If you Have the proper fittings and hose , no big deal.

The major concern is allowing anything other than "134"
to enter the system.

The following operation is illegal and harmful to the Planet.!

Without barrier hoses that contain the refrigerant, SOME
people "bleed" the refrigerant at the line connection to
insure no moisture or O2 can enter the system.

BUT,

YOU have (what you think is a leak) . Find and fix the problem.

It may be simple and cheap.