FSB 511-008

Field Service Bulletin
Trucks
Mack Trucks, Inc.
Greensboro, NC USA
Date
Group
No.
Release
Page
8.2014
511
008
01
1(19)
Brake Drum, Replacement
Steer Axle
CXU, CHU, GU, TD
FSB 511-008, Brake Drum, Replacement (Steer
Axle)
(August 2014)
Some MACK CXU, CHU, GU, and TD trucks built between 08/29/2011 and 06/30/2014,
equipped with a MACK 14.6k steer axle, unitized hub, and 152 mm (6.0 in) wide Meritor brake
shoes can show signs of brake shoe protrusion beyond the brake drum. This condition is
resolved by installing new 152 mm (6.0 in) brake shoes, new dust shields, and new 178 mm
(7.0 in) wide brake drums (20536276).
Note: This bulletin does not apply to MACK Trucks Australia.
W5092666
Required Parts (Brake Drum Replacement)
Item
Description
Part Number
Qty
1
Brake Drum, 178 mm (7.0 in) wide
20536276
2
2
Meritor Brake Shoe Kit, 152 mm (6.0 in) wide
8235–KSMA15014715QP
2
3
Brake Dust Shield, Left, Meritor
22375171
2
4
Brake Dust Shield, Right, Meritor
22375304
2
5
O-Ring, Hub Cap
3197784
2
PV729-FSB511-008_M
USA66270
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
Decommissioning the Truck for Repair
You must read and understand the precautions and guidelines in Service Information,
group 50, "General Safety Practices, Brakes" before performing this procedure. If you are
not properly trained and certified in this procedure, ask your supervisor for training before
you perform it.
NOTE: Information is subject to change without notice. Illustrations are used for reference
only and can differ slightly from the actual vehicle being serviced. However, key
components addressed in this information are represented as accurately as possible.
1 Park the vehicle on a flat and level surface.
2 Apply the parking brake.
3 Place the transmission in neutral or park.
4 Install the wheel chocks.
W7086748
Page
2(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
5 Disconnect the cable from the battery’s negative terminal.
W3086747
Brake Drum, Replacement, Meritor (1.9 hrs)
Note: The left side is shown for instructional purposes.
1 Lift the steer axle with a jack, place the truck on jack stands, and remove the jack.
2 Remove the wheel nuts.
W5092676
Page
3(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
3 Remove the wheel.
W5092677
4 Remove the slack adjuster pawl.
Note: The Meritor slack adjuster is shown in this procedure for backing off the brakes.
However, this procedure is similar for other brands.
W5092669
Page
4(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
5 Back off of the brake (slack adjuster).
W5092670
6 Remove the brake drum.
Note: Discard the brake drum.
W5092678
Page
5(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
7 Remove the brake shoes, brake springs, and rollers.
W5092674
8 Remove the hub cap.
W5092679
Page
6(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
9 Remove the snap ring (1), lock plate (2), hex nut (3), and D-Washer (4).
W5092874
10 Remove the hub.
W5092680
Page
7(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
11 Remove the brake spider and dust shield from the steering knuckle.
Note: Disconnect the brake chamber hose.
W5092681
12 Remove the six fasteners securing the existing dust shields.
W5092682
Page
8(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
13 Remove the dust shield sections and discard.
W5092683
14 Assemble the new dust shield and brake spider.
Note: See the table on page 1 for the correct dust shield part number.
W5092684
Page
9(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
15 install the fasteners securing the new dust shield and brake spider.
16 Tighten the fasteners to 40 ± 5 Nm (29 ± 3 ft-lb).
W5092685
17 Install the brake spider assembly.
Note: Connect the brake chamber hose.
18 Tighten the fasteners to 230 ± 23 Nm (170 ± 17 ft-lb).
W5092686
Page
10(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
19 Check the threads on spindle and the hex nut to ensure they are serviceable.
Note: If the threads are damaged on spindle or hex nut, repair or replace as required.
20 Install the hub assembly and D-washer.
Note: Ensure wheel bearing o-ring is in the correct position and undamaged during hub
installation.
W5092867
Page
11(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
21 Install the hex nut and tighten by hand.
22 Tighten the hex nut to 150 ± 30 Nm (110 ± 22 ft-lb).
23 Rotate the hub 20 revolutions in any direction.
24 Tighten the hex nut again to 1000 ± 100 Nm (737 ± 73 ft-lb)
W5092868
25 Position the lock plate onto the hex nut.
W5092869
Page
12(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
26 Install and secure the snapping ring.
Note: Ensure the snapping ring located securely in the spindle groove.
W5092870
27 Assemble the o-ring (part number 3197784) and hub cap (2).
28 Install the hub cap (2) and o-ring (1) onto the hub.
Note: To prevent damage to the o-ring during hub cap installation, lubricate the o-ring.
Note: Do not lubricate the hub cap threads.
W5092871
Page
13(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
29 Tighten the hub cap to 500 ± 50 Nm (368 ± 37 ft-lb)
30 Install the replacement brake shoes, springs and rollers.
Note: The brake springs and rollers are included in the brake shoe kit.
W5092674
31 Install the replacement brake drum (178 mm (7.0 in) wide). See the table on page 1 for the
correct part number.
W5092678
Page
14(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
32 If applicable, loosen the brake chamber clamp and re-position the clamp at a 45° angle or
until proper clearance of the wheel is obtained. See figure below.
Note: Do not rotate the brake chamber. Rotate the clamp only.
Note: Ensure the brake chamber clamp does not interfere with the wheel.
33 If applicable, tighten the brake chamber clamp fastener to 44 ± 4 Nm (32 ± 3 ft-lb).
W5092675
34 Install the wheel.
W5092677
Page
15(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
35 Install the wheel nuts.
36 Tighten the wheel nuts to 610 Nm (450 ft-lb).
W5092676
37 Adjust the brake as recommended per (slack adjuster) manufacturer.
Note: The Meritor slack adjuster is shown in this procedure for adjusting the brake.
However, this procedure is similar for other brands.
W5092670
Page
16(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
38 Install the slack adjuster pawl.
39 Tighten the slack adjuster pawl to 21 ± 3 Nm (186 ± 30 in-lb).
W5092669
40 Repeat steps 1 through 39 for the right side of the truck.
41 Lift the steer axle with a jack, remove the jack stands, and lower the axle.
42 Go to Commissioning the Truck for Operation.
Page
17(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
Commissioning the Truck for Operation
1 Connect the battery cable to the negative (ground) terminal.
W3086758
2 Remove the wheel chocks.
W7086759
Page
18(19)
Mack Trucks, Inc.
Field Service Bulletin
Date
8.2014
Group
No.
Release
511
008
01
Reimbursement
This repair may be eligible for reimbursement
if a product failure was experienced within
time and mileage limits of the applicable
Warranty coverage. Reimbursement is
obtained via the normal claim handling
process.
UCHP
Reimbursement
eWarranty
Reimbursement
Claim Type (used only when uploading from
the Dealer Bus. Sys.)
01
01
Primary Labor Code (Brake Drum, Replacement)
5112-03-09-07
1.9 hrs.
5126B–01–80
1.9 hrs.
Causal Part
25017906
25017906
Labor Code
MACK Trucks North America reserves the right to make any changes in design or to make
additions to or upon its products without incurring any obligations to install the same on
vehicles previously built.
Page
19(19)