[Louwie]

I bought a split air conditioner the one that have the quick connecters, is it necessary to suck vacuum on this systems and if I did not suck vacuum what can happen with the system.

[smoothy]

It won't work very well if you don't. Because air doesn't behave like refridgerant and will displace refridgerant.

[Grady White]

Is this a new system or used? If new & the line set is sealed on both ends with what looks like aluminum foil, you do not need, nor do you want to pull a vacuum. The line set is precharged with refrigerant which will release into the evaporator when you make up the connections.

[smoothy]

I agree with what Grady just said... if this is the case.