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8-2
BATTERY
SERVICE PROCEDURES
BATTERY VISUAL INSPECTION
(1)
Protect the paint finish with fender covers.
(2) Disconnect the battery cables at the battery.
(3)
Remove the battery hold-down clamp and re-
move the battery from the vehicle.
(4)
Inspect the battery carrier and fender side panel
for damage caused by loss of acid from the battery.
(5) Clean the top of battery with a solution of clean
warm water and baking soda. Scrub areas with a stiff
bristle brush being careful not to scatter corrosion
residue. Finallly wipe off with a cloth moistened with
ammonia or baking soda in water.
CAUTION: Keep cleaning solution out
of battery
cells to eliminate weakening the electrolyte.
(6)
Inspect the cables. Replace damaged or frayed
cables.
(7) Clean the battery terminals and the inside sur-
faces of the clamp terminals with the Cleaning Tool
(8)
Examine the battery case and cover for cracks.
(9)
Install the battery.
(10) Tighten the battery hold-down screw nuts to
NOTE: Observe the polarity of the terminals of bat-
tery to be sure the battery is not reversed.
(11) Connect the cable clamps to the battery posts
and tighten securely. Coat all connections with light
mineral grease or petrolatum after tightening.
(12) If the electrolyte level is low,
fill
to recom-
mended level with mineral-free water.
MX-75.
3
foot-pounds.
SPECIFIC GRAVITY TEST
A hydrometer Tool 40-B is used to measure the
specific gravity of the electrolyte in the battery cells.
This gives an indication of how much unused sulphu-
ric acid remains in the solution.
A hydrometer should be graduated
to read from
1.160
to 1.320, in graduations of
.005
specify gravity.
The graduated markings should be not less than
'Ile
inch apart and accurate to within
.002
specific gravity.
The graduated portion of the stem should be about
two inches long. Clearance between the float and glass
barrel, at the smallest diameter, should be a minimum
of Ys" around all sides and the barrel must be clean.
NOTE: Hydrometer tloats are calibrated to indicate
correctly only at one fixed temperature.
The liquid level of the battery cell should be at
normal height and the electrolyte should be thorough-
ly mixed with any battery water which may have just
been added
by
charging the battery before taking any
hydrometer readings. See "Adjustment of Acid Grav-
ity."
In reading a hydrometer, the barrel must be held
vertically and just the right amount of fluid be drawn
up into the gauge barrel with the pressure bulb fully
expanded to lift the float freely so that it does not
touch the sides, top or bottom of the barrel. Take a
reading with eye on level with liquid in barrel.
DO
NOT TILT
hydrometer.
The specific gravity of the battery electrolyte
strength or density varies not only with the quantity
of the acid in solution but also with temperature.
As
temperature increases, the volume of the electrolyte
expands and the specific gravity is reduced. As tem-
perature drops, the electrolyte contracts and specific
gravity increases.
Specific gravity variations caused by temperatures
must be considered in the analysis of the battery,
otherwise specific gravity readings will not give a true
indication of the state of charge.
Use a battery immersion type thermometer of the
mercury-in-glass type, having a scale reading as high
as 125°F and designed for not over a 1-inch bulb im-
mersion. A suitable dairy type thermometer may
prove satisfactory for the purpose.
Draw electrolyte in and out of the hydrometer bar-
rel several times to bring the temperature of the hy-
drometer float to that of the acid in the cell and then
measure the electrolyte temperature in the cell.
Tompordun
F.
onnlty
?. I *
to Add
u
Fig.
1
--Hydrometer Reading Correction Chart
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