SB-10044338-3408

Service Program
Trucks

Mack Trucks, Inc.
Greensboro, NC USA

This Service Program replaces,
“PI0787, Transmission Cooler Line
O-Ring”, PV729–PI0787 (USA53340)
dated (05/2012).

Date

Group

No.

Release

Page

6.2012

491

787

02

1( 8 )

Transmission Cooler Line O-Ring
CHU, CXU, GU, TD

PI0787, Transmission Cooler Line O-Ring
(June 2012)
Certain MACK trucks built between January 01, 2012 and March 05, 2012 may have
been assembled with an incorrect o-ring installed on the transmission cooler line fittings.
The transmission cooler line fittings are located at the bottom of the radiator where the
transmission cooler lines connect to the transmission cooler, and where the lines connect
to the transmission. The incorrect o-ring may not seal properly, causing transmission fluid
loss and/or premature transmission damage.
Trucks built after March 05, 2012 were assembled with a replacement o-ring on the
transmission cooler line fittings. A white dot on the shoulder of the fitting cap indicates a
replacement o-ring was installed during assembly. See figure below. Visually inspect the
truck for a white dot on the shoulder of the fitting cap. If the white dot is visible, only an
inspection for the white dot is required. If the white dot is not visible on the fitting cap,
replace the existing o-ring with a new green o-ring (part number 21866819). See the o-ring
replacement procedure on page 2.
Note: This bulletin does not apply to MACK Trucks Australia.

W4072905

Transmission Cooler Line Fitting Components

PV729-PI0787

Item #

Part Number

Description

1

21866819

O-Ring

2

85129501

Locking Collar

3

85131659

Cap

4

N/A

Visual Inspection Mark (White Dot)
USA54119

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

Procedure
You must read and understand the precautions and guidelines in Service Information,
group 40, "General Safety Practices, Engine" before performing this procedure. If you
are not properly trained and certified in this procedure, ask your supervisor for training
before you perform it.
1 Apply parking brake and place shift lever in neutral.
2 Raise hood or cab.
3 Disconnect all cables from the negative (ground) battery terminals to prevent personal
injury from electrical shock and prevent damage to electrical components.
4

Inspect the transmission cooler line fittings cap for the white dot at the transmission
and the radiator.
Note: If a White Dot is visible on the cap, the inspection is complete. If the White Dot is
not visible on the cap, continue onto step 5 and replace the four o-rings for the radiator
and the transmission fittings.

W4072906

5 Using a screwdriver or suitable instrument, remove the Sure-Fit clip (20733354).
Note: Use a suitable container to catch any transmission fluid during this procedure.

W4072907

Page
2( 8 )

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

6 Using a screwdriver or suitable instrument, disengage the cap.

W4072908

7 Pull the cap back until it rests against the stop shoulder as shown in the figure below.

W4072909

Page
3( 8 )

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

8 Locate the 15 mm (0.6 in) transmission line removal tool (part number 85108826) around
the protruding plastic lugs of the locking collar.
Note: Ensure that the internal shoulders of the tool are nearest to the female cavity
face and flat and/or parallel to it.

W4072910

9 Using one hand close the tool jaws around the protruding plastic lugs, compress the
plastic lugs, pull back on the fitting with the other hand, and disconnect the transmission
cooler line fitting.

W4072911

Page
4( 8 )

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

10 Release the transmission line removal tool and store for future use.
11 Clean both the male and female transmission cooler line fittings of any debris or corrosion.
12 Remove the existing o-ring.
13 Install new green o-ring (part number 21866819).
Note: Lubricate the new o-ring with transmission fluid before installation to prevent
binding when the hose is reinserted into the fitting.

W4072912

14 Ensure that the cap is retracted all the way back to the stop shoulder.
Note: Prior to assembly, be sure that all surfaces are clean to ensure proper connection.

W4072913

15 While holding the transmission cooler line, connect the fitting and push until the locking
collar snaps into position.

W4072914

Page
5( 8 )

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

16 Slide the cap forward until it snaps onto the protruding lugs of the locking collar.
Note: To ensure a good connection, the cap must be flush with the front face of the
female cavity and no part of the locking collar is visible.

W4072915

17 Install the Sure-Fit clip as shown in figure below.
Note: If there is difficulty installing the Sure-Fit clip, inspect the transmission cooler
line for a good connection.

W4072916

18 Reconnect all previously removed cables to the negative (ground) battery terminals.
19 Check transmission fluid levels and replenish if needed.
20 Lower hood or cab.

Page
6( 8 )

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

Note: To signify that the campaign has been completed, using a permanent-type marker
(such as a Sharpie®) to write the campaign number (PI0787) and completion date in the
spaces provided on the Campaign Completion label located inside the cab as shown in the
illustration below. If a label is not already affixed inside the cab, apply a label (part No.
TS897) and supply the information as required. Campaign Completion labels are available
in packs of 50 and can be ordered by faxing a completed BR313 to Pacesetters Business
Services at 610-264-9465.

W8034103

Page
7( 8 )

Mack Trucks, Inc.
Service Program

Date
6.2012

Group

No.

Release

491

787

02

Reimbursement
This repair is covered by an authorized Service Program. Reimbursement is
obtained through the normal claim handling process.
Claim Type (used only when uploading from the Dealer Bus. Sys.)

B

Recall Status
Vehicle inspected, repair not required

1- Inspected OK

Vehicle repaired per instruction

2- Modified per
instruction

Labor Code
Primary Labor Code
Time for inspection

3295J-01-96
0.3 hrs.

Primary Labor Code
Time for inspection and replacement of the o-ring

3295K-01-96
0.4 hrs.

Time to take charge and determine campaign status

101AA–0A–00
0.3 hr.

Causal Part

20787860

Authorization Number

PI0787

Expiration Date

11-MAY-13

Note: Take Charge Time is not included in the Labor Code for this operation. Take charge
may be eligible but can only be used once per repair visit. If vehicle is having other warranty
repairs performed, take charge should be charged to the warranty repair, otherwise take
charge can be charged to this service program.

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