Allison Transmission Cooler Quick-Connect Fittings

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Allison Transmission Cooler Quick-Connect
Fittings
20-018
Shuttle Bus
Recreational Vehicle
School Bus
Walk-In Van
> S2

Freightliner Custom
Chassis Service Bulletin

General Information
On S2 chassis equipped with an Allison transmission, the Behr/Mahle cooling modules use quick-connect fittings
to attach the transmission cooler lines to the radiator. Some of the fittings may leak, which can cause the
transmission to lose fluid. Use the procedure in this bulletin to inspect and repair the connections.

IMPORTANT: This procedure is warrantable only if the quick-connect fittings that attach the
transmission cooler lines to the radiator are leaking fluid, and the repair is performed within the
applicable base or extended coverage warranty period. If the quick-connect fittings do not leak, this
procedure is considered preventive and warranty does not apply.
NOTE: This procedure applies only to vehicles equipped with a Cummins B-Series engine and an
Allison transmission.

Parts
The parts are available from the PDCs. See Table 1 and Fig. 1 .
Parts
Part Number

Description

Qty.

23-12485-175

Clamp

2

07-24833-000

Collar

2
Table 1, Parts Required

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Allison Transmission Cooler Quick-Connect Fittings

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Fig. 1, Clamps and Collars

Procedure
1.

Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.

2.

Inspect the transmission cooler lines where they connect to the radiator and determine if they have the
original plastic cap and spring clip as installed from the factory (see Fig. 2 ) or if a hose clamp has been
installed as a temporary containment (see Fig. 3 ).
If the hose clamp containment has already been installed, remove the hose clamps, discard them, and go to
step 4.

Fig. 2, Cooler Line Connection with Original Plastic
Cap and Spring Clip

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Allison Transmission Cooler Quick-Connect Fittings

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Fig. 3, Cooler Line Connection with Hose Clamp
3.

Remove the plastic retaining cap by gently prying it away from the fitting with a flat bladed screw driver. Slide
the plastic cap back onto the metal portion of the transmission cooler line. See Fig. 4 .

4.

Using a pick or small screwdriver, remove the metal retaining clip. See Fig. 5 . Set the clip aside.

Fig. 4, Removing the Plastic Cap

Fig. 5, Removing the Spring Clip
5.

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Allison Transmission Cooler Quick-Connect Fittings

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On the driver-side connection, install one half of the collar assembly on the radiator fitting, as shown in Fig. 6 .
While holding the collar half in place, gently pull the hose back (toward the rear of the vehicle) until it stops
against the collar (this will help make installation of the other collar half easier).

NOTE: The inner diameter of the collar has a machined ridge that will locate in the groove where the
metal spring clip was installed.
6.

Install the other half of the collar. Unscrew the constant-torque clamp so that it can be wrapped around the
line without removing the line, then wrap it around the collar halves as shown in Fig. 7 . Orient the clamp as
shown, making sure it fits in the groove machined into the outer diameter of the collar. Tighten the clamp 55
to 65 in·lbs (620 to 735 N·cm).

Fig. 6, Half of Collar Assembly Installed

Fig. 7, Collar and Clamp Installed
7.

Repeat the process for the passenger-side connection. Orient the clamp as shown in Fig. 8 . Tighten the
clamp 55 to 65 in·lbs (620 to 735 N·cm).

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Allison Transmission Cooler Quick-Connect Fittings

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Fig. 8, Passenger-Side Connection
8.

Start the vehicle and check the connections for leaks. If no leaks are found, cut away and discard the plastic
caps (if applicable) using diagonal cutters.

Warranty
This procedure is warrantable only if the quick-connect fittings that attach the transmission cooler lines to the
radiator are leaking fluid, 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 service
bulletin number in the Service Bulletin # field.
OWL VMRS Codes and Labor Allowance
Primary Failed
Part
BHT W8274001

Component
Code
026-013032

Cause
Code
03

SRT
Code
3705002A

Description
COLLAR AND CLAMP, TRANS OIL
COOLER, INSTALL (SB20-018)

Time:
Hours
0.2

Table 2, OWL VMRS Codes and Labor Allowance
Freightliner Custom Chassis Service Bulletin , 05/27/2019

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