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Anti Freeze Flush

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2011 Boxster S




In the above video it states to first drain all coolant from the system before proceeding. A few questions are below.


  1.  What is the best way to drain the coolant on a Boxster?
  2. Can I do this with a 6 gallon Porter Cable Pancake Compressor? What should I set the pressure to? Or turn the compressor off and just use 6 gallon air volume in tank?
  3. How much anti freeze should i mix up in a 5 gallon bucket?  
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Remove the coolant drain plug near the thermostat housing (you will need a new crush washer for it).


Disconnect the hose going from the thermostat housing to the front of the car.  Realistically, unless you are going to refill the car with water, run it, and re drain it a couple of times, you are only going to get 80-85% of the old coolant out.


You are going to need a minimum of 90 PSIG sustained air pressure to correctly run one of these vacuum fill systems.


Your recharge mix should be a 50/50 mix of fresh coolant (we only use Porsche's stuff) and distilled water (about $1 a gallon at the supermarket); never use tap water.  In a 5 gallon bucket, you can comfortably mix 2 gallon each of coolant and distilled water.

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Thank you JFP for your detailed reply. 


Looking at the Bentley Service Manual I should be able to remove the splash shield, remove the drain plug and drain the coolant by supporting the car on jack stands in my garage. However, I'm not sure my compressor is going to have enough capacity to maintain 90 psi.  Was wondering if anyone could comment if they used a 6 gallon compressor like mine to change the antifreeze? 

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Yes, you'll be fine.  I use the UView Airlift system and have a small compressor of  3 gallons.  The key is it must be able to reach about 100 or so psi.   I run the compressor until the pressure starts to drop, then turn off the venturi vacuum valve and allow the compressor to recharge.  I repeat several times until my UView gauge is in the green or about 24-26 inches.  Then once charged make the switch to add the coolant.  I've filled about 10 cars with my small compressor. 


I pre-mix the anti-freeze in a five gallon bucket.  I agree with JP and only mix 4 gallons.  2 of antifreeze and 2 of distilled water.  The plastic tubing used as the fill tube will want to curl up so I zip tie it to something to hold it down in the bucket. And depending on how much old coolant you where able to remove, you may have to tip the bucket and place the fill tube correctly to get only new coolant out of the bucket and no air. 


You can find more about UView via YouTube by pressing  HERE: or on Amazon by pressing  HERE:








Using the ULead Airlift 5500 on MY98


Edited by kbrandsma
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