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

6.

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

7.

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

8. Store electrical connection inside the enclosure (Outside-Mounted kits only).
9. When installing the pressure protection valve, ensure to orient with the vent hole facing down.

FIGURE 4-1

MASTER CONTROL AND SLAVE ASSEMBLY
INSTALLATION
1. Refer to Figure 5-1 in the Plumbing and Wiring Diagram
Section of this publication.
2. Install exhaust fittings and tubes (provided loose) onto slave
assembly, see Figure 4-1.
3. Mount slave assembly to vehicle frame, locating near the lift
axle for optimal plumbing.
4. Mount master control assembly in preferred location.
NOTE

If Controls are Inside-Mounted – Regulator panel nut is installed
loosely by Hendrickson for ease of installation. Tighten once the
master control is positioned in the mounting bracket.
Exhaust Fittings
and Tubes

OM-H817

9

Installation

LC Auxiliary Lift Axle Control Kits
PNEUMATIC COMPONENTS
1. Route the airlines required for all kits, see Figures 4-2 and 4-3 for individual port locations.
a. Route airline from Supply Air Tank to GREEN PORT on master control and to GREEN PORT on slave
assembly.
b. Install the pressure protection valve (R-017521-13) as shown in Figure 5-1.
c. Route airline from PURPLE PORT on master control to slave assembly for regulated airline.
d. Route airline from BROWN PORT on master control to slave assembly for piloted airline.
e. Route airline from BLUE PORTS on slave assembly to lift springs.
f. Route airline from RED PORTS on Quick-Exhaust Valve on slave assembly to ride springs.
FIGURE 4-2

MASTER CONTROL
Inside-Mount LC-NSI

Solenoid wiring One to ground and one to either
Reverse or R-017521-05 electric switch relay

Inside-Mount LC-SSI

PURPLE
(3/8" D.O.T. Approved)
Connect regulated air
from master to slave

GREEN
(3/8" D.O.T. Approved)
Connect to supply air tank
BROWN (¼" D.O.T. Approved)
Connect piloted air from
master to slave
Outside-Mount

Outside-Mount

FIGURE 4-3

SLAVE ASSEMBLY
PURPLE
(3/8" D.O.T. Approved)
Connect regulated air from
master to slave
BROWN
(¼" D.O.T. Approved)
Connect piloted air from
master to slave

RED
(½" D.O.T. Approved)
Connect Quick-Exhaust Valve
to ride springs (2 ports)

GREEN
(3/8" D.O.T. Approved)
Connect to supply air tank

BLUE (3/8" D.O.T. Approved)
Connect slave assembly
to lift springs (2 ports)

Installation

10

OM-H817

LC Auxiliary Lift Axle Control Kits
ELECTRICAL COMPONENTS
1. 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-017521-05), see Figure 4-4. Move on to the Step 2.
2. If equipped with the Electric Override Switch – refer to the Plumbing and Wiring Diagram in Section
5 and make the following connections, see Figure 4-4.
NOTE

If equipped with a Non-Steerable lift axle or an air control kit that lifts the axle to the up position when the
vehicle is powered off, such as LC-MCA or LC-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 air control kits that lift the axle to the up position when the vehicle
is powered off including LC-MCA and LC-MSO DO NOT connect. Cap off this wire to avoid grounding.
3. LC-LSI / LCO / LSO specific instruction:
a. Find a position inside the frame or body to mount the Reverse Lift & Lock Valve (R-017519-00).
Preferably near the lift axle.
b. Add a Tee in the Supply Line and route an airline to the Reverse Lift & Lock (N.C. Port).
c. Add a Tee in the Master / Slave Pilot Line and route an airline to the Reverse Lift & Lock (N.O. Port).
d. Route an airline from the Reverse Lift & Lock (COM Port) to the Lock Straight Chambers mounted
on the axle using a Tee as necessary.
4. LC-RSI / RCO / RSO specific instruction:
a. Find a position inside the frame or body to mount the Reverse Down & Lock Valve (R-017520-00),
preferably near the lift axle.
b. Add a Tee in the Supply Line and route an airline to the Reverse Down & Lock (IN Port).
c. Route an airline from the Reverse Down & Lock (CYL Port) to the Lock Straight Chambers mounted
on the axle using a Tee as necessary.
d. Follow the diagram on Electric Override Switch, see Figure 4-4.
5. LC-ASI / ACO / ASO specific instruction:
a. Find a position inside the frame or body to mount the Reverse Caster valve (R-017518-00).
Preferably near the lift axle.
b. Add a Tee in the Supply Line and route an airline to the Reverse Caster Valve (IN Port).
c. Add a Tee in the Lift Line and route an airline to the Reverse Caster (PILOT Port).
d. Route an airline from the Reverse Caster (COM Port) 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 4-4.

OM-H817

11

Installation

LC Auxiliary Lift Axle Control Kits
FIGURE 4-4

ELECTRIC OVERRIDE SWITCH

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

One (1) Toggle Switch
One (1) Female Spade Receptacle
White Wire
16 AWG.

C

Red Wire
16 AWG.

B
N.C.

*87a

*30

N.O. *87

A

*86

Positive Wire
(Main Supply)

*85

Red Wire
16 AWG.

B White Wire
(Relay Terminal 30)
16 AWG.
To Solenoid Valve

E
D

NOTES

C

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

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

D

Black Wire
(Relay Terminal 85)
16 AWG. GROUND

1. Electric Override Switch is supplied with all Outside-Mounted air kits.
Red Wire
16 AWG.

2. For LC-MCA and LC-MSO air kits, remove the red wire E and discard.

Black Wire
16 AWG.

3. For non-steer, DO NOT connect wires A (Relay Terminal 86) or
wire E (Relay Terminal 87). This disables lift in the reverse function
but maintains the Lift Override function.

NOTE
* Relay Terminal

REVERSE CONTROLS
FIGURE 4-5

FIGURE 4-6

*Reverse Down & Lock Valve Assembly R-017520-00

*Reverse Lift & Lock Assembly R-017519-00
From Tee in Master /
Slave Pilot Line (N.O. Port)

To Ground

To Lock Chambers
(COM Port)

From Tee in
Supply Line
(N.C. Port)

From Tee in
Supply Line
(IN Port)

From Reverse Signal

To Lock Chambers
(CYL Port)

FIGURE 4-7

*Reverse Caster Assembly R-017518-00

From Tee in
Supply Line
(IN Port)

From Reverse
Signal
Installation

From Tee in
Lift Line
(PILOT Port)

To Ground

To Reverse Caster
Chambers (COM Port)

12

NOTE
*Orient filters downward

OM-H817

LC Auxiliary Lift Axle Control Kits
SECTION 5

Plumbing & Wiring Diagram
FIGURE 5-1

OM-H817

13

Plumbing & Wiring Diagram

LC Auxiliary Lift Axle Control Kits
SECTION 6

Suspension Operation
RAISING YOUR LIFT AXLE
1. If the vehicle is already running, please proceed to Step 6.
2. Set parking brake of truck.
3. Turn your vehicle ignition to on position.
4. Press start switch and release when engine is started.
5. Allow the vehicle to idle until the vehicle air system pressure has reached the compressor cut-out pressure (usually 120 psi).
6. If controls are Inside-Mounted – Move the switch to LIFT position to immediately lift the axle.
7. If controls are Outside-Mounted – Ensure the vehicle is stopped and parking brake is set. Exit the
vehicle, go to air control enclosure and open it. Move the push / pull valve to LIFT position to immediately lift the axle.
■■

Equipped with Electric Override Switch Part No. R-017521-05 – Turning the switch to the ON
position will override the push / pull knob and raise the axle. Turning the switch off will immediately
redeploy the axle. Likewise terminating power to the switch, such as turning the vehicle off, will
immediately redeploy the axle.

8. Visually confirm the axle is lifting.
NOTE

Vehicle system air pressure may drop during suspension lifting process.
9. Lift axle should be completely lifted when the vehicle’s air system pressure returns to the air compressor cut-out point (usually 120 psi).
10. Hendrickson recommends raising the lift axle when not in use and when off-road.

LOWERING YOUR LIFT AXLE
1. If the vehicle is already running, please proceed to Step 6.
2. Set parking brake of truck.
3. Turn your vehicle ignition to the ON position.
4. Press start switch and release when engine has started.
5. Allow the vehicle to idle until the vehicle air system pressure has reached the compressor cut-out (usually 120 psi).
DO NOT LOWER LIFT AXLE WHILE THE VEHICLE IS MOVING IN REVERSE OR TRAVELING AT MORE THAN 15 MPH.
FAILURE TO DO SO CAN CAUSE COMPONENT DAMAGE.

6. If the controls are Inside-Mounted – Move the switch to LOWER position to immediately lower the axle.
7. If the controls are Outside-Mounted – Ensure the vehicle is stopped and the parking brake is set. Exit
the vehicle, go to air control enclosure and open it. Move the push / pull valve to LOWER position to
immediately lower the axle.
■■

Equipped with an Electric Override Switch Part No. R-017521-05 – If the axle fails to deploy,
toggle the override switch in the cab to the OFF position.

8. Using the regulator, adjust air pressure on the gauge to the appropriate air pressure for vehicle load
conditions. See air pressure load charts in the applicable Hendrickson Auxiliary Lift Axle Owner’s Manual
Literature No. OM-H754 (Steerable) or Literature No. OM-H757 (Non‑Steerable).
NOTE

Air system pressure may drop during suspension lowering process.
9. Lift Axle should be completely lowered and supporting the pre-determined load when system air
compressor cut-out point is reached (usually at 120 psi).

Suspension Operation

14

OM-H817

LC Auxiliary Lift Axle Control Kits
SECTION 7

Replacement Parts List
1a

1b

1c

1d

1e

1f

LIFT AXLE MASTER ASSEMBLY
ITEM

1

OM-H817

DESCRIPTION

PART NUMBER

QTY.

a

LC-NSI or RSI

R-017512-00

1

b

LC-SSI, LSI or ASI

R-017513-00

1

c

LC-UCO, LCO, RCO or ACO

R-017514-00

1

d

LC-USO, LSO, RSO or ASO

R-017515-00

1

e

LC-MSO

R-017516-00

1

f

LC-MCA

R-017517-00

1

15

Replacement Parts List

LC Auxiliary Lift Axle Control Kits

2

3

4

5a

6

7

9

10

5b

8

ITEM

DESCRIPTION

PART NUMBER

QTY.

2