Lycoming TEO-540-C1A Maintenance Manual page 128

Problem
Critical altitude is
lower than specified
High deck pressure
(Compressor
discharge pressure)
12-30
Page 98
Table 1 (Cont.)
Fault Isolation Guide
Cause
Exhaust bypass control
valve is not getting
enough oil pressure to
close the exhaust bypass
valve actuator
Exhaust bypass control
valve is not correctly
operating
Metering jet in actuator is
blocked
Exhaust bypass valve
actuator piston seal is
leaking and cannot be
serviced
Leak in exhaust system
Damaged compressor
impeller blades
Exhaust bypass valve is
not opening correctly
Oil pressure is too high
Exhaust bypass valve is
not operating correctly
TEO-540-C1A Engine Maintenance Manual
TEO-540-C1A Engine Maintenance Manual
Corrective Action
Examine these components for
leaks or obstructions:
• Pump outlet pressure
• Oil filters
• External lines
Replace the exhaust bypass
valve.
Remove the actuator and the
clean the jet.
1. Examine the actuator drain
for leaks.
2. Clean the cylinder and
replace the piston seal.
Identify and correct the cause
of the leak.
Replace the turbocharger.
Examine the exhaust bypass
valve to make sure that the shut
off valve in the return line is
operating correctly.
Examine the butterfly shaft for
binding.
Replace the exhaust bypass
valve or correct linkage
binding.
1. Make sure that the pressure
is correct at the exhaust
bypass actuator inlet.
2. If the pressure on the outlet
side of the actuator is too
high, make sure that the
turbocharger control valve
is operating correctly.
Replace the exhaust bypass
valve.
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Ref.
72-40
72-40
78-00
72-40
November 2018