Cleaning Plug Electrode; Gapping Spark Plug - Ford 1961 TRUCK 100 SERIES Shop Manual

Bl006-A
FIG_
l-Cleaning Plug Eledrode
If a minor tune-up is being per-
formed, install the spark plugs and
torque them to 15-20 ft-Ibs.
2. Take A Compression Reading
Of Each Cylinder. Remove the coil
high tension lead at the distributor
cap. Set the throttle plates (primary
throttle plates on ly on the 4-barrel
carburetor) and choke plate in the
wide open position.
Install a compression gauge in No.
1 cylinder.
Using a remote starter switch,
crank the engine several times and
record the highest reading recorded.
Note the number of compression
strokes required to obtain the highest
reading.
Repeat the test on each cy linder,
cra nking the engine the sa me num-
ber of tVncs for each cylinder as was
requir ed to obtain the highest read-
ing on the No. 1 cylinder.
A variation of
±
20 pounds from
specified pressure (150 psi at crank-
ing speed) is satisfactory. However,
the compression of all cylinders
should be uniform wi thin 10 pounds.
A reading of more than the allow-
FIG.
2-Gapping Spark Plug
PART 1-1- GENERAL ENGINE SERVICE
able tolerance above norm al indi-
cates excessive deposits in the cyl-
inder.
A reading of more than the allow-
able tolerance below normal indi-
cates leakage at the cylinder head
gask.et, piston rings, or valves.
A low even compression in two
adjacent cylinders indicates a cylin-
der head gasket leak. This shou ld be
checked before condem ning the rings
or valves.
To determine whether the rings or
the valves are at fa ult , squir t the
equivalent of a tablespoon of heavy
oil into the combustion chamber.
Crank the engine to distribute the oil
and repeat the compression test.
The
o il wi ll temporarily seal leak age past
the rings. If approximately the
sa me
reading is obtai ned, the rings are
satisfactory, but the va lves are leak-
ing. If the compress ion has in creased
'10 pounds or more over the origi nal
re adi ng, there is leakage past the
rin gs.
During a compression test, if the
pressure fails to climb stead ily and
remains the same during the first two
successive strokes, but climbs higher
on the sllcceed ing strokes, or fails to
climb during the entire test, it indi-
cates a sticking valve.
A fter the compression test, install
the spark plugs. Torque them to
15-20 ft-Ibs. Do not install the coil
hi gh tensio n lead at this time.
3. Check And Tighten Inlake
Manifold Bolts. Check all intake
manifold bolts for the recommended
torque (23-28 ft-Ibs). Torque the
bolts as necessary starting at the cen-
ter bolts and working outwards.
4. Free the Exhaust Gas Control
Valve. Refer to Fig. 3 or 4. Check
the thermostatic spring of the valve
to make sure it is hook ed on the
stop pin. The sp ring stop is at the top
of th e valve housing when the va lve
is proper ly installed.
Make sure the spring hold s the
valve closed. Actuate the cou nter-
weight by hand to make sure it
moves freely through approximately
90 ° of rotation without binding.
Free a stuck va lve with FoMoCo
Exhaust Gas Control Valve Solvent
(CO AA-19A501-A) or a penetrating
oil and graphite mixture.
5. Check And Adjusl The De-
H,clion Of The Drive Belts. Check
the deflection of the drive belts using
tool 33-73F. Follow the instructions
of the tool manufacturer. Adju st the
tension as fo ll ows:
FIG.
3-223 Six Exhaust Gas
(ontrol Valve
1-9
SINGLE OR DOUBLE FAN
BELTS AND ALL GENERATOR
AND WATER PUMP BELTS.
Loosen the generator mounting bolts
and the adjusting bracket bolt. Move
the ge nerator toward or away from
the engine until the proper deflection
is obta ined between the water pump
pulley and the generator pulley.
Tighten the generator adjusting
bracket bolt and the mounting bolts.
SEPARATE FAN BELT. Loosen
the fan bracket mounting bolt. Slide
the bracket up or down to obtain the
recommended deflection between the
fan pu lley and the crankshaft pulley.
Tighten the fan bracket mounting
bolts.
On trucks equipped with an air
compressor, it may be necessary to
loosen the air compressor belt ad -
justment in order to obtain proper fan
belt adjustm ent. When the fan belt
adjustment is complete, always ad-
just the air compressor belt.
AIR COMPRESSOR BELT .
Loosen the air compressor mounting
bolts. Slide the compressor on its
mounting bracket to obtain the rec-
ommended deflection between the
compressor pulley and the fan pul-
ley (crankshaft damper on a C-Series
FIG.
4-292 MD
v-a
Exhaust
Gas (onlrol Valve