How to re-evaluate a property you already own?

[Rusty Williams]

Background: My brother and I have 4 rental units currently.  Unit 1 and Unit 2 are on a 15 year note and barely cash flow.  Unit 2 is in an area that doesn't really fit with what we invest in and we are currently selling it (closing should be next week).  The property will not appreciate much over time and my brother (the handy man of us) has moved an hour away, so we will start to look for properties where he is soon.  

The selling of unit #2 has cause me to reconsider selling unit number 1.  

How would you re-evaluate a property?  
Would you run the numbers asking yourself would you buy it again right now?  
How would you do it?

Thanks in advance for any advice or insight!

Rusty