X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

* May appear different than shown.

HAC Air Kit Components

8

OM-H719

HAC Air Kits
FIGURE 4-1

HAC REPLACEMENT PARTS
Outside Enclosure - Composite
R-009798

Electric Override Switch
R-009791

Spool Replacement Kit
R-009796-Z

R-009797-2
R-009797-3

Pressure Protection Valve
R-009689

R-009797
R-009797-4

Quick-Exhaust Valve
R-004348-1

Reverse Down & Lock Valve
HAC-RSI, HAC-RCO
& HAC-RSO R-009790-1

Reverse Caster Valve
HAC-ASI, HAC-ACO
& HAC-ASO R-010028

Reverse Lift & Lock Valve
HAC-LSI, HAC-LCO
& HAC-LSO R-009790

Solenoid
Valve Nut
R-009797-1

Solenoid
Valve Nut
R-009797-1
Gauge Bracket
R-009793-Z

Solenoid Valve Assembly
HAC-MCA prior to 04/17
HAC-MSO
R-009797-2
R-009797-3
Solenoid Valve Assembly & Nut
Steerable & Outside R-009797

Gauge, Hose &
Bracket Assembly
R-009793

Air Module
HAC-NSI
HAC-MSO
HAC-USO/SSI

Regulator Nut
R-009794-Z

R-009796-1
R-009796-2
R-009796-3

Push / Pull, Nut & Knob Assembly
R-009795

Push / Pull Knob
R-009795-K

In-Line Filter
R-013282

Regulator & Nut Assembly
R-009794

Push / Pull Nut
R-009795-Z

Face Plate Inside
HAC-USO

R-009792
R-009192-1

FIGURE 4-2

INSIDE-MOUNTED AND OUTSIDE-MOUNTED CONTROLLERS
Inside-Mounted Front View
HAC-SSI, NSI, LSI, RSI, ASI

Inside-Mounted Back View
Non-steerable HAC-NSI
Red-Ride Springs
Blue-Lift Springs

Green-Supply
Outside-Mounted Composite Box
(Maryland Specification)
HAC-MSO - Includes schrader
valve to verify
air pressure

OM-H719

Inside-Mounted Back View
Steerable HAC-SSI
To Reverse Signal and
To Good Vehicle Ground

Yellow-Exhaust

Outside-Mounted Composite Box
HAC-UCO, LCO, RCO & ACO
HAC-USO, LSO, RSO & ASO

9

Outside-Mounted Stainless Box
HAC-UCO, LCO, RCO & ACO
HAC-USO, LSO, RSO & ASO

HAC Air Kit Components

HAC Air Kits
FIGURE 4-3

OPTIONAL COMPONENTS
Single-panel Mount Bracket R-009800-1
For inside the cab

Double-panel Mount Bracket R-009800-2
For inside the cab

6.5"

L-shape Panel Mount Bracket R-005771
For mounting the control panel on the
side of the center console box
(Single Panel application only)

6.5"
2"
4.31"

6.625"

7.81"

Quick-Exhaust Valve R-004348
Two (2) used per axle

HAC Air Kit Components

10.125"

7.81"

7.5"

Brake Release Valve R-001994

10

OM-H719

HAC Air Kits
SECTION 5

Installation
INSTALLATION INSTRUCTIONS
It is important to read and understand this entire installation instruction and all recommended safety precautions prior to performing any installation, service or maintenance of the product. Ensure the air control
components match the desired lift axle application.
1. Refer to the Plumbing and Wiring Diagram in Section 6 of this publication.
2. Mount the air control valve inside or outside the cab as required.
3. Route the air lines required for all kits, see Figures 5-1 and 6-1 (Air and Electrical Diagram):
a. Route an air line from the GREEN PORT to the lift axle supply air tank. Install the pressure protection
valve (R-009689), and in-line air filter (R-013282) both listed in Figure 4-1 oriented with the arrow
pointing in the direction of flow. Install the in-line air filter (R-013282) oriented as shown in Figure 5-2.
b. Route an air line from the RED PORT to the lift axle ride springs. Install the Quick-Exhaust valve
(R-004348-1), listed in Figure 6-3, acting as a tee to both ride springs. Mounting the Quick-Exhaust
valve close to the tanks will improve the axle’s lift time.
c. Route an air line from the BLUE PORT to the lift axle lift springs using a T-fitting as necessary.
d. Route a small length of tubing from the YELLOW PORT to a protected area to reduce the chance of
debris entering the valve. For Inside-Mounted controls, routing the exhaust hose outside of the cab
will reduce noise.
FIGURE 5-1

AIR LINE PORTS

RED (3/8") to Ride Air Spring, D.O.T. Approved

BLUE (3/8") to Lift Spring, D.O.T. Approved

GREEN (3/8") to Supply - Air tank, D.O.T. Approved
YELLOW (3/8") to Exhaust, D.O.T. Approved

4. If equipped with a two-wire solenoid valve, connect one (1) lead to a good vehicle ground and the
other to a good reverse signal such as the reverse light wiring. DO NOT connect solenoid to reverse
signal if equipped with Electric Override Switch (R-009791), see Figure 6-4. Move on to the next step.
5. If equipped with the Electric Override Switch (R-009791), refer to the Electric Override Switch Diagram
in Section 6 and make the following connections, see Figure 6-4.
NOTE

If equipped with a non-steerable lift axle or an air control kit that defaults to lift such as HAC-MCA or
HAC‑MSO, special wiring instructions are included.
a. Connect A red wire from Relay Terminal 86 to a good reverse signal. For non-steerable lift axle
applications, do not connect. Cap off this wire to avoid grounding.
b. Connect B white wire from Relay Terminal 30 to the open lift axle control solenoid wire.
c. Connect C red wire from Relay Terminal 87a to the toggle switch and another from the open toggle
switch terminal to a +12v DC power source. An Ignition “Accessory On” power source is recommended.
d. Connect D black wire from Relay Terminal 85 to a good vehicle ground.
e. Connect E red wire from Relay Terminal 87 to a +12v DC power source. An Ignition “Accessory On”
power source is recommended. For non-steerable lift axle applications do not connect. Cap off this
wire to avoid grounding. For default to lift air control kits including HAC-MCA and HAC-MSO do not
connect. Cap off this wire to avoid grounding.

OM-H719

11

Installation

HAC Air Kits
6. HAC-LSI / LCO / LSO specific instruction:
a. Find a position inside the frame or body to mount the Reverse Lift & Lock valve (R-009790).
Preferably near the lift axle.
b. Add a Tee in the Supply line and route an air line to the Reverse Lift & Lock Port 1.
c. Add a Tee in the Lift line and route a line to the Reverse Lift & Lock Port 3.
d. Route an air line from the Reverse Lift & Lock Port 2 to the Lock Straight chambers mounted on the
axle using a Tee as necessary.
7. HAC-RSI / RCO / RSO specific instruction:
a. Find a position inside the frame or body to mount the Reverse Down & Lock valve (R-009790-1).
Preferably near the lift axle.
b. Add a Tee in the Supply line and route an air line to the Reverse Down & Lock Port 1.
c. Route an air line from the Reverse Down & Lock Port 2 to the Lock Straight chambers mounted on
the axle using a Tee as necessary.
d. Follow the diagram on Electric Override Switch, see Figure 6-4.
8. HAC-ASI / ACO / ASO specific instruction:
a. Find a position inside the frame or body to mount the Reverse Caster valve (R-010028). Preferably
near the lift axle.
b. Add a Tee in the Supply Line and route an air line to the Reverse Caster valve Port 1.
c. Add a Tee in the Lift Line and route a line to the Reverse Caster end port 90-degree fitting.
d. Route an air line from the Reverse Caster Port 2 to the Reverse Caster chambers mounted on the
suspension hanger using a Tee as necessary.
e. Follow the diagram on Electric Override Switch, see Figure 6-4.

INSTALLATION TIPS
USE A FILTER RATED TO AT LEAST 40 MICRONS ON THE INCOMING (GREEN) SUPPLY AIR LINE TO THE AIR
CONTROL VALVE. ANYTHING LESS COULD ALLOW DEBRIS AND PARTICULATES THROUGH, WHICH COULD BE
DETRIMENTAL TO THE AIR CONTROL VALVE COMPONENTS.
FIGURE 5-2

■■

Use only air brake tubes that conform to S.A.E. J844
and ensure all tubes are free from kinks.

■■

Ensure that the minimum bend radii are achieved on
all tubes prior to assembly.

Filter installation
to Air Supply

RECOMMENDED MINIMUM BEND RADII:
●●

¼" Tube – 1.0 inch
⁄ " Tube – 1.5 inches

●● 3 8

Installation

●●

½" Tube – 2.0 inches
⁄ " Tube – 2.5 inches

●● 5 8

■■

Use only dedicated tube cutters when preparing tube
ends for insertion into push-in fittings.

■■

Ensure tube ends are square, free from all damage, and
clean.

■■

Ensure tube is fully inserted into fittings (tube ends are
pushed past both the grip ring and the sealing O-ring).

■■

Ensure fitted panels have enough free length of tube to
ensure the tube in the fittings is not under any tension.

■■

Crimp wires for all electrical connections into the butt
connectors provided using an appropriate crimp tool.

■■

Ensure there is sufficient free electrical cable to prevent wires and connections from being under tension.
12

OM-H719

HAC Air Kits
SECTION 6

Plumbing & Wiring Diagram
FIGURE 6-1

OM-H719

13

Plumbing & Wiring Diagram

HAC Air Kits
FIGURE 6-2

REVERSE VALVES

To Reverse Signal and
Good Vehicle Ground
Port 1
From Supply

Port 2
To Lock Chambers
From
Lift Springs
Reverse Lift & Lock Valve
HAC-LSI, LCO & LSO R-009790

Port 3
Exhaust

Port 1
From Supply

Port 2
To Lock Chambers
Reverse Down & Lock Valve
HAC-RSI, RCO & RSO R-009790-1

To Reverse Signal and
Good Vehicle Ground

From Lift Spring Line
(Blue)
Port 2
To Reverse Caster Chambers

Port 1
From Supply

Reverse Caster Valve
HAC-ASI, ACO & ASO R-010028
FIGURE 6-3

PLUMBING DIAGRAM
Quick-Exhaust Valve R-004348-1
One (1) supplied with all air kits, can be
bolted to vehicle frame or crossmember

Optional Quick-Exhaust Valve R-004348
Two (2) Alternative mounts ride spring
air inlet port
Lock Straight /
Reverse Caster
Air Chambers

To Vehicle Air System
Lock Straight Chambers
Installed
To Brake Signal
To Air Kit Supply
To Ride Springs
To Reverse Valve
To Lift Spring

Plumbing & Wiring Diagram

14

OM-H719

HAC Air Kits
FIGURE 6-4

ELECTRIC OVERRIDE SWITCH

E

One (1) Toggle Switch
One (1) Female Spade Receptacle

White Wire
16 AWG.

B
N.C. 87a
30

A

86

Positive Wire
(Main Supply)

C

Red Wire
16 AWG.

N.O.

Red Wire
(Terminal 87)
16 AWG. +12v DC

87

85

B

A Red Wire
(Terminal 86)
16 AWG.
From Reverse Signal

E
D

C

White Wire
(Terminal 30)
16 AWG.