Replaced the 3 - way valve, is there a way to check the valve to see if it was bad?

blow in it from each direction, with your finger over one end, should allow air to go thru from the end that didn't have a hose on it

I did that and the larger holes the air goes thru no problem but the smaller hole , I think it might be were the oil line gets hooked to doesn't flow thru. I check the old and new ones the same way and they seem the same. I wish I knew how to post a picture of it.

close one end that the oil line goes thru with your finger, blow thru the end that didn't have a hose hooked to it, air should go thur

Spare, it has three hole outlets one small one that I think is hooked to the oil and two larger hole outlets
The larger outlets / hole air flows thru no problem
The smaller outlet/hole that the oil hose goes to has no air flow at all even when I close one larger hole and blow nothing goes thru the smaller one
Is that good?
I don't understand what the oil outlet hole does? If no air flows thru than how does the oil flow thru? I guess that's why you mechanics get the big bucks, I would love to learn how it all works but I'm retired now and just want to fix what I have.