johonole

Having a little problem bleeding my coolant system. Do you do it AC on or off, or does it matter?

ivangene

cant see how the AC would matter?

I have not done this at home, what is the prescibed method (at the shop we pull a vacuum on the system and them "suck" in fluid

Tom M

Shouldn't matter. The Boxster shop manual doesn't mention the A/C at all when flushing or bleeding air. It does mention making sure the heater is on when draining but doesn't mention it for bleeding. Though it probably is a good idea to make sure coolant is flowing everywhere that it can and I don't see any harm in having it on when bleeding air from the system

Shark Attack

just follow the instrctions on the can.. Thats what I did and my AC is now good to go. I bought a can with the little gauge on it also..

Shark Attack

Sorry.. mis-took your Coolant for refridgerant. My bad... never mind above post

Macster

Off. If the A/C is on the radiator fans run all the time and the coolant will not get as hot as it would otherwise.

When you hear the fans come on the coolant temperature is 212F (this number varies a bit depending upon the source) and when the fans go off the temperature has dropped to 205F.

You want to get the coolant hot to open up the t-stat as wide as possible to pump the coolant through the system with sufficient force to remove all the air pockets in the cooling system.

Sincerely,

Macster.