goodwrench DEX-COOL™ coolant. If coolant other than DEX-COOL™ is added to the system, the engine coolant will require change sooner: at 50 000 km (30,000 miles) or 24 months.

If possible, first check the side of the coolant recovery reservoir to determine the level of the coolant. If unreadable, remove the reservoir cap to check the coolant level. Check the coolant in the recovery reservoir each time the hood is up and the engine coolant is cold. The coolant level should be near the COLD mark when the system is cold. At normal operating temperature, the coolant rises. Only add coolant to the recovery reservoir to raise the level to the COLD mark.

While draining the system, check the color of the coolant. If the coolant shows an unusual amount of oil sediment (gray, white, foamy appearance), engine oil may be leaking into the cooling system. A coating of oil inside the coolant passages cuts down the system efficiency and may cause the engine to overheat. Also, a leak in the cooling system may cause coolant to flow into the oil passages. This contaminates the lubricant and damages the engine. Check the oil condition and level, refer to General Information.

If the pressure in the cooling system is too low, or if the coolant does not contain ethylene glycol antifreeze, the coolant will boil without the TEMP indicator lamp coming on. Pure water could boil at 119°C (247°F) and the TEMP indicator lamp would not come on, even with a 124 kPa (18 psi) cooling system. Pure water lacks the necessary rust inhibitors and coolant pump lubrication. Unless work is being performed on the cooling system, do not operate the engine without the pressure cap, or with a loose cap. This will cause the coolant to boil before the TEMP indicator lamp comes on.

In order to check for the proper freeze protection, refer to Coolant Concentration Testing .