CHEVROLET CAMARO 1967 1.G Chassis Workshop Manual

SECTION 6T

AIR INJECTION REACTOR SYSTEM

INDEX

Page

General Description 6T-1

Maintenance Procedures 6T>1

Drive Belt. ...-..' 6T-1

Inspection 6T-1

, Adjustment . . 6T-1

Replacement 6T-1

Drive Pulley . . . . 6T-1

Replacement 6T-1

Pump Pulley ....................... 6T-1

Replacement. 6T-1

Air Manifold, Hose and Tube
...........>*.
6T-2

Inspection . . 6T-2

Replacement 6T-2

Check Valve (s) 6T-3
Page

Inspection 6T-3

Replacement . . 6T-3

Mixture Control Valve 6T-3

Inspection 6T-3

Replacement 6T-3

Air Injection Tube 6T-4

Inspection . . . ... . . . .... 6T-4

Replacement 6T-4

Air Injection Pump 6T-4

Inspection 6T-4

Replacement . 6T-4

Pressure Relief Valve Replacement 6T-4

Special Tools 6T-5

GENERAL

The Air Injection Reactor (A.I.R.) System (fig. 1) con-

sists of: the air injection pump (with necessary brackets

and drive attachments), air injection tubes (one for each

cylinder), a mixture control valve, check valves (one for

In Line engines, two for V8 engines) and air manifold as-

semblies, tubes and hoses necessary to connect the

various components.

Carburetors and distributors for engines with the

A.I.R. System are designed, particularly, for these en-

gines;
therefore, they should not be interchanged with or

replaced by a carburetor or distributor designed for an

engine without the A.I.R. System.

The air injection pump (fig. 2) picks up fresh filtered

air from the air cleaner, compresses the air and injects

it through the air manifolds, hoses and injection tubes

into the exhaust system in the area of the exhaust valves.

The fresh air ignites and burns the unburned portion of

the exhaust gases in the exhaust system, thus minimizing

exhaust contamination.

The mixture control valve (fig. 3) when triggered by a

sharp increase in manifold vacuum, supplies the intake

manifold with fresh filtered air to lean out the fuel-air
DESCRIPTION

mixture and prevent exhaust system backfire.

The check valve(s) prevent exhaust gases from entering

and damaging the air injection pump, as back flow can

occur even under normal operating conditions.

When properly installed and maintained, the A.I.R.

System will keep exhaust emissions well below require-

ments. However, if any A.I.R. component or any engine

component that operates in conjunction with the A.I.R.

system should malfunction, the exhaust emissions might

be increased.

Because of the relationship between "Engine Tune

Up"
and "Unburned Exhaust Gases", the condition of

Engine Tune Up should be checked whenever the A.I.R.

System seems to be malfunctioning. Particular care

should be taken in checking items that affect fuel - air

ratio such as the crankcase ventilation system, the

carburetor and the carburetor air cleaner.

Because of the similarity of many parts, typical illus-

trations and procedures are used except where specific

illustrations or procedures are necessary to clarify the

operation. For Repair Procedures on the Air Injection

Pump,
refer to the Passenger Chassis Overhaul Manual.

MAINTENANCE PROCEDURES

Drive Belt

Inspection

• Inspect drive belt for wear, cracks or deterioration

and replace if required.

• Inspect belt tension and adjust if below 50 lb. using a

strand tension gauge.

Adjustment

• Loosen pump mounting bolt and pump adjustment

bracket bolt.

• Move pump until belt is tight (55±5 lb. used belt or

75±5 lb. new belt using a strand tension gauge) then

tighten adjustment bracket bolt and mounting bolt.

CAUTION: Do not pry on the pump housing.

Distortion of the housing will result in extensive

damage to the Air Injection Pump.

Replacement

• Loosen pump mounting bolt and pump adjustment
bracket bolt then swing pump until drive belt may be

removed.

• Install a new drive belt and adjust as outlined above.

Drive Pulley .

Replacement

• Remove drive belt as outlined above then replace

drive pulley.

• Install and adjust drive belt as outlined above.

Pump Pulley

Replacement

• Hold pump pulley from turning by compressing drive

belt then loosen pump pulley bolts.

• Remove drive belt as outlined above then remove

pump pulley.

• Install pump pulley with retaining bolts hand tight.

CHEVROLET CHASSIS SERVICE MANUAL

AIR INJECTOR REACTOR SYSTEM
6T-2

AIR

MANIFOLD
MIXTURE

CONTROL

VALVE

AIR

INJECTION

PUMP

IN LINE
MIXTURE

CONTROL

VALVE

AIR INJECTION

PUMP

CHECK

VALVE

V8

Fig.
I—Air
Injection Reactor System (Typical)

• Install
and
adjust drive belt
as
outlined above.

• Hold pump pulley from turning
by
compressing drive

belt then torque pump pulley bolts
to 25 ft. lbs.

• Recheck drive belt tension
and
adjust
if
required.

Air Manifold, Hose and Tube

Inspection (Fig. 4)

• Inspect
all
hoses
for
deterioration
or
holes.

• Inspect
all
tubes
for
cracks
or
holes.

PUMP

HOUSING

91

DRIVE V

HUB

PRESSURE

RELIEF VALVE
•H
PUMP
'

Mm ^
COVER

A.

J^HTEXHAUST

wBBE
TUBES

SB

^1 INTAKE

JH TUBE
• Check
all
hose and tube connections.

• Check
all
tube
and
hose routing. Interference
may

cause wear.

•
If a
leak
is
suspected
on the
pressure side
of the

system
or any
tubes and/or hoses have been discon-

nected
on the
pressure side,
the
connections should

be checked
for
leaks with
a
soapy water solution.

With
the
pump running, bubbles will form
if
aleak

exists.

Replacement

•
To
replace
any
hose and/or tube, note routing then

remove hose(s) and/or tube(s)
as
required.

CAUTION:
The 1/4"
pipe threads
at the
cylin-

der head
(In
Line)
or
exhaust manifold
(V8) are

VALVE
IN

OPEN

POSITION
INLET

VALVE
IN

CLOSED

POSITION

DIAPHRAGM

POSITIONS
SIGNAL
LINE

CONNECTION

ALVE

Fig.
2—Air Injection Pump
Fig.
3—Mixture Control Valve

CHEVROLET CHASSIS SERVICE MANUAL

AIR INJECTOR REACTOR SYSTEM
6T-3

MIXTURE

CONTROL

VALVE

SIGNAL

PUMP PRESSURE

(MIXTURE VALVE INLET)

PUMP PRESSURE

(AIR MANIFOLD INLET)

IN LINE
AIR INJECTION

PUMP INLET

MIXTURE

CONTROL

VALVE

SIGNAL

MIXTURE

CONTROL

VALVE

OUTLET

MIXTURE

CONTROL

VALVE

INLET
AIR INJECTION

PUMP INLET

V8 (TYPICAL)
PUMP PRESSURE

(AIR MANIFOLD INLET)

MIXTURE CONTROL

VALVE INLET

MIXTURE CONTROL

VALVE SIGNAL

AIR INJECTION

PUMP INLET

PUMP PRESSURE^

(AIR MANIFOLD

J

MIXTURE CONTROL

VALVE OUTLET
V8 (396-427)

Fig.
4—Air Manifold Hose and Tube Routing (Typical)
a straight pipe thread.
Do
not use
a 1/4"
tapered

pipe
tap. The
hoses
of
the
Air
Injection Reactor

System
are a
special material
to
withstand high

temperature.
No
other type hose should
be

substituted.

• Install
new
hose(s) and/or tube(s), routing them
as

when removed.

• Tighten
all
connections.

NOTE:
Use
anti seize compound
on
threads
of

the
air
manifold
to
exhaust manifold
or
cylinder

head connections.

NOTE:
On
Chevy
n
vehicles equipped with
a

V8 engine,
the air
injection tubes
are
part
of the

air manifold
and
care must
be
used
in
removing

them from
the
exhaust manifold.
It may be

necessary
to
remove
the
exhaust manifold
and

use penetrating
oil on the
injection tubes before

the
air
manifold can
be
removed.

Check Valve

Inspection

•
The
check valve should
be
inspected whenever
the

hose
is
disconnected from
the
check valve
or
when-

ever check valve failure
is
suspected. (A pump that

,
had
become inoperative and had shown indications
of

having exhaust gases
in the
pump would indicate

check valve failure)..

• Orally blow through
the
check valve (toward
air

manifold) then attempt
to
suck back through check

valve. Flow should only
be in one
direction (toward

the
air
manifold).

Replacement

• Disconnect pump outlet hose
at
check valve. Remove

check valve from
air
manifold, being careful not
to

bend
or
twist
air
manifold.

Mixture Control Valve

Inspection

• Check condition
and
routing
of all
lines especially

the signal line.
A
defective signal
or
outlet line will

cause malfunctioning
of the
mixture control valve.

• Disconnect pump
to
valve inlet hose
at
pump.

• Leaking valve will
be
indicated
by an air
gushing

noise coming from
the
hose. Place palm
of
hand over

hose; little
or no
pull with
a
gradual increase
is

normal.
If
immediate strong pull
is
felt
or air
noise

is heard, valve
is
defective
and
should
be
replaced.

• Open
and
close throttle rapidly.
Air
noise should
be

evident
and
then gradually decrease. Check
for

proper valve usage.
If
strong pull
is not
felt
im-.

mediately
or air
noise
is not
present, valve
is not

functioning properly and should be replaced.

•
A
noisy valve should be replaced.

Replacement

• Disconnect
the
signal line,
air
inlet
and air
outlet

hoses then remove
the
valve.

• Install
new
valve
and
connect
air
outlet,
air
inlet

and signal line hoses.

CAUTION: Mixture control valves, though

similar
in
appearance
are
designed
to
meet

particular requirements
of
various engines,

therefore,
be
sure
to
install
the
correct valve.

CHEVROLET CHASSIS SERVICE MANUAL

AIR INJECTOR REACTOR SYSTEM 6T-4

Air injection Tube

Inspection (Fig. 5)

• There is no periodic service or inspection for the

air injection tubes, yet on In Line engines whenever

the cylinder head is removed or on V8 engines when-

ever the exhaust manifolds are removed, inspect the

air injection tubes for carbon build up and warped or

burnt tubes.

• Remove any carbon build up with a wire brush.

• Warped or burnt tubes must be replaced.

Replacement

• On In Line engines remove carbon from tubes and

using penetrating oil, work tubes out of cylinder

head.

• On V8 engines clamp exhaust manifold in a vise,

remove carbon from tubes and using penetrating oil,

work tubes out of manifold.

• Install new tubes in cylinder head or manifold.

Air Injection Pump

Inspection

Accelerate engine to approximately 1500 KPM and

observe air flow from hose.Osf). If air flow increases as

engine is accelerated, pump is operating satisfactorily.

If air flow does not increase or is not present, proceed

as follows:

• Check for proper drive belt tension.

• Check for a leaky pressure relief valve. Air maybe

heard leaking with the pump running.

NOTE:
The Air Injection Reactor System is

not completely noiseless. Under normal condi-

tions noise rises in pitch as engine speed in-

creases. To determine if excessive noise is the

fault of the Air Injection Reactor System, oper-

ate the engine with the pump drive belt removed.

IN LINE

INJECTION

si

AIR AAANIFOLD^

ASSEMBLY
AIR MANIFOLD

ASSEMBLY ^S

~jk
VALVE

V-8

ff

>yi
INJECTION

» TUBE
' ,•

Fig.
5—Air Injection Tube (Typical)
Fig.
6-HRemoving Pressure Relief Valve

If excessive noise does not exist with the belt

removed proceed as follows:

Check for proper installation of relief valve silencer

on L-6 and 283, 327, 350 cu. in. V-8 engines.

Check for a seized Air Injection Pump.

Check hoses, tubes, air manifolds and all connec-

tions for leaks and proper routing.

Cheqk carburetor air cleaner for proper installation.

Check air injection pump for proper mounting.

If none of the above conditions exist and the air in-

jection pump has excessive noise remove then repair

as outlined in the Overhaul Manual.

Replacement

Disconnect,
t&e
hoses at the pump.

Remove pump pulley as outlined.

Remove pump mounting bolts and remove pump.

Install pump with mounting bolts loose.

Install pump pulley as outlined.

Install and adjust belt as outlined.

Connect the hoses at the pump.

Pressure Relief Valve Replacement

1.
Using J-7055-5 and J-6585 pull relief valve from

housing (fig. 6).

2.
Using a 15/16" socket tap the relief valve into hous-

ing until the valve shoulders on the housing (fig. 7).

CAUTION: Use extreme care to avoid distort-

ing housing.

NOTE:
Various length pressure setting plugs

(fig. 8) designed for the particular requirements

of vehicle - engine combinations, determine the

CHEVROLET CHASSIS SERVICE MANUAL

AIR INJECTOR REACTOR SYSTEM 6T-5

LEGS LOCK
ON

INSIDE SURFACE
/

BLUE-194,
230

SILVER-250

GREEN-283

BLACK-327,
350, 396 & 427
PRESSURE

RELIEF VALVE

Fig.
7—Installing Pressure Relief Valve
Fig.
8—Pressure Setting Plug

pressure required to open the relief valve. For

identification, the pressure setting plugs are

color coded. To remove the pressure setting

plug, carefully unlock legs from inside surface

of relief valve with a small screw, driver. To

install the pressure setting plug, carefully push

into relief valve until legs lock. If a pressure

setting plug is to be reused be sure leg angles

are sufficient for the pressure setting plug to

lock in place.

SPECIAL TOOLS

J-7055-5

J-6585

J-21844

J-21058

Fig.
9-Special Tools

CHEVROLET CHASSIS SERVICE MANUAL

SECTION 6Y

ENGINE ELECTRICAL

CONTENTS
OF
THIS SECTION

Page

System

6Y-19
6Y-32

6Y-34

BATTERY

INDEX

Page

General Description 6Y_i

Types of Batteries 6Y-1

Dry Charged Batteries 6Y-2

Activating Dry Charged Batteries 6Y-2

Wet Charged Batteries 6Y 2

Periodic Service 6Y-3

Common Causes of Failure 6Y-3

Delco Eye 6Y_3

Electrolyte Level
AY
3

Water Usage ] \ 6Y_3

Cleaning 6Y_4

Cables 6Y_4

Carrier and Holddown 6Y-4
Page

Safety Precautions 6Y-4

Charging Procedures . . gY_4

Slow Charging gY-4

Fast Charging . * 6Y-4

Emergency Boost Charging 6Y-4

Test Procedures QY-S

Visual Inspection 6Y-5

Instrument 6Y-5

Full Charge Hydrometer Test. 6Y-5

Specific Gravity Readings 6Y-5

Cell Comparison Test . 6Y-5

Installing Battery 6Y-5

GENERAL DESCRIPTION

The battery (fig. lb) is made up of a number of separ-

ate elements, each located in an individual cell in a hard

rubber case. Each element consists of an assembly of

positive plates and negative plates containing dissimilar

active materials and kept apart by separators. Hie ele-

ments are immersed in an electrolyte composed of dilute

sulfuric acid. Plate straps located on the top of each ele-

ment connect all the positive plates and all the negative

plates into groups. The elements are connected in series

electrically by connectors that pass directly through the

case partitions between cells. The battery top is a one-

piece cover of hard rubber construction. Tfte cell con-

nectors, by-passing through the cell partitions, connect

the elements along the shortest practical path (fig. 2b).

With the length of the electrical circuit inside the

Battery reduced to a minimum, the internal voltage drop

is decreased resulting in improved performance, par-

ticularly during engine cranking at low temperatures.

The hard, smooth one-piece cover greatly reduces the

tendency for corrosion to form on the top of the Battery.

The cover is bonded to the case with sealing compound

that forms an air tight seal between the cover and case.

Protection for the Battery charging circuit (10 gage

wire) is provided by a pigtail lead which is a fusible Hnk

off the battery positive cable (14 gage wire). This lead is

an integral part of the Battery cable assembly and serv-

icing requires replacing the complete cable assembly.

TYPES
OF
BATTERIES

There are two types of Batteries—the "dry charge"

type and the "wet charge" type. The difference in types

depends on the method of manufacture.
ONE PIECE

CELL COVER

VENT PLUG
ELECTROLYTE LEVEL

INDICATOR

HOLD-DOWN SLOT

Fig.
lb—Battery

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-2

PARTITION

PLATE

STRAP

CONNECTOR

Fig.
2b—Internal View of Two Cells Showing Connector

through Partition

DRY CHARGED BATTERIES

A "dry charge" Battery contains fully charged ele-

ments which have been thoroughly washed and dried. Hiis

type of Battery contains no electrolyte until it is activated

for service in the field and, therefore, leaves the factory

in a dry state. Consequently, it is called a "dry-charge"

Battery.

Each vent well in a "dry charge" Battery has an inte-

gral hard rubber seal to prevent the entrance of air and

moisture which would oxidize the negative active mate-

rials and reduce the freshness of the Battery (fig. 3b).

The integral hard rubber seals and the sealing compound

between the case and one-piece cell cover make possible

a. vacuum sealed assembly which can be stored for very

long periods of time without detrimental effects.

Before activating the "dry charge" Battery, the inte-

gral hard rubber seals may be broken simply by pushing

the Delco Eye down into each vent well. The seals drop

into the cells, and can remain there since they are not

chemically active and will cause no harm. (The Delco

Eye is a special type of vent plug that is described in the

section entitled "Periodic Servicing".)

ACTIVATING DRY CHARGED BATTERIES

A "dry charge" Battery is activated by filling each

cell with electrolyte, which is a dilute solution of sulfuric
VENT WELL

SEAL

SPLIT VENT

Fig. 3b—Vent Well Construction Showing Seal

acid having a specific gravity of 1.265 at 80°F. The cells

are properly filled when the electrolyte level reaches

the bottom of the "split vent" at the bottom of the vent

well. The split vent is a visual level fill feature designed

into the cell cover of Delco Batteries (fig. 4b). The elec-

trolyte surface will appear distorted when it contacts the

split vent.

The electrolyte level of each cell should be checked

after filling the Battery initially. If the level has fallen

below the split vent, additional electrolyte should be

added. NEVER APD WATER TO THE ELECTROLYTE

WHEN ACTIVATING BATTERY.

Ir?ong and trouble-free service can be anticipated only

if the Battery is properly activated. Improper activation

results in poor performance and short Battery life.

After electrolyte has been added to a "dry charge"

Battery, it then becomes a wet charged Battery and

should be maintained in the same manner as any other

"wet" Battery.

WET CHARGED BATTERIES

Wet charged Batteries contain fully charged elements

and are filled with electrolyte before being shipped from

the factory.

ELECTROLYTE

LEVEL TOO

LOW
ELECTROLYTE

AT CORRECT

LEVEL

Fig. 4b-View Inside Vent Well Showing Electrolyte

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-EIECTRICAI 6Y-3

PERIODIC SERVICING

Since the Battery is a perishable item which requires

periodic servicing, a good maintenance program will

insure the longest possible Battery life.

COMMON CAUSES OF FAILURE

If the Battery tests good but fails to perform satis-

factorily in service for no apparent reason, the following

are some of the more important factors that may point to

the cause of the trouble.

1.
Vehicle accessories inadvertently left on overnight to

cause a discharged condition.

2.
Slow speed driving of short duration, to cause an

3.
undercharged condition.

A vehicle

capacity.
electrical load exceeding the generator

4.
Defect in the charging system such as high resist-

ance, slipping fan belt, faulty generator or voltage

regulator.

5. Battery abuse, including failure to keep the Battery

top clean, cable clamps and posts clean and tight,

and improper addition of water to the cells.

LEVEL INDICATOR

The Battery features an electrolyte level indicator,

which is a specially designed vent plug with a transparent

rod extending through the center (fig. 5b). When the elec-

trolyte is at the proper level, the lower tip of the rod is

immersed, and the exposed top of the rod will appear

very dark; when the level falls below the tip of the rod,

the top will glow. ,

The Indicator reveals at a glance if water is needed,

without the necessity of removing the vent plugs (fig. 6b).

The Level Indicator is used in only one cell (second

cell cap from positive Battery post) because when the

electrolyte level is low in one cell, it is normally low in

all cells. Thus when the Indicator shows water is needed,

check the level in all six cells.

An alternate method of checking the electrolyte level is

to remove the vent plug and visually observe the electro-

lyte level in the vent well. The bottom of the vent well

features a split vent which will cause the surface of the

electrolyte to appear distorted when it makes contact.

The electrolyte level is. correct when the distortion first

appears at the bottom of the split vent (fig. 4b).

ELECTROLYTE LEVEL

The electrolyte level in the Battery should be checked

regularly. In hot weather, particularly during trip driv-

ing, checking should be more frequent because of more

rapid loss of water. If the electrolyte level is found to be

low, then colorless, odorless, drinking water should be

added to each cell until the liquid level rises to the split

vent located in the bottom of the vent well. DO NOT

OVERFILL because this will cause loss of electrolyte

resulting in poor performance, short life, and excessive

corrosion.

CAUTION: During service only water should be

added to the Battery, not electrolyte.

The liquid level in the cells should never be allowed to

drop below the top of the plates, as the portion of the
INDICATOR

ELECTROLYTE LEVEL

CORRECT

Fig.
5b—Cut-Away View Showing Electrolyte at Proper Level

with Indicator Having Dark Appearance

plates exposed to air may be permanently damaged with a

resulting loss in performance.

WATER USAGE

Excessive usage of water indicates the Battery is being

overcharged. The most common causes of overcharge

are high Battery operating temperatures, too high a volt-

age regulator setting, poor regulator ground wire con-

nection. Normal Battery water usage is approximately

one to two ounces per month per battery.

INDICATOR

Fig.
6b—Cut-Away View Showing Electrolyte at Low Level

with Indicator Having Light Appearance

CHASSIS SBtVKZ MANUAL

ENGINE-ELECTRICAL
6Y-4

CLEANING

The external condition of the Battery should be checked

periodically for damage or for the presence of dirt and

corrosion. The top of the Battery should be kept clean.

An accumulation of acid film and dirt may permit current

to flow between the terminals, which will slowly dis-

charge the Battery. For best results when cleaning the

top of Batteries, wash first with a diluted ammonia or a

soda solution to neutralize any acid present; then flush

with clean water. Care must be taken to keep vent plugs

tight, so that the neutralizing solution does not enter the

cells.

CABLES

To insure good electrical contact, the cables should be

clean and tight on the Energizer posts. If the posts or

cable terminals are corroded, the cables should be dis-

connected and the terminals and clamps cleaned sepa-

rately with a soda solution and a wire brush. After

cleaning and installing clamps, apply a thin coating of

petroleum jelly on the cable clamps to retard corrosion.

CARRIER
AND
HOLD-DOWN

The Battery carrier and hold-down should be clean and

free from corrosion before installing the Battery. The

carrier should be in a sound mechanical condition so that

it will support the Battery securely and keep it level.

To prevent the Battery from shaking in its carrier,

the hold-down bolts should be tight (60-80 in. lbs.). How-

ever, the bolts should not be tightened to the point where

the Battery case or cover will be placed under a severe

strain.

BATTERY SAFETY PRECAUTIONS

When Batteries are being charged, an explosive gas

mixture forms in each cell. Part of this gas escapes

through the holes in the vent plugs and may form an

explosive atmosphere around the Battery itself if ventila-

tion is poor. This explosive gas may remain in or around

the Battery for several hours after it has been charged.

Sparks or flames can ignite this gas causing an internal

explosion which may shatter the Battery.

The following precautions should be observed to pre-

vent an explosion:

1.
Do not smoke near Batteries being charged or which

have been very recently charged.

2.
Do not break live circuits at the terminals- of Batr

teries because a spark usually occurs at the point

where a live circuit is broken. Care must always be

taken when connecting or disconnecting booster leads

or cable clamps on fast chargers. Poor connections

are a common cause of electrical arcs which cause

BATTERY CHARGING PROCEDURES

There are three methods of recharging Batteries.

They differ basically in the length of time the Battery is

charged and the rate at which charging current is sup-

plied. One is the Slow Charge method, the second is the

Fast Charge method, and the third is the Emergency

Boost Charge method.

Before recharging a Battery by any method, the elec-

trolyte level must be checked and adjusted if necessary.
SLOW CHARGING

The Slow Charge method supplies the Battery with a

relatively low current flow for a relatively long period of

time. This is the only method that will bring the Battery

to a full state of charge.

The Slow Charge method consists of charging at

approximately a 4 ampere rate for 24 hours or more if

necessary to bring the Battery to full charge. A fully

charged condition is reached when the cells are gassing

freely and three corrected specific gravity readings

taken at hourly intervals show no increase.

FAST CHARGING

The Fast Charge method supplies current to the Bat-

tery at a 40 to 50 ampere rate for a 1 1/2 hour period of

time. If the electrolyte temperature reaches 125°F before

the 1 1/2 hour period is completed, the Battery must be

taken off charge temporarily, or the charging rate

reduced to avoid damage to the Battery.

Although a Battery cannot be brought to a fully charged

condition during Fast Charge, it can be substantially

recharged or "boosted". In order to bring the Battery to

a fully charged condition, the charging cycle must be

finished by the Slow Charge method.

EMERGENCY BOOST CHARGING

In cases where the Battery is not sufficiently charged

to crank the engine, an emergency boost charge may be

applied as a temporary expedient in order to crank the

engine. The Emergency Boost Charge method consists of

charging at a 40 to 50 ampere rate for a period of one-

half hour.

It should be particularly noted that the Emergency

Boost Charge will not necessarily restore the Battery to

a useful state of. charge for continued service. After an

emergency boost charge, failure to charge the Battery

further, either by a long uninterrupted driving period or

by the Fast Charge or Slow Charge method, may result

in failure to crank the engine the next time cranking is

attempted. A Battery should never be condemned on the

basis of failure to crank the engine after an emergency

boost charge. Although an emergency boost charge may

put enough energy into the Battery to crank the engine

once, further charging usually is necessary in order to

create a sufficient reserve to crank a second and third

time.

12
VOLT BATTERY SUGGESTED

CHARGING RATES

(100 Amp/hr or Less Capacity)

TYPE OF

CHARGE

Boost Charge for

Light Load Test

Slow Charge

Fast Charge

Quick Boost .

Dry Charge

Warm-up Boost
LENGTH

OF TIME

20 Minutes

24 Hours

1-1/2 Hours

30 Minutes

10 Minutes
CHARGING

RATE

50 Amps

4 Amps

40-50 Amps

40-50 Amps

15 Amps

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE—ELECTRICAL 6Y-5

BATTERY TESTING PROCEDURES

Testing procedures are used to determine whether the

Battery is (1) good and usable, (2) requires recharging or

(3) should be replaced. Analysis of Battery conditions can

be accomplished, by performing a visual inspection,

Instrument Test, and the full charge hydrometer test.

1.
VISUAL INSPECTION

The first step in testing the Battery should be a visual

inspection, which very often will save time and expense

in determining Battery condition.

• Check the outside of the Battery for a broken or

cracked case or a broken or cracked cover. If any

damage is evident, the Battery should be replaced.

« Note the electrolyte level. Levels that are too low or

too high may cause poor performance, as covered in

the section entitled "Periodic Servicing".

o Check for loose cable connections, and for evidence

of corrosion as covered in section entitled ' 'Periodic

Servicing". Correct as required before proceeding

with tests.

2.
INSTRUMENT TEST

A number of suppliers have approved testing equipment

available. These testers have a programmed test proce-

dure consisting of a series of timed discharge and

charge events, requiring approximately 2 to 3 minutes,

that will determine the condition of the Battery with a

high degree of accuracy. When using these testers, the

procedure recommended by the tester manufacturer

should be followed. Batteries should not be charged prior

to testing as doing so may alter the test results. If a

tester is not available for testing, the "Specific Gravity

Cell Comparison Test" may be used or an alternate

method, but with a sacrifice in testing accuracy.

3. FULL CHARGE HYDROMETER TEST

This test should be used only on Batteries which test

good with testing equipment or "Specific Gravity Cell

Comparison Test" but which subsequently fail in service.

• Remove the Battery from the vehicle, and adjust the

electrolyte level as necessary, by adding colorless,

odorless, drinking water.

• Fully charge the Battery at the Slow Charging rate

as covered in the section entitled "Battery Charg-

ing".

• Measure the specific gravity of the electrolyte in

each cell and interpret as follows:

Hydrometer Reading Less Than
1.230—Full
charge

hydrometer readings less than 1.230 corrected for

temperature indicate the Battery is defective and

should be replaced.

Hydrometer Readings Above
1.310—Full
charge hy-

drometer readings above 1.310 corrected for tem-

perature indicate that the cells have been improperly

filled (activation) or improperly serviced. Poor

service and short Battery life will result.

SPECIFIC GRAVITY READINGS

A hydrometer can be used to measure the specific

gravity of the electrolyte in each cell.

The hydrometer measures the percentage of sulphuric
acid in the battery electrolyte in terms of specific

gravity. As a battery drops from a charged to a dis-

charged condition, the acid leaves the solution and enters

the plates, causing a decrease in specific gravity of

electrolyte. An indication of the concentration of the

electrolyte is obtained with a hydrometer.

When using a hydrometer, observe the following points:

1.
Hydrometer must be clean, inside and out, to insure

an accurate reading.

2.
Hydrometer readings must never be taken immedi-

ately after water has been added. The water must be

thoroughly mixed with the electrolyte by charging for

at least 15 minutes at a rate high enough to cause

vigorous gassing.

3.
If hydrometer has built-in thermometer, draw liquid

into it several times to insure correct temperature

before taking reading.

4.
Hold hydrometer vertically and draw in just enough

liquid from battery cell so that float is free floating.

Hold hydrometer at eye level so that float is vertical

and free of outer tube, then take reading at surface of

liquid. Disregard the curvature where the liquid

rises against float stem due to surface tension.

5.
Avoid dropping battery fluid on car or clothing as it

is extremely corrosive. Any fluid that drops should

be washed off immediately with baking soda solution.

The specific gravity of the electrolyte varies not only

with the percentage of acid in the liquid but also with

temperature. As temperature increases, the electrolyte

expands so that the specific gravity is reduced. As

temperature drops, the electrolyte contracts so that the

specific gravity increases. Unless these variations in

specific gravity are taken into account, the specific

gravity obtained by the hydrometer may not give a true

indication of the concentration of acid in the electrolyte.

A fully charged Battery will have a specific gravity

reading of approximately 1.270 at an electrolyte temper-

ature of 80°F. If the electrolyte temperature is above or

below 80°F, additions or subtractions must be made in

order to obtain a hydrometer reading corrected to the

80°F standard. For every 10° above 80°F, add four

specific gravity points (.004) to the hydrometer reading.

Example: A hydrometer reading of 1.260 at 110°F would

be 1.272 corrected to 80°F, indicating a fully charged

Battery. For every 10° below 80°F, subtract four points

(.004) from the reading. Example: A hydrometer reading

of 1.272 at 0°F would be 1.240 corrected to 80°F, indi-

cating a partially charged Battery.

Specific Gravity Cell Comparison Test—This test may

be used when a instrument tester is not available. To

perform this test measure the specific gravity of each

cell, regardless of state of charge, and interpret the

results as follows:

• If specific gravity readings show a difference be-

tween the highest and lowest cell of .050 (50 points)

or more, the Battery is defective and should be

replaced.

INSTALLING BATTERIES

To install a Battery properly, it is important to ob-

serve the following precautions:

• Connect grounded terminal of Battery last to avoid

short circuits which may damage the electrical

system.

CHEVROLET CHASSIS SERVICE MANUAL