Piper CHEROKEE WARRIOR PA-28-151 1995 Maintenance Manual page 333

PIPER CHEROKEE WARRIOR SERVICE MANUAL
c. With the engine running at medium rpm, the suction gauge should indicate 4.8 to 5.2 inches of
m e r c u r y. If reading is not within this range, shut down engine, and adjust regulator valve by moving the valve
adjustment screw clockwise to increase the pressure and counterclockwise to decrease the pressure. Start
engine and repeat check. With engine running at medium rpm the suction gauge should indicate 4.8 to 5.2
inches of mercury. lf the airplane is not equipped with a suction gauge, it will be necessary to connect a tempo-
rary gauge by:
1 . Removing the plug from the back of the attitude deviation indicator.
2 . Install a temporary gauge into the back of the attitude deviation indicator.
d. Restart engine and repeat check.
e. After system pressure has been adjusted to the recommended settings, replace the protective cap or
retighten the lock nut per type of valve installed.
f . If a temporary gauge was used, remove the gauge and install plug into the back of the attitude
d e v iation indicator.
10-13. REMOVAL AND INSTALLATION OF VACUUM REGULATOR VALVE
a. Disconnect the three vacuum lines. Mark to facilitate installation.
b. Disconnect and mark electrical wires.
c. Remove mounting nut. Remove regulator valve.
d. Install regulator valve in reverse order of removal.
10-14. ENGINE DRIVEN VACUUM PUMP.
10-15. GENERAL.
The engine driven vacuum pump is a rotary vane, positive displacement type. This unit consists of an
aluminum housing containing a tempered sleeve in which an offset rotor is incorporated. This assembly is
d r iven by a coupling mated to the engine driven gear assembly. The pump is mounted on the accessory section
of the engine.
10-16. TROUBLESHOOTING.
Refer to Table X-l for troubleshooting of the vacuum pump.
10-17. REMOVAL AND INSTALLATION OF ENGINE DRIVEN VACUUM PUMP. (Refer to Figures
10-1 and 10-2)
a. To remove engine driven vacuum pump. (Refer to Figures 10-1 and 10-2.):
1. Remove engine cowling.
2. Loosen hose clamp. Remove and mark hose to facilitate installation.
3 . Remove the four retaining nuts, lock washers and plain washers that secure pump to engine.
4. Remove pump.
b. Installation of engine driven vacuum pump. (Refer to Figures 10-1 and 10-2.):
The only pump mounting gasket authorized and approved for
use on Airborne vacuum pumps is Piper p/n 751 859 (Warrior
II), or 461 907 (Warrior III). Any other gaskets can result in
oil seepage or leakage at the mounting surface.
Revised: February 28, 1995
CAUTION
Never install a pump that has been damaged or dropped.
CAUTION
2B21
Island Enterprises
INSTRUMENTS