Countries: UNITED STATES Document ID: 1K0300074

o Availability: ISIS, NotSIR Revision: 0
Major System SPRINGS AND SUSPENSION Created: 3/1/2021
Current Language: English Last Modified: 3/11/2021

Knowledge Base Other Languages: NONE Author: David Horner
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Title: CV Air Spring Failure in Roll-Back / Wrecker-Hook Applications

Applies To: Vehicle Applications: Roll-Back & Wrecker-Hook (Recovery) built before 11/9/20 with
feature codes 14TBL or 14TBM or 14TDG IROS Suspension and with 0014899 Suspension air control
valve pressure release in cab SUSPENSION, REAR, AIR, SINGLE

CHANGE LOG

Please refer to the change log text box below for recent changes to this article:

DESCRIPTION

Navistar has identified a failure condition where operators or technicians may report air leaking from rear suspension air
spring(s).

In normal application conditions when switching feature code 0014899 to dump, the height control valve receives command to
exhaust air and not refill the air springs until receiving fill command. When the rear air springs do not have air the frame rail will
rest on the axle stops. The air springs are not pinched between the top and bottom plates (Figure 1).

In Roll-Back & Wrecker-Hook (Recovery) applications built before 11/9/20 with IROS suspension feature codes and suspension
dump feature code 0014899, air spring failure may occur under certain circumstances when the air spring is pinched between
the top and bottom plate. Body builder designs may not restrict the range of motion for hydraulic body controls which cause the
frame rail to rise from the axle stops and the air springs to be stretched open & collapse without air pressure (Figure 2). The
operator retracts the hydraulics toward the stowed position, the frame rail lowers back onto the axle stop and pinches the
collapsed air spring (Figure 3). A pinched air spring may leak air (Figure 4). In some cases, the rubber may also be dislodged
from the bottom spring plate (Figure 5).

Navistar has taken the following actions in production as result of failures
-Reduced the overall height of air spring- Effective 3/16/20
-Reduced the maximum extended length of the rear shock absorber- Effective 9/28/20
-Blocked suspension dump feature code in Roll-Back & Wrecker-Hook (Recovery) applications- Effective11/9/20
0014899- SUSPENSION AIR CONTROL VALVE Pressure Release Control In Cab

[Figure 1: Normal view of air spring when suspension is dumped

[Picture taken after suspension has fully dumped

Figure 2: Collapsed Suspension Air Spring

Picture taken when body builder hydraulic controls are operated
while suspension is dumped

NORMAL)

Figure 3: Pinched Suspension Air Spring (CONDITION IS NOT

Picture taken when body builder hydraulic controls are operated
back towards the stowed / transport position while suspension is
dumped

[Figure 4: Torn Air Spring

Picture taken after air spring has been removed from vehicle to
inspect for leaking air

|

Figure 5: Damaged Air Spring

Picture taken after air spring has been removed from vehicle to
inspect for leaking air

SYMPTOM(s)

Diagnostic Trouble Code(s) & Dashboard Indicator Light(s):

DTC/Light

Description
N/A

Customer Observations or Concerns:

¢ Failed rear suspension air spring in Roll-Back (Recovery)& Wrecker-Hook (Recovery) applications
* Collapsed, pinched, torn

SPECIAL TOOL(s) / SOFTWARE

Tool Description Tool Number

N/A

Comments Instructions

SERVICEPARTS INFORMATION

Kit Description Part Number Quantity Notes
Required

SPRING, AIR RIDE GY1R10171 2 3890365C1

ABSORBER, SHOCK ABSORBER 4214011C2 2

DIAGNOSTIC STEP(s)

Refer to Repair Steps below

REPAIR STEP(s)

1. Park vehicle on dry, level ground, install wheel chocks, set parking brake, and place transmission in Park

2. Replace both rear air springs and both rear shocks with the part numbers provided in this document using CV Technician
Manual (Service & Diagnostic) 0001111853

3. Remove wheel chocks, repair complete

WARRANTY INFORMATION

Warranty Claim Coding: