An incomplete review of all the information in this document can cause errors. Read the entire Service Bulletin to make sure you have a complete understanding of the requirements. Figures in this Service Bulletin are for illustration purposes only; your engine can appear differently.
This Service Bulletin is in response to field reports of exhaust leaks due to cracked welds and exhaust studs pulling from a cylinder on some Lycoming TIO-540-AJ1A engine models.
This revision of this Service Bulletin includes a new option: replacement of the complete exhaust system on affected engines per instructions in Part 1 of this Service Bulletin with a new stainless steel design. Replacement of the complete system eliminates the need to continue required exhaust system inspections per the schedule in Table 2 in Part 2 of this Service Bulletin.
If the exhaust system is not replaced with the new design, continue to complete the exhaust system inspections per Table 2 in Part 2 in this Service Bulletin.
THE FAA HAS APPROVED PART 1 OF THIS SERVICE BULLETIN AS TERMINATING ACTION TO AD 2017-11-10, AND PART 2 OF THIS SERVICE BULLETIN AS AN ALTERNATIVE METHOD OF COMPLIANCE TO AD 2017-11-10.
The following TIO-540-AJ1A engines shipped from Lycoming included the new design exhaust system at the time of overhaul, rebuild, or manufacture, and are in compliance with Part 1 of this Service Bulletin.
- Factory REBUILT and OVERHAUL engines with the supplied logbook entry dated on or after August 22, 2017
- Factory NEW engines beginning with serial number L-14337-61E
Prior to exhaust system removal, be sure to have one of two exhaust system replacement kits available:
- Part Number P/N 05J28882 for an exhaust system without holes for the Exhaust Gas Temperature (EGT) Probes.
- P/N 05J28883 for an exhaust system with holes for the EGT Probes.
Lycoming Engines is providing options for factory participation on engines that are within Lycoming’s factory warranty period and engines that are no longer within Lycoming’s factory warranty period. Refer to the most current revision of Lycoming Service Letter L275 for details.
Although this procedure identifies some airframe-installed exhaust components around the turbocharger as a point of reference, this procedure applies only to exhaust system components that are installed on the Lycoming TIO-540-AJ1A engine at the factory.
This procedure can be completed with the engine installed in the airframe.
1. Exhaust System Removal
PRIOR TO EXHAUST SYSTEM REMOVAL, LET THE ENGINE AND THE EXHAUST SYSTEM COOL FOR 1 HOUR OR LONGER AFTER ENGINE SHUTDOWN TO PREVENT BURNS. ENSURE THAT ALL POWER IS DISCONNECTED TO PREVENT ENGINE START.
ALL EXHAUST SYSTEM PARTS DESIGNATED TO BE DISCARDED IN THIS PROCEDURE MUST BE RENDERED UNAIRWORTHY. DO NOT RE-INSTALL THESE PARTS ON ANY ENGINE.
A. To access the exhaust system (Figures 1 and 2), remove any airframe components as necessary per the airframe manufacturer’s instructions.
B. Before removal of the exhaust system and for reference on reassembly:
(1) Take photos or draw a sketch of the exhaust system as installed and attached to the turbocharger.
(2) Identify the location of the No. 5 exhaust pipe V-band coupling, coupling gasket and flange to the exhaust transition assembly as the starting point for disassembly (Figure 4).
C. Remove and discard No. 5 exhaust pipe V band coupling and coupling gasket from the exhaust transition assembly flange (Figure 4).
D. Remove and discard the bolt and self-locking nut from the No. 2 exhaust pipe support clamp end of the cable assembly. Save the clamp for reassembly (Figure 4).
AS A SAFETY PRECAUTION, USE THREE PEOPLE TO COMPLETE THE NEXT STEPS TO PREVENT INJURY AND PARTS FROM FALLING.
E. While one person removes the self-locking nuts and washers from the vertical portion of the exhaust pipes on the engine (Figures 1 and 2), two people lower and remove the exhaust pipes as one piece and separate the pipes between No. 2 and No. 3 slip joint (Figure 4)
F. Remove the airframe exhaust shroud from No. 2 exhaust pipe taking note of the correct orientation of the exhaust shroud for reassembly on the new exhaust system. Discard all removed exhaust gaskets, washers and lock nuts.
G. Remove the flange from the exhaust transition assembly and discard.
For parts replacement using the item numbers shown in Figure 3, refer to the item numbers shown in parentheses in Figure 4 and Figure 5.
2. Exhaust System Installation
INCORRECT ASSEMBLY OF THE EXHAUST SYSTEM CAN ADVERSELY AFFECT ENGINE OPERATION OR RESULT IN THE RELEASE OF HOT TOXIC GASES.
A. Examine the kit components for damage. Replace any component that is damaged.
DO NOT USE ETCH TOOLS, GRAPHITE LEAD PENCIL, OR SCRIBE TO APPLY AN IDENTIFIER MARK ON EXHAUST PIPES. USE A NON-GRAPHITE MARKER SUCH AS COLORBRITE NO. 2127 OR 4127 OR A MARKS-A-LOT.
B. (Optional) Use a non-graphite marker such as Colorbrite No. 2127 or 4127 or a Marks-A-Lot marker to identify the exhaust system pipes on each side of the engine.
Clean the exhaust pipes, flanges, and slip joints as necessary, visually examine the exhaust pipes, flanges, and slip joints to ensure all connecting/mating surfaces are clean.
C. Apply a uniform coating of C5A Copper Based Anti-Seize or equivalent:
• Around the entire circumference of exhaust pipes at each slip joint
• Between the exhaust manifold connections, at all slip joints mating surfaces (to minimize binding)
• To the first three threads of each exhaust stud in all the cylinder heads.
D. Install the airframe exhaust shroud assembly over No. 2 exhaust pipe, and ensure the airframe exhaust shroud assembly installs at the correct angle to prevent binding and enable correct installation of the No.2 exhaust pipe. Reinstall the clamp for the cable support on No. 2 exhaust pipe.
E. Install the new flange into the exhaust transition assembly (Figure 4).
NOTICE: Do not force components into position, adjust as necessary for a loose fit. Assemble all the exhaust pipes as one unit before installing. Have two people lift the assembly into position while a third person installs all gaskets and hardware loosely to allow for adjustment.
F. Assemble each side of the exhaust system at the slip joints.
G. Slide the right and left sides of the exhaust system in place together slightly below the cylinders.
H. Install two new exhaust flange gaskets on each cylinder exhaust port (Figure 4). (Refer to the latest revision of Service Instruction SI-1204 for exhaust flange gasket information.)
I. Begin assembly of the exhaust system at the front of the engine and continue to the rear of the engine
J. Pull both sides up onto the studs all at the same time. Make sure there is no binding of the joined parts. If any binding or tightness is found adjust as necessary.
K. Install one new washer and one new self-locking nut loosely on each of the four cylinder exhaust port studs to allow for final adjustment in the next few steps. USE CARE TO SUPPORT THE ENTIRE EXHAUST SYSTEM DURING INSTALLATION. DO NOT FORCE, PRY, OR BEND COMPONENTS DURING FINAL ALIGNMENT TO PREVENT DAMAGE TO THE PARTS.
L. Align exhaust pipes in the correct configuration (per Figure 4 and your photo or sketch).
M. Make sure there are no gaps at pipe connections and all pipes are correctly aligned before beginning the torque sequence of the fasteners. ANY SELF-LOCKING NUTS, LOCK WASHERS, OR LOCK PLATE LOOSENED OR REMOVED TO GET CORRECT EXHAUST SYSTEM ALIGNMENT MUST BE DISCARDED AND REPLACED WITH NEW SELF-LOCKING NUTS, LOCK WASHERS, OR LOCK PLATE INCLUDED IN THE EXHAUST SYSTEM REPLACEMENT KIT.
Optional, the following steps, (1 thru 5 and i thru ix) outline the loosening and tightening of the turbocharger and associated mounting points to aid in new exhaust system alignment if required. All exhaust system components can be adjusted if needed to ensure proper alignment as the new exhaust system kit is installed, (Figure 5) Do not force or bend connecting parts, loosen in the order described following steps 1 thru 5.
(1) Remove the self-locking nut and washer from the stud that attaches the turbocharger mounting bracket to the exhaust transition assembly. Discard the self-locking nut, save the washer for reuse.
(2) Remove the three bolts and four self-locking nuts that attach the exhaust transition assembly to the turbocharger. Discard the bolts and self-locking nuts. Save the washers and exhaust transition assembly for reuse.
• If steps 1 and 2 achieve required exhaust system alignment, steps 3, 4 and 5 are not required. For reassembly, complete i and ii, as well as steps vi, vii, viii, and ix.
• If steps 1 and 2 do not achieve required alignment, continue to step 3.
(3) Remove and discard the horizontal bolt, lock washer and nut from the rear turbo bracket to the lug, keep the washers for reuse.
• If steps 1, 2, and 3 achieve required exhaust system alignment, steps 4 and 5 are not required. For reassembly, complete i, ii and iii as well as steps vi, vii, viii, and ix.
• If steps 1, 2, and 3 do not achieve required alignment, continue to step 4.
(4) Remove and discard the three self-locking nuts that attach the turbocharger brackets to the oil sump, keep the washers for reuse.
• If steps 1, 2, 3, and 4 achieve required exhaust system alignment, step 5 is not required.
For reassembly, complete i, ii, iii and iv as well as steps vi, vii, viii, and ix.
• If steps 1, 2, 3, and 4 do not achieve required alignment, continue to step 5.
(5) Remove the two attaching bolts and lock plate from the turbocharger mounting bracket and discard.
• For reassembly, complete steps i through ix.
• If steps 1 through 5 do not achieve required alignment, contact Lycoming Engines Product Support for assistance.
Use the following steps (i thru ix) as required for reassembly, if components are loosened, or removed (Figure 5).
i) Apply a uniform coating of C5A Copper Based Anti-Seize or equivalent to threads of bolts and studs prior to assembly.
ii) Complete the following:
(a) Loosely install the washers and new self-locking nuts on the studs on the exhaust transition assembly.
(b) Loosely install the lug (Figure 5) on the exhaust transition assembly with the new vertical bolt, washer, and new self-locking nut.
(c) Loosely attach the exhaust transition assembly to the turbocharger with two bolts, two washers, and two self-locking nuts.
iii) Loosely install the new horizontal bolt, washers, lock washer and nut through the rear turbocharger bracket into the lug.
iv) Loosely install the three washers and new self-locking nuts that attach the turbocharger brackets to the oil sump.
v) Loosely attach the two new bolts through a new lock plate, the turbocharger mounting bracket, and spacer into the turbocharger.
vi) Adjust brackets, exhaust transition assembly and turbocharger to gain proper exhaust system
alignment, and tighten bolts and nuts sufficiently to maintain alignment of the exhaust system. Do not over tighten. Torque hardware per the following steps.
vii) Torque the self-locking nuts on the 2 turbocharger to oil sump mounting brackets to 30 ft.-lbs.
viii) Torque the self-locking nuts that attach the exhaust transition assembly (Figure 5) to the turbocharger to 30 ft.-lbs. (40.7Nm)
ix) Torque the nut that attaches the exhaust transition assembly to the turbocharger mounting bracket (Figure 5) to 30 ft.-lbs. (40.7Nm)
THE V-BAND COUPLING AT THE EXHAUST TRANSITION ASSEMBLY MUST BE CORRECTLY ALIGNED. INCORRECT ALIGNMENT OF THE VBAND COUPLING AT THE EXHAUST TRANSITION ASSEMBLY IS AN INDICATION THAT THE EXHAUST SYSTEM IS NOT CORRECTLY INSTALLED. IF THE V-BAND COUPLING DOES NOT ALIGN, ADJUST THE EXHAUST SYSTEM COMPONENTS UNTIL THE V-BAND COUPLING IS IN CORRECT ALIGNMENT.
V-band couplings are used to seal joints in the exhaust system. The V-band coupling joint consists of the coupling, two flanges and a metal gasket. Correct installation of the V-band coupling is critical. Tubes and components to be joined must be aligned with each other before installation of the V-band coupling. Flanges must also be aligned correctly with zero gap between flange faces prior to V-band coupling installation to ensure good joint performance.
N. During installation of a new exhaust system, the new V-band coupling must be installed with a new gasket. Make sure that V-band coupling has a complete seal on an exhaust system component.
O. Install V-band couplings as follows:
(1) Slide the V-band coupling with a new gasket over the correct exhaust pipe.
(2) Adjust all the pipes to ensure the slip joints are not bound up at each joint.
DURING V-BAND COUPLING INSTALLATION, USE CARE NOT TO SPREAD OR FORCE THE COUPLING BEYOND ITS NORMAL OPEN POSITION TO PREVENT DISTORTION OF THE COUPLING. THIS DISTORTION CAN CAUSE AN INEFFECTIVE SEAL OR FRACTURE THE METAL WHICH CAN RESULT IN FAILURE OF THE COUPLING.
P. With the exhaust transition assembly attached, and flanges aligned, assemble the V-band coupling over the flanges of both pipes and new gasket.
Q. Engage the T-bolt.
R. Torque the V-band coupling to approximately 60 in.-lbs. (6 to 7 Nm)
S. If there is binding at a slip joint, loosen and re-adjust the components until they align correctly.
TORQUE HARDWARE FASTENERS EVENLY AND UNIFORMLY TO PREVENT LEAKS.
T. Complete final torques to ensure all fasteners are torqued.
U. Torque the 4 nuts that attach each pipe to the cylinders (Figure 4) to 96 in.-lb. (11 Nm) -on all cylinders.
V. Torque the V-band coupling at the inter-cylinder number 5 and exhaust transition assembly connection to 80-90 in.-lb. (10 Nm). Refer to the latest revision of Lycoming Service Instruction No. SI-1238 for Assembly and Torque Procedures for V-Band Couplings.
W. Install the exhaust system end of the cable assembly (Figure 4) with a new bolt and new self-locking nut. Torque the bolt and nut to 96 in.-lb. (10.9 Nm).
X. Torque any remaining loose hardware fasteners equally and uniformly per the standard Torque Tables in the latest revision of the Service Table of Limits – SSP-1776.
Y. Refer to the airframe manufacturer’s maintenance manual and reinstall all airframe components previously removed to gain access to the Lycoming exhaust system.
Z. Record replacement of the exhaust system (identify the kit part number) in the engine logbook.
Part 2 – Continued Exhaust System Inspections per Table 2 – Schedule for Exhaust System Inspections
If you do not replace the exhaust system with the specified kit per Part 1 of this Service Bulletin, you must continue to complete the exhaust system inspection per the schedule in Table 2 and instructions in Part 2 of this Service Bulletin.
TOXIC GASES, SUCH AS CARBON MONOXIDE, FROM LEAKS IN THE EXHAUST SYSTEM CAN POTENTIALLY ENTER THE COCKPIT.
The inspection in this Service Bulletin is in addition to the requirements of Service Bulletin No. SB-614A and AD 2015-10-06. Both are to be accomplished as specified in their respective compliance times.
Figures in this Service Bulletin are for illustration purposes only; your engine can appear differently.
1. Exhaust System Inspection
THE ENGINE AND EXHAUST SYSTEM CAN BE HOT AND COULD CAUSE BURNS. DO NOT CONDUCT THE EXHAUST SYSTEM INSPECTION WITHIN 1 HOUR OF OPERATING THE ENGINE AND UNTIL THE ENGINE AND EXHAUST ARE COOL.
This inspection can be done on an engine installed in an airframe. It is very important during this inspection to look for any stamped data on the Exhaust No. 2 and 3 pipes.
A. Examine Exhaust Pipe 2, identify any stamped markings.
The stamped markings for Exhaust Pipe 2 will have one of the following:
• Only the part number (P/N) (Figure 6). All pipes will be stamped with at least the P/N.
• The P/N and the Release ID# (Figure 7)
• The P/N, Release ID#, and a date code (Figure 8)
DO NOT OPERATE THE AIRCRAFT WITH A LEAKING ENGINE EXHAUST SYSTEM. OPERATION OF THE AIRCRAFT WITH AN EXHAUST SYSTEM LEAK CAN LEAD TO CARBON MONOXIDE POISONING, LOSS OF CONSCIOUSNESS, INJURY, OR DEATH.
E. Complete a visual inspection on the entire exhaust system (Figures 1 and 2). If any sign of leaks,
distortion, or damage is found, document the issue then replace with serviceable parts. 2. Flange Nut Torque Check
A. Since loose flange nuts can be an indication of a potential exhaust leak, complete a torque check on exhaust system flange nuts for all six cylinders.
B. If a flange, stud, flange nut, or pipe is distorted or visibly damaged, document the issue then replace with serviceable parts. If it is just a leaky gasket, determine root cause, and replace the gasket and hardware with new parts.
C. Check the fractional amount each flange nut turns to achieve the required 96 in.-lb (11 Nm) torque. If any flange nuts are loose enough to allow movement of the washer, contact Lycoming Engines’ Product Support.