1967 CHEVROLET CAMARO service

ACCESSORIES 15-11

12 VOLTS D.C.
ELECTRIC BRAKE

RELEASE

IGNITION

SWITCH

ENGINE

VACUUM

TRANSDUCER

Fig.
11 - Vacuum and Electrical Diagram

AUTOMATIC LEVEL CONTROL

INDEX

Page

General Description . . 15-11

System Checks and Adjustments 15-13

Service Operation . 15-15

GENERAL DESCRIPTION

A pneumatic level control system that automatically

maintains correct rear trim height of a car under varying

load conditions, the optional automatic level control is

used only in conjunction with the Superlift Shock Absorber

option.

The Superlift Shock Absorber option alone, consists of

the two shock absorbers with pressure lines to a "Tee"

where a ill valve is located, the shocks are inflated

with (or deflated of) compressed air (at any gas station)

to obtain the vehicle level desired with any given load

change.

The automatic leveling system is added to the Superlift

Shock Absorbers and supplies its own compressed air.

The system (fig. 13) consists of a vacuum operated air

compressor with pressure regulator,
and
integral storage

tank, vacuum line to engine, air intake filter, air lines,

and a height control valve.

The COMPRESSOR is a two-stage, vacuum actuated

type, requiring no lubrication. Vacuum supply is taken

from engine carburetor base. High pressure air is
supplied to the reservoir tank by the second stage of

the two-stage compressor. The first stage intake stroke

draws air at atmospheric pressure through a oneway

check valve located in the end of the first stage housing

under the first ^tagei housing cover. On the first stage

compression stroke, the intake valve is closed and the

oneway check valve in the second stage end of the piston

is opened. This allows the air from the first stage

cylinder to flow through the hollow piston into the second

stage cylinder for jhigh pressure compression. The

second stage compression stroke closes the check valve

in the piston and opeijis the check valve in the end of the

second stage housing.

The intake and compression strokes are controlled by a

sliding distributor valive that is actuated through an arm

that is tripped by the piston as it nears the end of each

stroke. Each time the arm actuates the distributor

valve, a different set of holes are covered in the first

stage housing. The distributor valve controls the flow of

intake manifold vacuum and air under atmospheric pres-

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-12

VACUUM

(WIT

P

VACUUM Llh

, AIR SUPPt

LINES

t

SUPERLIFT F

SHOCK ABSO
OPERATED AIR COMPRESSOR

H STORAGE TANK AND

RESSURE REGULATORJV

\A

4E FROM ENG«NE^"^
/ \-HEIGHT CONTROL

•^-Z n VALVE (WITH TIME

^* DELAY MECHANISM)

EAR II

RBERS

Fig.
12 - Automatic Level Control Schematic

sure,
alternatley to opposite sides of the compressor

diaphragm.

As the compressor cycles, the reservoir air pressure

gradually increases causing a back pressure on the sec-

ond stage piston until it equals the push of pressure

against the diaphragm- At this point, a balanced condi-

tion is reached and the unit stops operating. After res-

ervoir pressure drops due to system air usage, the com-

pressor again begins to cycle and replenish the

reservoir.

Pressure balance will depend upon the prevailing mani-

fold vacuum and atmospheric pressure. Both are af-

fected by altitude above or below sea level. Balance

pressure will vary from approximately 150 to 275 psi.

NOTE: After completion of work on this sys-

tem or when servicing other parts of the car and

the system is deflated, inflate the reservoir to

140 psi or maximum pressure available through

the compressor service valve.

The PRESSURE REGULATOR VALVE is preset and

limits the reservoir outlet pressure to approximately 125

psi to avoid damage to the height control valve and Super-

lift shocks.

The HEIGHT CONTROL VALVE, which is mounted on

the frame, senses rear car height through a link attached

to the right rear upper control arm. When load is added

to the car, the overtravel lever is forced up causing an

internal lever to open the intake valve, when this valve

is open high pressure air is admitted to the Superlift

shocks. As the car raises to level, the intake valve shuts

off.

When load is removed from the car, the overtravel

lever is forced down causing the internal arm to open the

exhaust valve. As the car lowers to the level position,

the exhaust valve shuts off.

A four to eighteen second time delay mechanism, which

is built into the height control valve, prevents air trans-

fer due to normal ride movements. The overtravel

lever, which pivots around the control valve shaft, rides

off the flat side of the control valve shaft and does not

have time to. react to the rapid changes or normal ride

motions.
During changes due to loading, the time delay mecha-

nism will allow the overtravel shaft to open either the in-

take or exhaust' valve as required, since this is not a

rapid movement.

The SUPERLIFT shock absorber is essentially a con-

ventional hydraulic unit with a. pliable nylon reinforced

neoprene boot acting as an air chamber.

The unit will extend when inflated and retract when de-

flated by the control valve.

An eight to fifteen psi air pressure is maintained in the

Superlift at all times to minimize boot friction- This is

accomplished by a check valve in the exhaust fitting on

the control valve. Neither shock absorber function nor

conventional ride motions thru rear coil springs is im-

paired in the event of accidental air pressure loss. .

A combination of steel tubing and reinforced rubber

hose is used for air lines throughout the system.

-SUPERLIFT

PORT

STATION WAGON

& SEDAN

INTAKE

PORT
HAUST

PORT

Fig. 13 - Height Control Valve

AIR CHAMBER
BOOT

AIR DOME AIR PISTON

Fig. 14- Superlift Absorber

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-13

SYSTEM TEST
CHECKS AND ADJUSTMENTS

Automatic Level Control Test Gauge (Fig. 15)

A complete system test includes on and off-the-car

component tests.. '

On the car tests are:

Quick check of Automatic Level Control System

Compressor output test

Regulator test and adjustment

Control valve test

Time delay test

Line and fitting leak test

Trim adjustment

Off-the-car operations include:

Control valve replacement

Compressor repair

Component leak tests

a. Compressor, reservoir, and regulator

b.
Control valve

c. Superlifts

Quick Check-On Car (Reservoir Pressure at 150 PSI)

1.
Fill the fuel tank or simulate at the rate of 6 lbs./

gal.
- otherwise car should be empty.

2.
Turn engine off.

3.
Add a 2 passenger load to the rear bumper or tail-

gate.
Maintain the load until the -car lifts or AT

LEAST 20 SECONDS.

4.
After car lifts remove the load and observe until the

car lowers.

FILL VALVE

J-21999

CONNECTORS

Fig.
15 - Test Gauge Set J-22124
NOTE: To service the Automatic Level Con-

trol it will be necessary to secure Gauge Set

J-22124 or make up the following test gauge. If

the connectors indicated are not readily avail-

able others may be substituted.

1.
Collect the following parts:

a. Fill Valve, J-21999.

b.
A tee which has three 1/8M female taper pipe

threads.

c. An adapter which has a 1/4" female taper pipe

thread on one end and a 1/8" male taper pipe

thread on the other end.

d. Air Pressure Gauge, J-4872.

e. Two metal sleeves, rubber seals and tube nuts.

f. A length of 1/8" tubing. ~

g. Two male connectors which have a 1/8" male

taper pipe thread on one end and a 3/8-24 straight

thread male fitting on the other end.

2.
Assembly

a. Connect Fill Valve, J-21999, (female end) at male

connector 3/8-24 straight thread fitting.

b.
Connect other end of male connector to tee.

c. Connect adapter to tee.

d. Connect pressure regulator to adapter.

e. Connect second male connector to tee, (1/8 inch

male pipe thread fitting).

f. Install tubing to connector; other end of tubing

will go on unit to be checked.

NOTE:
Make certain all fittings are air tight.

Compressor Output Test—On Car

1.
With all accessories off, run the engine until fast idle

screw is off the fast idle cam. Turn off ignition.

2.
Deflate system through service valve, then remove

high pressure line at regulator adapter and connect

test gauge.

3.
Inflate reservoir to 70 psi through service valve.

4.
Observe test gauge for evidence of compressor air

leak.

5.
If leaking, proceed to leak test-compressor reser-

voir, and regulator. If not leaking, continue this

test.

6. With engine running at slow idle, observe reservoir

build-up for five minutes. Reservoir pressure should

build up to a minimum of 90 psi.

7.
If compressor fails to cycle, make sure the vacuum

and air intake lines are open and unobstructed before

removing compressor for repair.

8. If build-up is too slow, proceed to repair com-

pressor.

9. Satisfactory build-up indicates system problem to be

in the control section. However, again observe the

test gauge for evidence of an air leak and proceed

accordingly.

Regulator Test and Adjustment

Performance test the regulator with a known good com-

pressor on the car. *

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-14

Deflate system through service valve and disconnect

line at pressure regulator valve. Install test gauge on

regulator valve high pressure fitting.

Inflate system through service valve to maximum

available pressure.

NOTE: If available pressure is less than 140

psi,
start engine to build-up reservoir to this

pressure.

Regulated pressure should build-up to and hold

steady at 100-130 psi on test gauge.

Check regulated pressure by momentarily (not more

than one second) depressing valve core on test gauge

arid observe gauge reading.

If regulated pressure now reads less than 100 psi,

replace regulator assembly.

If regulated pressure exceeds 130 psi, replace regu-

lator assembly.

Control Valve Test

Exhaust (Superlifts Inflated)

1.
Disconnect control valve lever from link.

2.
Hold lever down in exhaust position until Superlifts

deflate or for a minimum of 18 seconds.

3.
If Superlifts deflate, perform Intake Check.

4.
If Superlifts do not deflate, remove exhaust adapter

from control valve and hold lever down as in Step 2.

Replace adapter, O-ring and filter if this deflates

Superlifts.

5.
Replace control valve if none of the above steps solve

problem.

Intake (Reservoir Pressure 125 psi Minimum)

1.
Disconnect overtravel lever from link.

2.
Hold lever up in intake position until Superlifts in-

Fig.
16 - Assembly Leak Test Preparation
flate or for a minimum of fifteen seconds.

3.
If Superlifts inflate and hold, proceed to Time Delay

Check. '•

4.
If Superlifts inflate and then leak down, perform leak

test on lines and fittings and then on Superlifts and

control valve. Repair or replace as indicated.

Time Delay Test (Reservoir Pressure 125 psi Minimum)

1.
Record rear trim height of empty car (rear bumper

to ground).

2.
Add weight equivalent to two passenger load to rear

of car. Car should begin to level in 4-18 seconds.

3.
Remove weight. After 4-18 seconds car should begin

to settle.

4.
Replace valve if time delay is not within the 4-18

seconds.

Trim Adjustment—On Car

Trim adjustment should be performed with a full fuel

tank (or the equivalent in load at the rate of 6 lbs
./gal-

lon)
,
but no other load.

Abbreviated Adjustment

1.
Fill the compressor at the service valve with the

available air line pressure.

2.
Disconnect link from height control valve lever.

Move the height control valve lever upward until air

fills the Superlifts.

3.
Move lever downward and hold until air stops escap-

ing from the exhaust port of the height control valve.

The Superlifts will now automatically hold 8 to 15

PSI.
;

4.
Let lever go to its neutral position> and loosen the

lever adjustment nut.

5.
Assemble the link to the height control valve lever

and tighten the lever adjustment nut.

NOTE: Do not move control valve lever and

overtravel body while tightening nut.

Leak Tests

Compressor, Reservoir and Regulator

1.
Remove assembly intact.

2.
Connect test gauge to regulator. Inflate reservoir

through service valve to 80-110 psi.

3.
Route an 8" rubber hose between vacuum and vent

ports,
(fig. 16).

4.
Submerge in water and observe for air leaks at:

Reservoir weld seam.

Reservoir to compressor O-ring.

Regulator to compressor O-ring.

Regulator boot-defective internal.O-rihg.

Diaphragm between first and second stage housings.

' Tightening through bolts may correct the leak.

Cover gasket and retainer screw. A few bubbles here

is not a leak. A continuous stream indicates defec-

tive compressor check valves.

Service valve.

Test gauge connections.

5.
Correct any leaks detected by either tightening

screws or replacing parts.

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-15

Control Valve

1.
Remove control valve unit from car.

2.
Clean exterior of control valve thoroughly.

3.
Connect test gauge and air pressure source to intake

adapter and open air pressure (80-110 psi).

4.
Submerge unit in water. No air should escape if

overtravel lever is in "neutral" position. If bubbles

escape from Superlift port, replace control valve.

5. Shut, off air pressure and detach test gauge from air

intake port. Plug intake port with Fill Valve,

J-21999 (female end).

6. Connect test gauge to Superlift port and open air

pressure.

7. With overtravel lever in "neutral" position no air

should escape. If bubbles escape from exhaust port,

replace control valve.

8. If air escapes around edge of cover plate, tighten

screws on replace gasket.
9. R(emove control valve from water. Actuate over-

travel lever to expel any water from unit.

10.
Sjiut off air pressure and remove line from Superlift

[

Lines and Fittings

1.
Eisconnect overtravel lever from link.

2.
Bold lever up in intake position for maximum Super-

lift inflation and release.

3.
iieak check all connections with a soap and water

splution.

[.

Superlifts

1.
disconnect lines and remove unit from car.

2.
ijiflate individually to 50-60 psi utilizing Fill Valves

jt-21999. Submerge in water and observe unit for

leaks.

3.
Install Superlifts.

SERVICE OPERATIONS

CONTROL VALVE

Removal

1.
Deflate system using service valve.

2.
Disconnect two air lines at leveling valve intake and

Superlift ports.

3.
Disconnect link from overtravel lever by removing

one nut and lock washer.

4.
Remove two screws securing leveling valve to frame

and remove leveling valve.

Installation

1.
Install control valve with two screws, with time delay

mechanism down.

2.
Secure link to overtravel lever with one nut and lock

washer. On all station wagons s'eries the link is se-

cured to the lower hole. On all other series cars

with standard springs, the link is secured to the up-

per hole.

3.
Connect air lines at control valve intake and Super-

lift port.

4.
Inflate reservoir to 140 psi or maximum pressure

available through service valve.

COMPRESSOR, RESERVOIR AND REGULATOR

Removal and Installation

1.
Disconnect air lines (manifold and air cleaner) at

compressor end;

2.
Disconnect pressure line at compressor head.

3.
From wheel side of fender skirt, remove two screws

from bracket on compressor end.

4.
Remove nut and washer from reservoir stud at

bracket and remove assembly from vehicle.

5. Remove compressor end mount bracket.

6. Reverse Steps 1-5 for installation, then leak check

fittings.

COMPRESSOR, RESERVOIR AND REGULATOR

Disassembly Into Major Components (Fig. 17)

The compressor is a precision-built mechanism. All

parts should be carefully handled and assembled. Take

care to prevent entrance of dirt or foreign matter. DO
NOT LUBRICATE as unit is designed to run dry.

1.
Remove compressor as described above.

2.
Remove three flexible mounts and three adapters.

3.
Remove reservoir retaining through bolt, cover re-

taining screw and cover gasket that secure cover and

gasket to first stage housing. Remove cover and

discard gaskets.

4.
Remove two regulator retaining screws, regulator

assembly and O-ring from second stage housing.

Discard O-ring.

5/ Remove three nuts at reservoir flange and two

through bolts that enter from flanged side of res-

ervoir. Separate reservoir and O-ring. Discard

O-ring.

6. Remove three compressor retaining through bolts

that secure second stage housing to first stage

housing.

7. Slide second stage (small diameter) housing straight

off piston.

8. Disconnect arm tension spring from swivel arm.

9. Remove arm pivot screw and actuating arm.

10.
Slide piston assembly straight out of first stage

housing.

Disassembly, Inspection and Assembly of Major

Components (Fig. 17)

Diaphragm

1.
Inspect diaphragm for holes, looseness or other de-

fects and replace if necessary.

2.
Remove diaphragm retainer with diagonal pliers and

discard.

3.
Remove diaphragm plate, diaphragm, second dia-

phragm plate and corprene washer from piston.

4.
Install new corprene washed, old plate, new dia-

phragm with outer lip toward second stage side,

(fig. 17) and second plate. Plates should be installed

so that lip on each plate faces away from diaphragm.

5. Use a 13/16 inch deep socket as a pilot for the new

diaphragm retainer. Press against the piston shoul-

der on first stage side, (fig. 18) to position dia-

phragm retainer. The wood blocks used in the illus-

tration are each 3/4" x 3/4" x 12".

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-16

Fig.
17 - Compressor, Regulator and Reservoir - Exploded View

1.
Regulator Assembly

2.
Adapter Assembly

3. Boot

4.
Sleeve

5. Piston

6. Spring

7. Retainer

8. "O" Ring

9. Valve Core

10..
Retainer, Screen

11.
Screen, Filter

12.
Adapter Assembly

13.
Adapter

14.
Valve Core

15.
"O" Ring

16..
Cap

17.
Screw, Regulator Retaining

18.
"O" Ring, Regulator to

Compressor
19.
Reservoir

20.
"O" Ring, Reservoir to

Compressor

21.
Thru Bolt, Reservoir

Retaining

22.,
Nut, Thru .Bolt Reservoir

23.
Thru Bolt, Compressor

Retaining

24.
Nut, Thru Bolt Compressor

25.
Compressor Assembly

26.
Housing, 2nd Stage

27.
Check Valve

28.
Spring

29.
Expansion Plug Retainer

30.
Housing 1st Stage

31.
Arm, Swivel

32.
Bushing

33.
Arm, Rocker .

34.
Pin, Rocker Arm Retaining
35.
Intake Valve

36,
Washer

37.
Spring, Intake Valve

Retaining

38.
Pin, Bushing

Retaining

39.
Piston Assembly

40.
Plate, Diaphragm

41.
Diaphragm

42.
Washer (.760-.765 I.D.)

43.
Retainer, Diaphragm

44.
Check Valve

45.
Spring

46.
Expansion Plug Retainer

47.
"O" Ring (.357-.367 I.D.)

48.
Seal (.569-.571)

49.
"O" Ring (.732-.742 I.D.)

50.
Seal (.943-.945)

51.
Piston
52.
Distributor Valve

53.
Bushing, Distributor Valve

54.
Washer (.160-. 163 I.D.)

55. Arm Assembly, Distributor

56. Screw

57. Spring, Valve Tension

58.
Bushing, Distributor Valve

Stop

59. Bussing, Arm Assembly

Stop

60.
Arm Actuating

61.
Spring, Arm Tension

62.
Screw, Arm Pivot

63.
Cover

64.
Gasket

65. Screw, Cover Retaining

66. Gasket, Cover

67. Mount, Flexible

68.
Adapter

NOTE: Position diaphragm retainer securely

to effect air tight seal against corprene washer.

Seals

1.
Inspect seals for evidence of excessive wear or

coring. If necessary replace seals and O-rings.

2.
Remove seals and O-rings from piston.

3.
Install new O-rings by rolling into groove. Relieve

any resulting twist.

4.
Install new seals using a piece of .020" shim stock,

(fig. 19). Make sure shim stock has no sharp edges

that may cut seal. Do not stretch seal more than
necessary to install. Seals should be installed so

they are not twisted.

Distributor Valve Mechanism and

Intake Valve (First Stage Housing)

NOTE: Actuate distributor valve with finger.

' Valve tension spring should press against dis-

tributor valve, holding it against either stop. If

valve action is not free and positive, it will be

necessary to rebuild using new parts in Distrib-

utor Valve and Arm Package. If action is free

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-17

and positive and upon disassembly there are no

damaged parts, parts may be re-used.

Disassembly

1.
Remove screw, washer, distributor arm assembly,

washer, and distributor valve bushing.

2.
Remove two arm assembly stop bushings and two

distributor valve stop bushings.

3.
Carefully remove distributor valve being careful not

to distort valve tension spring.

4.
Remove valve tension spring from housing boss,

again being careful not to distort valve tension

spring.

5.
Remove intake valve retaining spring, intake valve

and washer using pocket knife.

6. If necessary, remove rocker and swivel arms. Po-

sition pin for removal by prying with screw driver,

(fig. 20). Grip pin with water pump pliers and re-

move pin. Remove swivel arm, rocker arm and

bushings.

Cleaning and Inspection

1.
Clean all parts in clean solvent except distributor

arm assembly and blow dry with compressed air.

2.
Inspect distributor valve for cracks. Discard if

damaged.

3.
Inspect all other parts for wear or damage.

Assembly

1.
If removed, position bushings in first stage housing

and install rocker arm and swivel arm. Align hole

in rocker arm with swivel arm and install rocker

arm retaining pin, small end first.

NOTE: If distributor mechanism failed to

function properly or one or more parts were

found defective, use new parts in distributor

valve and arm package during remaining build-

up.

2.
Install washer on intake valve and install in first

stage housing with intake valve retaining spring.

3.
Install longer leg of valve tension spring into boss on

first stage housing being careful not to distort valve

tension spring.
020"
SHIM STOCK

SEAL

Fig.
19- Installing Seal

4.
Position distributor valve being careful not to distort

valve tension spring.

5.
Install two distributor valve stop bushings and two

arm assembly stop bushings.

6. Install distributor valve bushing, washer, distributor

arm assembly, and washer and secure with screw.

Tighten to 12 in. lbs.

NOTE: Do not install remaining parts at this

time as rocker arm must be free to permit en-

trance of piston into first stage housing.

Check Valve Replacement (Second Stage Piston)

1.
Pry out expansion plug retainer on second stage pis-

ton (with pointed tool) and remove spring and check

valve.

2.
Pour a small amount of clean solvent through bore

in piston and blow dry with compressed air. Check

valve seat should be smooth and clean.

3.
Install new check valve and spring.

%/DEEP SOCKET
ROCKER /

WHgggb
I

^RM-j|

111511

FIRST
m

H

STAGE
1 Mill IMW •

W

HOUSING

Fig.
18- Installing Diaphragm Retainer

Fig.
20 - Removing Rocker Arm ,

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-18

4.
Insert new expansion plug retainer and tap in until it

bottoms.

Check Valve Replacement

(Second Stage Housing)

1.
Pry out expansion plug retainer on second stage

housing (with pointed tool) and remove spring and

check valve.

2.
Glean second stage housing with clean solvent and

blow dry with compressed air. Check valve seat

should be clean and smooth.

3.
Install new check valve and spring.

4.
Insert new expansion plug retainer and tap in until

it bottoms.

COMPRESSOR, RESERVOIR AND REGULATOR

Assembly From Major Components

1.
Slide piston assembly straight into first stage (large

diameter) housing.

2.
Install actuating arm and secure to first stage

housing with arm pivot screw, tightening to 12 in.

: lbs. ;

3.
Connect arm tension spring to swivel arm.
9.

10.
Rotate piston in first stage housing to align elongated

hole in diaphragm with vent port in first stage

housing.

Install three compressor retaining through bolts that

secure second stage housing to first stage housing.

Housings will align one way only. Nuts are posi-

tioned in counterbores in second stage housing.

Tighten to 28 in. lbs.

Install new O-ring on second stage housing. Wash

inside of reservoir in clean solvent and blow dry

with compressed" air. Install reservoir on second

stage housing with three nuts, tightening to 28 in. lbs.

Install two reservoir retaining through bolts, tighten-

ing to 28 in. lbs. Through, bolt heads should-be posi-

tioned against reservoir. Leave out through bolt that

secures cover.

Install new O-ring on regulator and secure regulator

with two regulator retaining screws, tighten to 35 in.

lbs.
Service valve should be on same side as first

stage housing.

Install new gasket, cover, and secure with cover

retaining screw and new cover gasket. Tighten cover

retaining screw to 35 in. lbs. Install through bolt

so head is positioned against reservoir. Tighten

through bolt to 28 in. lbs.

Install three adapters and flexible mounts.

Proceed to compressor output test on car.

CHEVROLET CHASSIS SERVICE MANUAL