It doesn't hurt to get a can of Refrigerant oil and add that as well.
Make sure it is Synthetic Oil for R134a Refrigerant.
It is usually a very small can, a little bigger than your palm.
It will inject the right amount of oil for your AC system.
Do this FIRST, before adding any refrigerant.
As your system leaks the R134a, you also lose the Synthetic Oil
that lubricates the internal parts of the AC Compressor.
