This document provides step-by-step instructions for changing aviation engine oil, oil filters, and cleaning oil screens on Lycoming and Continental engines. It describes draining the old oil, identifying the type of filter or screen on the engine, removing and replacing it, adding new oil, inspecting for leaks, and making appropriate logbook entries.

1. HOW TO CHANGE AVIATION OIL, OIL FILTERS AND CLEAN OIL SCREENS STEP 1 When performing any inspection or maintenance on the powerplant, propeller or that requires turning on the master switch, or pulling the propeller through by hand; treat the propeller as if the ignition switch were on. DO NOT stand, nor allow anyone else to stand, within the arc of the propeller as a loose or broken wire or component malfunction could cause the propeller to rotate.

2. STEP 2 When you have finished viewing this presentation, use the “CAPS” program found on the home page of www.apex- inc .biz . Select the proper oil filter (under Oil Filters) or oil screen gasket (under Gaskets & Seal Kits) for your aircraft. Aviation oil is also available through CAPS. Tools needed to perform this task can be found under “ Aircraft Oil Change Tools & Supplies ” about half way down the page.

3. STEP 3 Perform ground run to warm up oil, in accordance with manufacturer’s flight manual. Remove cowlings as necessary to gain access to the oil filter and drain plug.

4. STEP 4 CAUTION : Oil is hot. Use a proper recycling container when draining oil. Cut the safety wire on the oil drain plug and remove the plug. Discard the crush washer. If a quick drain is installed, push up and twist to lock the drain open.

5. IF YOU HAVE: GO TO STEP # LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER 5 LYCOMING ENGINE WITH OIL SCREEN 6 CONTINENTAL ENGINE WITH OIL SCREEN 7

6. STEP 5 LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER Cut the safety wire on the oil filter and note the position on the accessory case where the filter was safety wired. You will need to know this when the filter is reinstalled and safety wired.

7. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER A small trough can be made to place under the oil filter to drain the oil away from the accessory case when the filter is removed. Using a 1” (one inch) box end wrench, loosen and remove the oil filter.

8. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER Lube the gasket on the new oil filter before it is installed. DC-4 (or equivalent) is the recommended lube.

9. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER Using a torque wrench, torque the oil filter to the value on the filter. Safety wire the filter to the previously noted correct location.

10. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER If a drain plug was removed, reinstall the plug with a new crush washer. Torque the plug as described in the following.

11. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER Place an index mark across the brass plug and the accessory case with a fine point permanent marker. This index mark is used to correctly torque the crush washer.

12. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER The torque value is determined by the number of degrees that the brass nut is turned when tightened. This correctly crushes the washer to achieve a seal.

13. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER For example, the brass nut uses a thread pitch of 16 threads per inch and the torque value is 135 degrees. While looking at the index mark you made, tighten the nut 135 degrees. The most common mistake is to overtorque the crush washer which damages the seal and it will leak oil. Safety wire the plug.

14. STEP 5 (continued) LYCOMING OR CONTINENTAL ENGINE WITH OIL FILTER If a quick drain valve is installed, twist the valve and close the drain. Skip to Step 8

15. STEP 6 LYCOMING ENGINE WITH OIL SCREEN Carefully remove temperature sensor wire or tube assembly, if installed into the screen housing. This temperature sensor may have a small copper tube or an electrical connection. In either case, be VERY CAREFUL not to twist the tube or the post on the electrical connection or damage could occur and either part is very expensive to replace.

16. Remove the four bolts or screws attaching the screen housing to the accessory case. Remove the screen from inside the housing and thoroughly clean housing and screen with solvent. Inspect for any metal particles when cleaning. If any metal is found, contact your maintenance shop for professional advice. Remove old gasket material from screen housing or accessory case. DO NOT use any tools that would scratch the metal surfaces. We suggest using a hard plastic scraper. When all old gasket material has been removed, install new gasket on housing using the screws to hold the gasket in place. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN

17. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN Install the housing in the correct position on the accessory case and finger tighten all four bolts or screws. Tighten bolts or screws to 50-70 in lbs of torque. DO NOT over torque or damage could occur to the accessory case. Reinstall temperature sensor if removed.

18. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN If a drain plug was removed, reinstall the plug with a new crush washer. Torque the plug as described in the following.

19. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN Place an index mark across the brass screen assembly and the accessory case with a fine point permanent marker. This index mark is used to correctly torque the crush washer.

20. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN The torque value is determined by the number of degrees that the brass nut is turned when tightened. This correctly crushes the washer to achieve a seal between the oil screen and the accessory case.

21. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN For example, the brass nut uses a thread pitch of 16 threads per inch and the torque value is 135 degrees. While looking at the index mark you made, tighten the nut 135 degrees. The most common mistake is to overtorque the crush washer which damages the seal and it will leak oil. Safety wire the plug. Reinstall the temperature sensor (if it was removed) and safety wire the screen.

22. STEP 6 (continued) LYCOMING ENGINE WITH OIL SCREEN If a quick drain valve is installed, twist the valve and close the drain. Skip to Step 8

23. STEP 7 CONTINENTAL ENGINE WITH OIL SCREEN The oil screen is located in the rear accessory case and looks like a one inch brass hex nut.

24. STEP 7 CONTINENTAL ENGINE WITH OIL SCREEN Some screens will have a oil temperature sensor threaded into this one inch brass hex nut. If so, the temperature sensor must be removed VERY CAREFULLY. DO NOT twist the small copper tube connected to the temperature sensor or the temperature sensor will have to be replaced and this can be very expensive. When the temperature sensor is removed (if installed), cut the safety wire on the oil screen assembly.

25. STEP 7 (continued) CONTINENTAL ENGINE WITH OIL SCREEN Using a one inch socket, unscrew the oil screen assembly, remove and discard the crush washer. Clean the screen in solvent and inspect for any metal particles. If any metal is found, contact your maintenance shop for professional advice. Install the new crush washer on the screen assembly and reinstall screen in accessory case. Thread screen into accessory case by finger pressure until crush washer has contacted accessory case housing.

26. STEP 7 (continued) CONTINENTAL ENGINE WITH OIL SCREEN If a drain plug was removed, reinstall the plug with a new crush washer. Torque the plug as described in the following.

27. STEP 7 (continued) CONTINENTAL ENGINE WITH OIL SCREEN Place an index mark across the brass screen assembly and the accessory case with a fine point permanent marker. This index mark is used to correctly torque the crush washer.

28. STEP 7 (continued) CONTINENTAL ENGINE WITH OIL SCREEN The torque value is determined by the number of degrees that the brass nut is turned when tightened. This correctly crushes the washer to achieve a seal between the oil screen and the accessory case.

29. STEP 7 (continued) CONTINENTAL ENGINE WITH OIL SCREEN For example, the brass nut uses a thread pitch of 16 threads per inch and the torque value is 135 degrees. While looking at the index mark you made, tighten the nut 135 degrees. The most common mistake is to overtorque the crush washer which damages the seal and it will leak oil. Safety wire the plug. Reinstall the temperature sensor (if it was removed) and safety wire the screen.

30. STEP 7 (continued) CONTINENTAL ENGINE WITH OIL SCREEN If a quick drain valve is installed, twist the valve and close the drain.

31. STEP 8 Service the engine with oil to the correct level and type of oil.

32. STEP 9 Remove any tools or supplies from the engine compartment. Perform a ground run per manufacturer’s flight manual and inspect the oil filter for leaks. Reinstall any cowlings.

33. HOW TO CHANGE AVIATION OIL, OIL FILTERS AND CLEAN OIL SCREENS INSTALLATION COMPLETE Make appropriate logbook entry of the work performed. The FAA has a sample logbook entry shown in the free video on our home page at www.apex- inc .biz . This presentation contains information that is consistent with FAR 65.83 “Recent Experience Requirements.” Please visit www.apex- inc .biz to view a free video that reviews Basic Maintenance for Pilots and Technicians as part of FAR 43 and 91. Click on “Watch the video” located about half way down on the left side of the page.