What is the Air Bleed Housing Assembly all about?

Coolant is essential to engine operation throughout the year. It carries away heat that would otherwise kill the engine during operation, but it also protects against freezing during winter – normal water can freeze solid inside an engine, causing immense damage from expansion. However, coolant degrades over time and must be changed. Changing the coolant allows air into the system, which must be removed in order for the engine to operate correctly. Air in the coolant lines can cause many problems, including overheating and severe engine damage.

The air bleed housing assembly, or air bleeder housing assembly if you prefer, is a simple setup generally found near the back of the engine that allows you to combat this problem. It is usually the highest point on the cooling system. It’s nothing more than a small housing with a bleeder nut attached. By opening the valve while the engine is running after a coolant change, air escapes out of the system and prevents overheating.

Keep in mind:

• The air bleed housing assembly is not inspected during normal maintenance, but should be inspected during any coolant system service.
• The air bleed housing assembly is made of metal, and running straight water in your system can cause problems including rust and corrosion that will require the assembly to be replaced.

How it's done:

• The air bleed housing assembly is verified to see if it needs to be replaced
• The defective air bleed housing assembly is removed
• The new air bleed housing assembly is installed
• The air bleed housing assembly is tested for operation and leaks
• The vehicle is tested to ensure proper operation of the air bleed housing assembly

Our recommendation:

The air bleed housing assembly on your car’s coolant system is crucial after a coolant system change. If air is not removed from the lines, the engine could overheat from an airlock, causing damage as serious as a cracked block in extreme situations. Have the air bleeder housing assembly replaced by one of our expert mechanics if it is corroded or inoperable.

What common symptoms indicate you may need to replace the Air Bleed Housing Assembly?

• Bleeder valve will not open
• Bleeder valve or assembly is damaged in some way that compromises operation
• The housing is leaking coolant.

How important is this service?

While the air bleed housing assembly isn’t critical to normal operation, it’s a crucial part of your engine coolant system. If the bleeder valve is damaged, or the assembly is corroded, we recommend replacing it as soon as possible. It will not prevent you from driving your car, but it can cause serious issues after a coolant change.