Deciding ! Keep rental or sell ?

[Brendan Quinn]

I have an investment thats been stable. has not required much upkeep

two years iv owned it without much difficulty finding renters hvac, roof without issues so far but are on the back end of expected life.  House 2004. 
im trying to decide if it makes sense to keep it  or lose it now before big expenses. Cash flow of 300 a month without considering vacany or the expenses of inevitable maintenance.  

Feels like its smart to sell because if i pay for a new roof or hvac my cash flow will take a long time to get me even on that out of pocket.  Selling seems right but i took depreciation on the property, so im wondering the best strategy here