986 Forum - The Community for Porsche Boxster & Cayman Owners - AirLift won't hold vacuum on drained system.

Quote:

Originally Posted by antny (Post 443731)

So I am about to do my water pump and thermostat because the car is running a little hot. The car is fine if I run the ac and the fans kick on and the temp does not climb. If I do not have the ac on and the fans are not running it will climb slowly. My coolant level is fine so I ordered a uview and hooked it up tonight to check the system on a vacuum. So my question is what size compressor are you guys using? I borrowed my in laws compressor and it is a 3 gallon and is pressurized at 100 PSI to start. Once the air starts flowing it will get to 25 psi of vacuum but at that point the air compressor kicks on and jumps back down to 20-18 PSI and will flicker. My system does have fluid in it still. Do I need a bigger compressor that will hold the PSI more or do I close the valve as soon as it hits 25 psi and wait to see if it holds the vacuum?

Thanks!

If your compressor can't pull the desired level of vacuum all the way up in one shot then you can do it in two stages: Run the compressor until it fills, and then open the UView valve. When the compressor is getting empty and it kicks on close the valve on the UView end and wait for the compressor to fill and shut off, and then open the valve on the uView end again. Then once the vacuum gets to 25 close the UView valve again.