Schwaben Coolant Vacuum Refill + Air Purge Tool | Cooling Test and Refill Tool Review | Audi VW

I explain the venturi effect that creates vacuum, assemble and install the tool, then demo a DIY cooling system test and complete the coolant fill. This air evacuation and purge tool from Schwaben will work on almost any vehicles radiator fill spout or expansion tank hole by using one of the many adapters, but I use it on my 2007 Audi A4.

Key moments:
00:00 - Tool overview
01:44 - How the venturi effect works
03:13 - Tool setup
05:36 - Drawing the vacuum
09:08 - Refilling coolant

The air source applied to the venturi adapter creates vacuum and draws as much air out of the (closed, hopefully) system as possible. The vacuum is held until the coolant source is opened which then fills the voids - regardless of direction of travel of the liquid; gravity doesn't matter now! The result should be that your engines cooling system is completely filled with coolant and there are no pesky air pockets in hoses, cores - anywhere.

I made use of the smallest, 35mm adapter neck for seating the vacuum gauge assembly into the expansion tank and after attaching my air source, do a simple leak test on the cooling system by drawing a -23 inHg vacuum and holding it for 2 minutes. Knowing that the coolant wouldn't leak out once it fills the system, I'm able to use the vacuum and fill the remaining capacity (total capacity of the 2.0L is 7.6L) of my car with the 50/50 premixed coolant I prepared.

With the maximum amount of coolant refilled into the system, it's only a matter of running the car with the temperature controls set to high and a moderate/low fan speed to allow the vehicle to warm up and have all passages (namely, any managed by the thermostat or heater core valves) flowing freely.

If the process is successful, your cars cooling system is free of air, the heather is blowing hot air easily, the the vehicle is able to manage it's temperature as the factory systems intended.

There are many brands that offer a tool like this, the notable ones being Airlift and Mityvac and all use the same principles, just with different quality of components and price tags. This Schwaben kit was purchased from ECS Tuning.