SECTION X
INSTRUMENTS
WARNING
When servicing or inspecting vendor equipment installed in Piper aircraft, it is the user’s responsibility to
refer to the applicable vendor publications.
10-1. GENERAL. The instrumentation is designed to give a quick and actual indication of the attitude,
performance and condition of the airplane. Maintenance, other than described in these sections, shall be done
by the instrument manufacturer or an authorized repair station.
The two types of instruments have been classified in this section as non-electrical and electrical. The first
part of this section will pertain to maintenance and troubleshooting of all the instruments and their systems
which depend on non-electrical sources for their operation.
10-2. NON-ELECTRICAL INSTRUMENTS.
10-3. VACUUM SYSTEM DESCRIPTION AND OPERATION. The following information is provided to
familiarize field service personnel with a means to diagnose vacuum systems malfunctions on those
components which are serviced by removal or replacement, along with recommended service practices. This
system operates the gyro instruments and consists of an engine driven dry vacuum pump, a vacuum regulator
and filter, and necessary hoses and lines that connect these components. Serial numbers 2837001 and up of the
PA-28R-201 and serial numbers 2803001 and up of the PA-28R-201T have auxiliary electrically operated dry
vacuum pumps incorporated in the system that provides a back-up source to operate the gyro flight instruments
if the engine driven pump fails. A vacuum gauge is used to constantly monitor the system.
CAUTION
DO NOT USE PIPE DOPE or any anti-seize tape or compound. The
AIRBORNE fittings are cadmium plated and need no other anti-seize
materials. Any ingested anti-seize materials may cause premature system
service. If a thread lubricant is required, use a powdered moly sulfide or
graphite in dry form or in an evaporating vehicle; or employ a silicone
spray. Apply sparingly to external threads of fittings only.
10-4. VACUUM SYSTEM SERVICE TIPS. (Refer to Table 10-1 for Troubleshooting Tips.)
CAUTION
Failure to inspect vacuum system hoses, clamps, and other components
periodically for leaks and security, will result in unreliable gyro instrument
indications.
10-5. HOSES AND CLAMPS. (Refer to Table 10-1 for Troubleshooting Instructions.)
a. Hoses and clamps should be examined periodically and inspected carefully when engine maintenance
activities cause hose disconnections to be made at the pump(s), regulating valve, gyro instruments, or
vacuum gauge.
Revised: 2/13/89
2F8
CHEROKEE ARROW III SERVICE MANUAL
INSTRUMENTS
To Next Page
Loading...
Need help?
General
