Hi,

I need some advice, there was a break-in attempt to a shop where the burglars knocked off the outside unit of a small air con.
The owner didn't even find it out until he switched it on and it wasn't working. I made new pipe connections and regassed the system but it doesn't work. No matter how much gas I put inside, the suction pressure stays under 0bar and no cooling happens (after a while the unit cuts off with a big whoosh, I think it must be some safety pressure cut-off)
I think the unit sucked up some dirt and its blocking the expansion device. The question is, if I take it apart and unblock it, it might still have some particles inside, not even mentioning that it was running for a while without the pipes connected to it, sucking up a lot of air, dust and dirt, so how can I effectively clean the system up? Is there any recommended procedure or special filters I have to install? Is the compressor needs new oil?

It is a small toshiba 2.5kw inverter run on R410a.