When was the last time you bled the air out of your X1/9 radiator? If you find yourself asking what the heck I'm talking about then read on, this article is for you. Bleeding the radiator should be on your routine maintenance list along with changing the oil and washing the bugs off the nose. See Lalo's Tips below.

Remove the expansion tank cap and fill it to the top with your desired mixture of Ethylene-Glycol/Diethylene-Glycol/Disodium-Sebacate (Antifreeze or Coolant) and H2O, I use 50/50 (HINT: premix the Coolant and H20 in the bottle, then pour it in. This ensures an accurate mixture). This is necessary for maximum 'head' to push the air out of the radiator. Check to make sure the heater valve is on full open. This allows the water to flow thru the heater core. Open the hood of your X1/9 and pull back the front carpet (if your car has one) from the top of the radiator shroud. Just next to the diver's side hood hinge is a 1" dia hole in the radiator shroud that allows access to the bleed screw (Item 6 in the above Figure).

Using an 8mm allen wrench open the valve a couple if turns until you hear a slight hiss of air escaping. Keep the valve open until water spills out thru the bleed screw. Note that depending on how much air is in your radiator this may take a minute and may require you to top up the expansion tank at least one more time. Close the valve an tighten it, but don't get carried away, it only needs to be snug!

More Tips and a Couple of Myths:

Tip: Make sure the car is situated such that the bleed screw is on the 'uphill' side of the radiator. Remember that air moves uphill. This is best accomplished by driving the car onto your driveway nose first and slightly diagonal to the right.

Tip: Note that the topped up and open expansion tank creates a 'head' since it is higher than the bleed screw. It is this 'head' that pushes the air out. It is possible to bleed the radiator when the engine is at operating temperature by simply opening the bleed screw and not going through the above procedure. This is possible since at operating temperature the cooling system is pressurized. By opening the bleed screw under these conditions the system pressure has the same effect as the expansion tank being full and open. But use caution! The radiator, bleed screw, and water coming out will be hot!

Myth: Raising the nose of the car- The system is designed such that air in the system will be trapped in the radiator. Raising the nose would at best only allow any air that could be in the pipes under the car to flow to the radiator. This is not necessary since air would never be trapped in the pipes to begin with.

Myth: Engine must be running- The idea is that a running car would result in the water flowing thru the system and thus the air would flow to the radiator when the valve is opened. As mentioned above, any air in the system would already be trapped in the radiator, so having the engine running would be of no benefit.

**Lastly, ensure that you are using a Fiat issue expansion tank cap. This is critical for proper operation of your cooling system.

That's all there is to it!

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