I bought a motorcraft compressor that came with the oil already in it, so is that all the oil the system needs?

 

Does the paperwork specify how many ounces of oil? The "precharged" amount can vary from 2-3 ounces of shipping oil to a full system charge of oil. It depends on the supplier.

If it has ~4 ounces, that's enough for a compressor replacement if nothing else was done to the system.

If it has ~8-10 ounces, that's a full system charge. If you haven't flushed the rest of the system, that will be WAY too much oil. If you HAVE flushed the system, that will be the correct amount.

EDIT: If this is for the 93 in your sig keep in mind that the truck may have originally come with mineral based oil (R12). If it was originally R134a it will have PAG oil. Be sure you have the correct oil.
1993 was the changeover year. Most Ford products came with R134a, but there are some early 1993 vehicles that had R12. Some models were switched mid-year.

 

lsrx101, you just solved all of my a/c problems. I asked a guy (that is supposed to know a lot about a/c) how much oil to put in the system. He told me to put 9 oz in the compressor, 3-4 oz in the condenser, 2 oz in the drier and 2 oz in the evaporator. That is what I have been doing with no luck at all. After reading your post, I flushed everything out and installed the pre charged compressor without adding anymore oil and what do you know the darn thing is nice and cold now.
I did look at the instructions for the compressor where I found that it is a 134a only compressor, so it does have the correct oil in it, thanks for bringing that point up.
I guess I won't be going to him anymore for a/c advise, he sucks. I am glad that he retired, I would hate to think people were paying him to do that to there vehicles.

Thanks for the help

 

I'm glad you found the info useful.
Yes, too much oil can cause all sorts of problems. Getting the proper amount into the system can be tricky, as there is no dip stick. That's why it is usually recommended to flush the system and start with a known amount (just like you chose to do). It eliminates the guess work.
Good Job!

BTW,You didn't flush the accumulator, did you?

 

I replaced the accumulator and the orifice tube.

 

.................Good boy!

 

Good Job Sir!

 

YES. that is all the oil it needs.