Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

Subject: Airliner 21K Lightweight Extra Duty
Rear Suspension Height Control Valve Installation
Models Affected: Fifteen Freightliner M2 vehicles (Model Year
2021) equipped with a single rear suspension leveling valve
manufactured in Santiago between January 22, 2020 and February
13, 2020
Our records indicate you are the owner of 15 specific vehicles; therefore DTNA is sharing the following
documentation with you.
The rear suspension height control valve and linkage installation on these 15 vehicles will need to be corrected
using the following work instructions.

Page 1

Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

Work Instructions
Subject: Airliner 21K Lightweight Extra Duty
Rear Suspension Height Control Valve Installation
Models Affected: Fifteen Freightliner M2 vehicles (Model Year
2021) equipped with a single rear suspension leveling valve
manufactured in Santiago between January 22, 2020 and February
13, 2020

Parts
Parts Required
Part Number
16-14494-002

Part Description
LINK KIT,5/16,345H

Quantity
1

Table 1, Parts Required

Work Instructions
1.

Park the vehicle on a level surface using a light application of the brakes, shut down the engine, set the
parking brake and chock the rear tires.

2.

Release the parking brake.

3.

Drain all the air from the air tanks.

4.

Locate the Airliner rear suspension height-control valve located on the inside of the left-hand frame rail just
rear of the drive axle.

5.

Remove any zip ties from the air lines or the valve that may restrict removal of the height-control valve
from the valve mounting bracket.

6.

Remove the nut and washer that attaches the existing height-control valve lever arm linkage to the lower
clip on the axle housing. See Fig. 1.

Page 2

Customer Advisory Letter

Daimler Trucks
North America LLC
03/06/2020
CAL FTL 32-003

1

3

2

4

5
03/05/2020

f321256

1. Mounting Bracket
2. Height-Control

4. Vertical Linkage
5. Lower Clip

Valve

3. Horizontal Control
Lever
Fig. 1, Height Control Valve Mounted on Rear of
Mounting Bracket

NOTICE
When removing or loosening a Barksdale height control valve from a mounting bracket, always hold the
valve-side mounting studs in place with an Allen wrench while loosening (or tightening) the nuts that
attach the valve to the bracket. Because the mounting studs are threaded into the valve body, loosening
the nuts without holding the studs can tighten the studs, which can crush the valve body and damage
the valve.
Conversely, tightening the nuts without holding the studs can back the studs out, causing a separation
of the two halves of the valve body, and possibly a leak.
7.

Remove the height control valve from the rear side of the mounting bracket:
7.1

Page 3

While holding the height control valve mounting studs in place with an Allen wrench, remove the nuts
and washers that attach the valve to the mounting bracket. See Fig. 2.

Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

2
1

3

03/03/2020

f321259

1. Drill Bit Locking Lever in Neutral Position
2. Allen Wrench
3. Wrench
Fig. 2, Holding the Mounting Studs in Place With an
Allen Wrench

7.2
8.

Remove the height control valve from the bracket and discard the linkage.

Relocate the height control valve to the forward side of the mounting bracket (see Fig. 3) :

Page 4

Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

2

3

1
4

03/05/2020

1. Mounting Bracket
2. Height-Control
Valve

f321257

3. Horizontal Control
Lever

4. Vertical Linkage

Fig. 3, Height Control Valve on the Forward Side of the
Mounting Bracket

8.1

While holding the height control valve mounting studs in place with an Allen wrench, install the nuts
and washers. Tighten the nuts 95 lbf·in (1100 N·cm). Do not over-tighten.

9.

Install the new linkage (part number 16-14494-002). See Fig. 3.

10.

Connect the linkage to the valve lever and lower clip on the axle housing. See Fig. 1 and Fig. 3.

11.

Start the engine and build the system air pressure to at least 100 Psi (690 kpa). Shut down the engine.

12.

Measure the suspension ride height at the left-hand side clamp group. See Fig. 4.
12.1 If the suspension ride height measures 111mm +/- 6mm (4.37" +/- 0.25"), the suspension ride height
is within the specification.
12.2 If the suspension ride height is not within this range, follow the Ride Height Adjustment procedure.

Page 5

Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

1

A

2

09/06/2019

A. Suspension Ride Height - 111
mm

f321249

1. Frame Bracket
2. U-Bolt
Fig. 4, Measuring the Suspension Ride Height

Ride Height Adjustment Procedure
1.

Disconnect the height control valve linkage at the lever stud.

2.

If the ride height is not correct, lift or lower the valve lever to adjust the height until it is at the proper ride
height.

3.

Lock the lever in neutral position with a 5/32-inch drill bit or nylon rod. See Fig. 5.

Page 6

Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

1

03/03/2020

f321258

1. Drill Bit
Fig. 5, Locking the Lever in a Neutral Position

NOTICE
When removing or loosening a Barksdale height control valve from a mounting bracket, always hold the
valve-side mounting studs in place with an Allen wrench while loosening (or tightening) the nuts that
attach the valve to the bracket. Because the mounting studs are threaded into the valve body, loosening
the nuts without holding the studs can tighten the studs, which can crush the valve body and damage
the valve.
Conversely, tightening the nuts without holding the studs can back the studs out, causing a separation
of the two halves of the valve body, and possibly a leak.
4.

While holding the height control valve mounting studs in place with an Allen wrench, loosen the nuts that
attach the valve to the mounting bracket. See Fig. 2.

5.

Adjust the position of the valve body until the lever still pinned in neutral position can connect to the linkage. Attach the linkage. The linkage rod should be vertical, and the valve body should now be in the correct position for the vehicle’s ride height.

6.

While holding the height control valve mounting studs in place with an Allen wrench, tighten the nuts 95
lbf·in (1100 N·cm). Do not overtighten, as that could damage the valve.

7.

Remove the pin or drill bit holding the height control lever in neutral position.

8.

Drive the vehicle unloaded for about 1/4 mile (1/2 km), then park the vehicle on a level surface using a
light brake application. Set the parking brake and chock the tires.

9.

Release the parking brake.

10.

Check the ride height of the vehicle again, measuring where indicated in figure.

11.

If the distance is within the acceptable range, the ride height is correctly set.

Page 7

Daimler Trucks
North America LLC

Customer Advisory Letter

03/06/2020
CAL FTL 32-003

12.

If the distance is not within the acceptable range, repeat the adjustment procedure.

Warranty
This procedure is warrantable only if the described condition exists and the repair is performed within the
applicable base or extended coverage warranty period. If a failure is not found, this procedure is considered
preventive and warranty does not apply.
Normal warranty applies. See Table 2 for OWL VMRS codes and labor allowance information. Enter this CAL
bulletin number in the claim story as you would do for a Service Bulletin warranty claim.

Primary Failed Part
16-14318-000

OWL VMRS Codes and Labor Allowance
Component Cause Code Correction
Description
Code
Code
016-009-027

28

996-F204A

Leveling valve R/R

Table 2, OWL VMRS Codes and Labor Allowance

Page 8

Time: Hours
0.6 HRS