What is an air bleed housing assembly?
The air bleed housing assembly is responsible for removing air bubbles trapped in the cooling system. Air bubbles prevent coolant from cycling through the engine block properly, leading to overheating issues.
The air bleed housing assembly typically sits at the highest point of the cooling system. As air rises, it collects beneath the assembly. Many modern air bleed housing assemblies are designed to purge air passively as it collects beneath the assembly.
Older systems have bleeder screws mounted on top of the assembly—when you crack the bleeder valve, the air escapes the system, helping maintain proper coolant circulation.
When should I replace the air bleed housing assembly on my car?
There is no set replacement schedule for the air bleed housing assembly. That means you should only replace yours when it fails. Here are the most common signs of a bad air bleed housing assembly:
Engine overheating: If the air bleed housing assembly can’t release air bubbles, the cooling system may be unable to circulate coolant properly to maintain the optimum operating temperature. This can lead to engine overheating issues.
Coolant leaks: Coolant leaks are a common sign of a faulty air bleed housing assembly.
Strange sounds: If you hear bubbling or gurgling sounds coming from the cooling system, it could be a sign that air is trapped inside.
Erratic temperature gauge: If your dashboard temperature gauge is bouncing back and forth, it may be a sign that the air bleed housing assembly is malfunctioning.
Coolant discoloration: Air can cause the coolant to appear milky or frothy. If you notice your coolant looks strange, it could be a sign of a bad air bleed housing assembly.
Reduced heater performance: Air bubbles in the coolant can affect the heater core’s performance. If you notice that your car’s heater doesn’t work as well as it used to, it may be a sign of a faulty air bleed housing assembly.
Keep in mind: Many of these issues can point to other problems with the cooling system, like a faulty water pump, cracked radiator hoses, or a low coolant level in the coolant reservoir.
How often should I replace my air bleed housing assembly?
The air bleed housing assembly doesn’t typically require maintenance or service, and there is no set replacement schedule for it. That means that you’ll only need to replace yours if it malfunctions.
But due to its location and purpose, it’s unlikely that the average driver will notice the air bleed housing assembly is faulty. Typically, a mechanic will discover the problem during a routine radiator service. Because of that, it’s extremely important to maintain your cooling system
and keep up with regular maintenance. Can I replace my air bleed housing assembly myself?
An air bleed housing replacement can be a solid DIY project—if you have the right know-how and tools.
This is typically considered a mid-level job, requiring basic mechanical skills and knowledge of automotive cooling systems. Moderately experienced home mechanics should be able to replace the coolant air bleeder with relative ease, but novices may struggle.
If you’re not confident in your automotive repair skills, you should reach out to a professional mechanic.