Inside I flush the water heater, clean bath exhaust and rangehood fans, make sure all risers to sinks are braided stainless hoses (if not copper or solid), I put vinyl under sinks that runs up the back a bit, clean all filters & heaters and snake all sink and tub drains at least quickly with a $3 zip-it.  

connect it to building by the garden hose and its will be very useful for storage.

My best tenant used the outside hose to clean out the garbage can when it was freezing outside at 30degrees out.This caused the outside spigot pipe to burst that leads in the basement.

Replace battery is necessary.(9) Test/Reset GFCI receptacles.(10) Test outside hose bibs and main shutoff valve.(11) Visual inspection of ceiling for stains.(12) Replace burnt out light bulbs for elderly tenants with no ladder.Then every 6 month or so I would do a few additional things such as wash down AC compressor coil; open the tub drain and bathroom lav drain stopper and tease out the hair down there; may be do a test load of wash and dry if I have some dirty rags in the back of my vehicle; get on the roof for a visual check, open the main sewer cleanout outside and shine a flash light down, and obviously I emailed tenants before each visit to see if they need me to look at anything. 

It was like drinking from a fire hose... three days, 8+ hours per day.

One of the teenagers even stole their water hose and one our neighbors across the street noticed the section 8 tenants using the hose to water their grass.

Around here, the acid test on a septic field is the hydraulic load test...they put a specified volume of water (based on BR count because systems are sized/designed based on BRs) and measure the water level in the field following the specified input. 

My wife drives a 2009 and we have only had one problem with a radiator hose.

Like the plumber that tried to charge my landlord $700 for putting in a new faucet and a couple of short water hoses! 

Check the "obvious" stuff first... dishwasher drain hose not kinked or blocked.