Mooney M20TN, Service And Maintenance Manual

Page: 266 / 1169

MOONEY AVIATION COMPANY, INC.
M20TN SERVICE & MAINTENANCE MANUAL
Page
Date
12
2006
Rev Date
areas constitute a flight hazard. Fastener leaks of this
category may be temporarily repaired by applying a
sealant fillet over fastener head on fuel tank exterior.
For a temporary repair to be satisfactory, structural in-
tegrity must be retained in leak area. To make a tempo-
rary fastener--leak repair:
(1) Remove enough fuel from tank to drop fuel
level below leaking fasteners.
(2) Clean fastener head and adjacent surface
with Turco 657 Wipe Solvent or Methyl Ethyl Keytone
(MEK) and dry thoroughly. Fastener head and adjacent
metal must be entirely free from paint, dirt, and oil.
(3) Apply a 1/8 inch thick coat of PR 1422 (or
CS3204) B--1/2 or B--2 over head and around fastener.
(4) Allow sealant to cure until firm and rubbery.
(5) Refill tank and examine repair periodically. If
leak reoccurs, sealant must be removed and area re-
cleaned prior to making another temporary repair.
B. Permanent Leak repair. If leak source is found to
be around a rivet or threaded fastener, the repair proce-
dure shall be to restrike rivet or retorque fastener to
maximum permitted torque value. Any one rivet may be
restruck only one time. If leak continues, replace the
rivet.
(1) Repair any sealant damage due to restriking
or retorqueing a fastener.
(2) Remove sealant in immediate area of leak
source using a sharp non--metallic tool. A chisel--
shaped Formica tool is recommended. Scarf or taper
ends of existing sealant so that new sealant can form a
continuous and smooth overlap.
(3) Thoroughly clean repair area using Turco
657 Wipe Solvent or Methyl Ethyl Keytone (MEK).
Wash one small area at a time. To prevent redeposit of
oil and dirt on surface, dry with a clean cloth before sol-
vent evaporates. Always pour solvent onto wash cloth
to prevent contamination of solvent supply; do not dip
cloth into solvent.
(4) Thoroughly dry cleaned area by blowing fil-
tered air over immediate area until there is no possibility
of solvent or fuel entrapment under adjacent sealant.
(5) Apply sealant as required for repair (See Fig-
ure 28--4). Repaired fillets must be blended into exist-
ing fillets with a spatula or an appropriate tool.
(6) Allow all repaired sealant to cure tack--free
and apply two brush coats of PR 1005--L to repair area
(Refer to paragraph 28--11--00, 4, D).
28--13--00 -- SOAPLESS BUBBLE FLUID FORMU-
LA PREPARATION FOR LEAK CHECK
-- CAUTION --
Soapless bubble fluid is slightly corrosive and
must be completely removed by washing freely
with water followed by scrubbing.
NOTE:
Amount of each ingredient may be reduced for a
smaller quantity of solution. Solution life is about
one week.
1. Materials.
A. Three ounces of either sodium bichromate, po-
tassium chromate or potassium dichromate.
B. Three and one--quarter ounces Thickening Wax
(Carbo Wax 1500).
C. Thirteen ounces Alkaryl Sulfonate wetting
agent.
D. Distilled water.
2. Solution Preparation.
A. Mix one of the compounds listed in item (A)
above with one cup distilled water.
B. Mix item (B) above with one cup distilled water.
C. Mix item (C) above with four to four and one half
gallons distilled water until wetting agent dissolves
completely.
D. Mix the three ingredients (A), (B) and (C) togeth-
er and add enough distilled water to make five gallons
of solution.
28--14--00 -- FUEL ADDITIVES
-- CAUTION --
Ethylene glycol monomethyl ether (EGME) or
other additives are not recommended due to po-
tential deteriorating effects within the fuel sys-
tem.
Under certain conditions of temperature and humidity,
water can be present in fuel in sufficient quantities to
create ice formations within the fuel system. To prevent
this, add Anhydrous ISOPROPYL Alcohol to the fuel
supply in quantities not to exceed 3% of total fuel vol-
ume per tank.
28--20--00 -- DISTRIBUTION
The fuel system is comprised of two fuel pumps, an en-
gine driven, gear type pump and an electrically driven,
auxiliary, boost pump. The electrically driven boost
pump is connected to switches (Low Boost & High
Boost) on the instrument panel. The boost pump is
used to provide fuel pressure for starting and to assist in
hot, ground operations to prevent vapor lock.
28--21--00 -- FUEL BOOST PUMP REMOVAL AND
INSTALLATION
1. Auxiliary, Electric, Boost Pump Removal.
A. Remove electrical leads.
B. Turn fuel selector valve -- OFF.
C. Disconnect inlet and outlet fuel lines.
D. Remove fuel pump.
2. Reverse the removal procedure for reinstallation.
Refer to SECTION 71--00--51, 4 for Electric Boost
Pump Set--Up.
28--13--00