Service Instruction No. 1553 DATE: March 26, 2013
SUBJECT: Additional Cylinder Fin Stabilizer
MODELS AFFECTED: IO540 E1B5 TIO540A2B,A2C,J2B,J2BD,F2BD,S1ADL
As a precaution to prevent cracks from forming in the intake wall between the cylinder fins No. 1 thru 15 Lycoming Engines recommends that an additional fin stabilizer P/N 75164 be installed on cylinder P/N LW12966 on the affected Lycoming engine models identified in SI.
To install the new stabilizer P/N 75164 on the cylinder fins:
1. If the engine is installed, remove the exhaust system and intercylinder baffles (in accordance with the applicable instructions in the applicable overhaul manual).
2. Examine each cylinder in the fin area (where shown in Figure 1) for cracks.
3. If a crack is found, replace the engine cylinder (in accordance with the applicable instructions in the applicable overhaul manual).
4. If no cracks are found, thoroughly clean the fin stabilizer and cylinder fin areas 1 thru 15 on the engine cylinder with mineral spirits or equivalent solvent to remove all traces of grease, dirt, or other foreign matter; air dry with compressed air.
5. Apply Dow Corning DC3145 RTV silicone adhesive (or equivalent adhesive compliant with MILA46146) to the mating side the fin stabilizer.
6. Install the new additional fin stabilizer (adhesive side flat against the cylinder fins) on each engine cylinder between cylinder fins No. 1 thru 15 as shown in Figure 2. One end of the fin stabilizer is toinstall securely between cylinder fin Nos. 1 and 2; the other end of the fin stabilizer is to install securely between cylinder fin Nos. 14 and 15.
7. Press the fin stabilizer evenly against the cylinder fin surface for adhesive sealing.
8. After 15 minutes, make sure the fin stabilizer is attached firmly to the cylinder fins.
9. Reinstall the intercylinder baffles and exhaust system (in accordance with the applicable instructions in the applicable overhaul manual).
10. Record the installation of this additional fin stabilizer on all the engine cylinders as per this Service Instruction in the engine logbook.