AC leaked all R-22 will 407c work without any conversion

Hello everyone

I am newbie here and i hope i can get some guidance

I have a 4 ton goodman ac unit model ckl42-10 which uses r22

Yesterday my ac unit developed a leak which caused all the r22 that was inside the system to leak and my ac unit is completely out of charge. I was able to find the source of the leak and had it repaired / soldered and did a vacuum to make sure all is good.

My question is as follows

Since my system is completely out of r22 do i need to change the mineral oil to poe oil before i use r-407c to charge the system or must the oil be removed and changed to poe oil before using r-407 instead of the old r-22


a family friend (hvac tech ) that came out yesterday to my place mentioned that since the system is empty then i can go ahead and charge it directly with 407c without an oil change is this correct

But im reading online that 407c refrigerant doesn't mix well with mineral oil which my cause they system to sludge however i am not sure how accurate this is.

Any help is greatly appreciated and thanks for your time and opinions

source https://hvac-talk.com/vbb/threads/2238631-AC-leaked-all-R-22-will-407c-work-without-any-conversion?goto=newpost