Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 662 / 881

4 . Remove the back of the air box and flapper valve assembly. Lubricate the shaft with lubriplate as
n e cessary.
5. Check the condition and operation of the flapper. Make sure the shaft moves freely in the bearings and
the rivets retaining the bearings are in proper condition. Replace the rivets if the bearings exhibit any
looseness, and make sure the bearings retain their proper alignment.
6. Remove the safety wire and follow with the four bolts securing the assembly to the carburetor.
7. With the assembly removed inspect the box for cracks and proper sealing.
8. Reinstallation should be accomplished in the reverse order of removal. Once the assembly is installed
make sure the flapper valve moves freely before installing control cable.
REMOVAL AND INSTALLATION OF PA-44-180 CARBURETOR HEAT SHROUD.
1. Remove the bottom cowl.
2. Carburetor heat is supplied by a duct interconnected with a shroud mounted to the cylinder No. 4
exhaust manifold. The duct can be removed by first removing the clamps retaining it to the air box
and shroud fixtures.
3. Remove the screws securing the outboard shell of the shroud and slide it forward out of the main
shroud support.
4. Remove the bolts securing the shroud to the exhaust stack.
PA-44-180T SNIFFLE VALVE MAINTENANCE.
The sniffle valve, located on the inboard side of each bottom cowl, functions to permit any liquid in the
intake manifold to drain when the engine is shut down. If the valve mechanism fouls and engine operation is
erratic, the valve should be replaced or cleaned as follows:
1. Remove the back/up retaining nut and washer, which will release the valve from the bottom cowl.
2. Remove the bottom cowling and inspect the hose, tubing, and fittings interconnected with the valve for
excessive wear, corrosion, or other defects.
— NOTE —
If the engine is running lean at low power settings, and rich at
high power setting, with the sniffle valve in working condition,
the lines interconnecting the sniffle valve and intake manifold
may be allowing air to enter or escape the manifold.
3. Make sure the hose is not touching the engine and that it is installed without dips.
4. Disconnect the valve from the hose.
5. The valve can be checked for proper operation by trying to inhale or exhale through the valve outlet.
The valve should prevent either. If a leak exists soak the valve in an ultrasonic cleaner, or lacquer thinner.
The valve should operate properly or be replaced.
6. Connect the valve to the hose.
7. Position the valve in the cowling and secure with nut and washer.
8. Run the engine to insure proper installation.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
71-62-00
Page 71-18
Revised: May 15, 1989
3E16