You don't need to open the system so you don't need the vacuum pump at all?
Originally Posted by Peztoy
If the system has valves and ports in the right locations....
use a recovery machine to pump the condenser into the receiver, stop at about 2 psi. Braze the leak. Open the valves. Top up the system. Hand them a bill.
No vacuum pump needed, and down time of less than an hour.
I've fixed leaky condensers a few times like this, and evaps dozens of times (those are really easy since you can use the compressor to pump down.