Draining your Radiator Fluid

Modern vehicle maintenance requires periodic coolant replacement. The reason for this is that the car’s cooling system is comprised of dissimilar metals. When you have dissimilar metals, the car’s cooling system is subject to corrosion, usually attributed to aluminum parts. To prevent this, coolant has anticorrosive properties and those properties wear off with time. Take a look at these steps so you can replace the coolant in your radiator.

Directions

1

Start by Purchasing New Coolant

It’s best to already have coolant on hand when you set to changing out your old coolant. Check your owner’s manual to determine the number of gallons required in the cooling system. You can buy undiluted coolant that you will later mix with water for a 50/50 mix, or you can purchase pre-mixed coolant. You can acquire this coolant at your local auto parts store, although plenty of convenience stores and supermarkets also have it in stock.

2

Have a Catch Pan Available

Make sure you have a catch pan available to receive the draining coolant. Later, you will need to transfer it into gallon containers so that you can dispose of it at the auto parts store. Another option, if your city permits, it is to drain it down the city sewer system. This is not always permitted, so be sure to check your waste management department in your city so you are not fined.

3

Prepare your Vehicle

Make sure your car is parked in an area where you can work around it easily. The car should be parked in place for at least an hour before you plan on working (or overnight, if possible), as your coolant should not be hot when you are working on it. Also, make sure the hood is up and the engine is cool.

4

Remove the Radiator Cap

Moving underneath your vehicle, with the catch pan easily accessible, loosen the radiator drain plug. It’s either located at the bottom of the radiator, or if the radiator has side-tanks, it will be near the bottom of one of the side-tanks. There are different styles of drain plugs, some of which are opened by fingers and some are opened by a Phillips-head screwdriver, so make sure you have a screwdriver with you if you do not know which type of plug you have.

5

Remove the Lower Radiator Hose, if Necessary

If you cannot locate the drain plug, if the drain plug is inaccessible, or if your radiator does not have a drain plug, another option is to loosen and remove the lower radiator hose. If you take this route, it will flood out, so do the best you can to aim it into the catch pan.

6

Allow Fluid to Drain

Allow used fluid to drain. This may require tightening the plug, draining the filled catch pan into the gallon container, and returning for another fill. This may happen several times, depending on coolant system capacity.

7

Use a Cooling System Flush

If it’s been a long time since you’ve maintained your cooling system, you may have some corrosive build-up. You may want to purchase a cooling system flush, available at your local auto parts store, that will break down this build-up so your system is restored to its expected performance. Check the instructions on the bottle of flush so you know the best way to use it with your vehicle, as different flushes may be administered differently.

8

Refill the System

The cooling system should be 95 percent emptied of any coolant (there are little areas of the engine that cannot be completely drained). Tighten the drain plug or replace the radiator hose, depending on your method of drainage, and add your new coolant. Again, double-check the quantity requirement as instructed in the user manual. Add either pre-dilluted coolant or the coolant/water mixture.

9

Tighten the Radiator Cap

Some cars have a special bleed-screw at the top of the head or the top of the intake manifold to bleed air from the cooling system. Not all do, so it is best to check your owner’s manual to see if yours is one of these systems. If you don’t, restart your engine and check for leaks. If you do, start your engine and follow manufacturer’s recommended bleeding procedures so there is no air in your cooling system.

10

Warm your Engine

Allow the engine to warm up to normal operating temperatures and check for leaks. Later that day or the next, after the engine is cool again, check the coolant level. If it’s low, it needs to be topped off with coolant.

All liquid-cooled vehicles need to change coolant periodically. You should be changing your coolant about every three years, so it doesn’t need to be done as often as changing your oil. Be sure you have checked your manufacturer’s manual before you go through these steps as some models require a specific kind of long-lasting coolant that you can only get through the dealership. For most vehicles, however, these steps will come in handy if you want to do it yourself and save some money by not going to a mechanic.