Of course, changing the oil is one of the items of Preventive Maintenance authorized for accomplishment by the holder of a Private Pilot's certificate under 14 CFR 43 Appendix A Section (c).
To change the oil in a Cessna 182 the following items are essential:
- 10 quarts of oil;
- An oil filter;
- An oil analysis kit;
- Safety wire (the 0.032" flavor);
- Safety wire pliers;
- A couple of small nylon cable ties ("Ty-raps");
- A torque wrench with a 1" socket;
- A 5 gallon pail;
- The usual array of basic tools;
- A helper (to wrangle the lower cowl).
The third item is up there in the darkness beyond the cowl flap. The air inlet duct from the air filter is secured to the carburetor inlet air box on each side by a 1/4-turn fastener. If you are fortunate they will be "wing-nut" sorts of an animals and you can reach way up there and separate them manually. If you are not so fortunate you may have to engage them with an appropriate screwdriver, which is more difficult and requires more colorful language.
Once all three connections are disconnected you can unfasten the 1/4-turn Cleco fasteners that secure the lower cowl in place (taking care not to forget the two that are way down at the bottom just to the left and right of the nose gear strut) and carefully lower the cowl clear of the exhaust pipe and carry it away. (This is where your helper earns his keep.)
I unscrew the filter as quickly as possible, keeping a roll of paper towel handy.
Once the filter has been detached and extracted and the area has been cleaned up, untwist and remove any left-over safety wire that may still be hanging from the filter adapter. Then, take a good look at the filter adapter. There is an Airworthiness Directive, AD 96-12-22, that applies to Cessna 182 aircraft. It requires inspection of the oil filter adapter at every oil change and in particular focuses on the integrity of the torque putty applied to the joint at the base of the adapter. (If the putty is broken it indicates that the filter adapter is not secure.) This is one of the few inspections that can be accomplished by a Private Pilot, and it has to be logged in the airplane's maintenance records.
The oil has been draining for a few minutes by this time so it's a good opportunity to capture a small sample of the used oil to send off for spectrometric analysis. I use the kits provided by Aviation Laboratories of Houston, Texas. They provide very nice on-line reports of their analytical results.Dow-Corning DC-4 silicone grease (or, if you are fresh out of DC-4, a film of clean engine oil). Use your calibrated torque wrench (as shown above) to tighten the filter to a torque of 16-18 ft. lbs.
With the oil in the engine, pull the airplane out of the hangar and start it up. Watch the oil pressure closely, and if the gage doesn't respond in a few seconds, shut down and find out why not. Don't run the engine too long, as it's un-cowled and therefore isn't being cooled properly. After a couple of minutes shut down and inspect the engine for any evidence of leaks.
If everything looks tight and dry you can re-cowl the airplane (usually the hardest part of the entire job). You'll need your helper again to get the lower cowl in place. Remember to re-secure the two fasteners for the air-box duct, the two cowl flap clevises and the landing light connector - which will need a couple of new Ty-raps.
And that's it! All that's left is to make the appropriate entry in the engine's maintenance log, send off the oil sample to the lab, and cut open the filter to inspect the media for stray metal (which process will be the subject of a future post.)