How to Replace Coolant

The old anti-freeze will rust and corrode the coolant system of the vehicle if not replaced with intervals. With time, the anti-freeze acid content increases and clogs the radiator and coolant passageways damaging the gaskets and water pump. This will make the engine suffer from high temperatures, leakages and insufficient performance of the cooling system. To avoid engine problems including overheating and freeze-ups, changing anti-freeze regularly is an important part of defensive maintenance and it keeps the vehicles performing at its most favorable levels. This article will guide you to replace a coolant system in a DIY style, follow the simple directions to keep the coolant system functioning properly for a longer time.

Things Needed

  • Rag
  • Drain pan
  • Garden hose

Replace Coolant


Step 1:

Before starting the task, make sure that the engine is sufficiently cool. Pull the hand brake and open the bonnet.

Step 2:

Take off the radiator cap and check the coolant by rubbing your finger in the anti-freeze mixture. Check if there is any presence oil, rust and foreign matter. If any such presence is found then the cooling system needs to be properly flushed and cleaned.

Step 3:

Inspect the clamps and radiator hoses for any possible leaks. Replace or repair as necessary the anti-freeze has drained from the system.

Step 4:

Find the drain valve under the radiator.

Step 5:

The drain pan has to be placed on the groud under the drain valve of cooling system. Loosen the drain valve and take off the radiator cap.

Step 6:

Allow the coolant mixture to drain from the system. If the engine block is fitted with a bleed screw or a cooling drain plug, then place the drain pan under the plug and take it out.

Step 7:

When the coolant has stops draining from the engine block, remove the drain pan from under the car.

Step 8:

Now, run water through the cooling system by placing a garden hose on the radiator neck. Continue to flow water until clear water is seen coming out from the radiator, engine drain plug and valve.

Step 9:

Allow the water to drain out from the cooling system and then the radiator, engine drain valve and plug have to be tightened.

Step 10:

Use the equal amount of new anti-freeze and clean water to refill the cooling system. Fill it up to the radiator neck.

Step 11:

Now turn on the engine and leave it stand idle for couple of minutes till the thermostat opens. Inspect the coolant level and it should be made sure that it is filled with new coolant mixture (anti-freeze and water) up to the ‘Full Hot’ mark. In case there is no reservoir container in the vehicle, allow the engine to cool down, take off the radiator cap and use the new coolant to fill the system. The level should be almost one inch below the bottom of radiator neck. Keep checking until a correct level is maintained.

Tips and Precautions

  • The anti-freeze has to be replaced after every two years. It is essential for better functioning of engine coolant.
  • The can be damaged by anti-freeze. Any spills of anti-freeze on the body of the car should be immediately cleaned with a clean rag.
  • Anti-freeze should be stored and locked away from kids. The used antifreeze should be disposed properly
  • The cooling system capacity for your particular car will be specified in the vehicle service manual besides locating the components. Many auto parts stores sell vehicle service manual or it can also be consulted from public libraries for free.

Further Readings: