Piper Navajo PA-31 Service Manual page 460

This relief regulates the engine oil pressure by allowing excessive oil to return to the sump. while the
balance of the pressure oil is fed to the main oil gallery in the right half of the crankcase. Residual oil is returned
by gravity to the sump. where after passing through a screen it is again circulated through the engine.
8-1a. STANDARD PRACTICES - ENGINE. The following suggestions should be applied wherever they
are needed when working on the power plant.
a. To insure proper reinstallation and or assembly, tag and mark all parts, clips, and brackets as to
their location prior to their removal and or disassembly.
b During removal of various tubes or engine parts, inspect them for indications of scoring, buring or
other undesirable conditions. To facilitate reinstallation, observe the location of each part during removal.
Tag any unserviceable part and/or units for investigation and possible repair.
c. Extreme care must be taken to prevent foreign matter from entering the engine, such as lockwire.
washers, nuts, dirt, dust, etc. This precaution applies whenever work is done on the engine, either on or off the
aircraft. Suitable protective caps. plugs. and covers must be used to protect all openings as they are exposed.
NOTE
Dust caps used to protect open lines must always be installed OVER
the tube ends and NOT IN the tube ends. Flow through the lines may
be blocked off if lines are inadventently installed with dust caps in
the tube ends.
d. Should any items be dropped into the engine, the assembly process must stop and the item removed.
even through this may require considerable time and labor. Insure that all parts are thoroughly clean before
assembling.
c. Never reuse any lockwire. lockwashers. tablocks. tabwashers or cotter pins. All lockwire and cotter
pins must fit snugly in holes drilled in studs and bolts for locking purposes. Cotter pins should be installed so
the head fits into the castellation of the nut, and unless otherwise specified, bend one end of the pin back over
the stud or bolt and the other end down flat against the nut. Use only corrosion resistant steel lockwire and /or
cotter pin. Bushing plugs shall be lockwired to the assembly base or case. Do not lockwire the plug to the
bushing.
f. All gaskets, packings and rubber parts must be replaced with new items of the same type at
reassembly Insure the new nonmetallic parts being installed show no sign of having deteriorated in storage.
g.
When installing engine parts which require the use of a hammer to facilitate assembly or
installation, use only a plastic or rawhide hammer.
h. Whenever, adhesive tape has been applied to any part, the tape and all residue must be removed and
thoroughly cleaned with petroleum solvents prior to being subjected to high temperature during engine run.
This would also apply to parts that have corrosion preventive compounds applied.
i.
Anti-seize lubrication should be applied to all loose-fit spline drives which are external to the engine
and have no other means of lubrication. For certain assembly procedures, molybdenum disulfide in either
paste or powdered form mixed with engine oil or grease may be used.
CAUTION
Ensure that Anti-seize compounds are applied in thin even coats,
and that excess compound
is completely removed to avoid
contamination of adjacent parts.
j. Temporary marking methods are those markings which will ensure identification during ordinary
handling, storage and final assembly of parts.
Revised: 9/23/80
POWER PLANT
2H10
PIPER NAVAJO SERVICE MANUAL