Piper Comanche PA-24 Service Manual page 800

B. Removal
1. Remove engine cowling.
2. Loosen hose clamp and remove hose from pump fittings.
3. Remove four retaining nuts, lock washers and plain washers used to secure pump to engine;
then remove pump.
C. Installation
CAUTION: A PUMP THAT HAS BEEN DAMAGED OR DROPPED SHOULD NOT BE
INSTALLED.
NOTE: Change the vacuum system filter when installing a new pump.
1. If required, install fittings on pump per Replacing Pump Fittings, below.
CAUTION: ONLY PUMP MOUNTING GASKET AUTHORIZED AND APPROVED FOR
2. Place pump gasket in its proper place and align spline on pump drive with spline on engine
drive assembly.
3. Secure pump to engine with four plain washers, lock washers and retaining nuts. Torque nuts
50 to 70 inch-pounds.
4. Connect hoses to pump and secure with hose clamps.
5. Reinstall engine cowling.
D. Replacing Pump Fittings
CAUTION: WHEN REPLACING ANY OF THE THREADED FITTINGS, DO NOT USE PIPE
DOPE, THREADLUBE, OR TAPE. PIPE DOPE / TAPE PARTICLES INGESTED
BY THE VACUUM PUMP COULD CAUSE THE PUMP TO FAIL. USE ONLY
SILICONE SPRAY, LETTING IT DRY BEFORE ASSEMBLY.
CAUTION: A PUMP THAT HAS BEEN DAMAGED OR DROPPED SHOULD NOT BE
INSTALLED.
1. Before installing any fittings on pump, check for any external damage.
CAUTION: DO NOT APPLY VISE PRESSURE TO OUTSIDE DIAMETER OR OVERALL
2. When a vise is used to hold pump while installing fittings, suitable caution must be exercised
to avoid pump damage. Square mounting flange must be held between soft wood blocks and
only at right angles to vise jaws. Use only enough vise pressure to hold pump firmly.
3. The ports of AIRBORNE pumps have been treated with a dry film lubricant and AIRBORNE
fittings are cadmium plated thus eliminating any need for thread lubricants. If thread
lubricant is required, use only a silicone spray. Apply sparingly to external threads of
fittings only and let dry before assembly.
4. Firmly hand tighten fittings into pump ports. Then, using a wrench, tighten each fitting 1/2 to 2
turns only. Do not over tighten.
04/01/09
PIPER COMANCHE SERVICE MANUAL
USE ON AIRBORNE VACUUM PUMP IS AIRBORNE GASKET B3-1-2,
PIPER PART NUMBER 751-859. USE OF ANY OTHER GASKET MAY
RESULT IN OIL SEEPAGE OR LEAKAGE AT MOUNTING SURFACE.
LENGTH OF PUMP.
3F23
XI - INSTRUMENTS