Hi Folks,

I know that a large number of you are air-cooled types, so please ignore this thread.

If you are knowledgeable about liquid cooling, I have a question for you: How do you get air bubbles out of the system?

I have areas in my cooling system that are above the pump, but below the coolant reservoir. I'm pretty sure I have air in that area (it is where I have my motor controller - the car is now electric but uses liquid cooling)...

I was thinking of putting a T in next to the controller, and then a valve or cap on that T to let the air out.

Experts? Liquid cooling fanatics?

Cheers,
Peter

Put the bleed valve at the highest spot in your cooling system to bleed out the air.

I use a vacuum pump and holding tank.

Completely seal the cooling system except 1 hose to the holding tank. Fill the holding tank 1/2 with water. Pull vacuum through the tank. The air will compress and get sucked from the system. I use clear hose to see the air and water. My tank has fittings on top and bottom. The top goes to the vacuum pump. The bottom back to your highest vent on the cooling system. Pull vacuum for a couple hours. When your done, remove vacuum pump. Water will draw back into cooling system from the tank. Done. You may have to repeat a few times but it will work perfect.

You can get the tank (portable air tank) and vacuum pump from harbor freight for less than $100. just drill and tap the tank for fittings. Add some ball valves. Do not use for compressed air after. Only vacuum!!!

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a converted 914 with water cooling may have more than one high spot, so multible bleeders might be required.

My 914 had that issue.

one other thing you can do is raise up one end of the car very high and that can help bleeding. i was forced to do a road side radiator repair once, and ended up pushing the car up a step drive way ramp, to help burp the air out, must have been over 35 degree tilt.

one other solution is that VW vanagon folks do, they build a Libby Bong (do a search for that term on "The Samba" website.) I made one for my van and it worked great. It is basically a PVC pipe that clamps via a rubber collar to the coolant tank, you fill it up and since it is so tall, it provides lots of head pressure and will force the air out of the system.

the Libby Bong is probably your best solution.

If you have the libby bong in your car, if you get stopped by the police, be prepared to do some fast talking!!!!!