NMC-WOLLARD 140 - Rear Drum Brake Assembly and Installation

Do not allow linings to drag on drum or they will heat up and lock. The
linings will be charred and rendered useless, resulting in brake failure.
4. Adjust the linings until a slight resistance can be felt when the brake drum is
rotated. Then adjust in the other direction until the drum can just rotate freely.
1.5.4 Rear Drum Brake Assembly and Installation
See parts illustration in Chapter 4.
1. Before assembly, apply a thin layer of brake lubricant (or No. 2 grease) to the
following parts:
a. Ends of cylinder push rods (item 21).
b. Adjusting bolt (item 14) threads and on ends (item 13 and 15) where they
contact shoes.
c. All shoe sliding surfaces.
d. Anchor pins (item 8), anchor pin holes, and anchor pin slots.
2. Position wheel cylinder, install and lock washers, and tighten to 15-20 ft-lbs
torque.
3. Install the two anchor pins in the holes in the backing plate.
4. Put the trailing shoe in position into the anchor pin slot and engage it with the wheel
cylinder push rod.
5. Install the two trailing shoe hold-down pins through the backing plate.
6. To install the two hold-down clips, engage the clip on the pin and rotate the clip
down until it sets flat on the shoe.
7. Install the stamped adjusting spring lever (item 16) on the leading shoe.
8. Position leading shoe in anchor pin slot and position adjusting bolt assembly (items
13, 14, & 15) between shoes. At the same time, install the lower spring.
9. Hold the leading shoe in correct position and install the hold-down pin and clip.
10. Install the two upper springs. Place the green spring on the leading shoe for the
right-hand brake and on the trailing shoe for the left-hand brake.
11. Install the short automatic adjustment wire (item 19) to connect the pivot to the pin
near the anchor location.
12. Install the long automatic adjustment wire (item 17) to connect the pivot (item 18) to
the stamped automatic adjustment spring.
13. Install the automatic adjustment pivot and spacer to the leading shoe on its
shoulder bolt fastener. Be careful that the pivot is not pinched under the edge of the
shoulder.
AUGUST 31, 2008 CHAPTER 3 OVERHAUL
PAGE 8 1 GENERAL REPAIR
M140 Tow Tractor Manual No. 46054