TM 9-2330-392-14&P
4-28A
HYDRAULIC BRAKE ACTUATOR ASSEMBLY REPAIR (Con't).
7.
Remove two locknuts (17), two washers (18), and two capscrews (23) securing hydraulic actuator assem-
bly (8) to trailer. Discard locknuts. Note that two spacers (24) remain with trailer tongue.
8.
Remove hydraulic actuator assembly (8) from trailer tongue.
9.
Remove two spacers (24) from trailer tongue.
10. Remove four capecrews (21) securing master cylinder mounting plate (26) to brake actuator housing (8).
Remove master cylinder (5) with attached mounting plate (26) from actuator housing (8). Discard cap-
screws (21).
11. Remove hydraulic actuator breakaway lever (33) and attached breakaway cable (32) from actuator hous-
ing (8). Then remove breakaway leaf spring (34).
12. Remove two capscrews (27), nuts (30), washers (29), and springs (28) securing master cylinder mounting
plate (26) and push rod assembly (31) to master cylinder (5). Carefully remove push rod assembly (31)
and mounting plate (26) from master cylinder (5).
13. Remove nut (20) and washer (25) securing front roller bolt (22) and roller bolt cover (19) to actuator hous-
ing (8). Remove front roller bolt (22), front roller (36), and roller bolt cover (19) from actuator housing
(8).
b. CLEANING AND INSPECTION
Dry cleaning solvent, P-D-680, is toxic and flammable. Always wear goggles and gloves
and use solvent only in a well-ventilated area. Avoid contact with shin, eyes, and clothes,
and DO NOT breathe vapors. DO NOT use near open flame or excessive heat. The sol-
vent’s flash point is 100°F to 138°F (38°C to 59°C). If you become dizzy while using
cleaning solvent, immediately get fresh air and medical help. If solvent contacts eyes,
immediately wash your eyes and get medical aid.
1.
Clean all removed components except master cylinder with dry cleaning solvent and allow to dry.
2.
Inspect components for wear, cracks, breaks, corrosion, or other damage. Replace if damaged.
3.
Inspect master cylinder and damper for leakage. Replace if defective.
4.
Remove any corrosion with a wire brush.
5.
Inspect Teflon bearings (35) in actuator housing (8). Replace if damaged.
c. ASSEMBLY
1.
Install front roller bolt (22), front roller (36), and roller bolt cover (19) into actuator housing (8) and secure
with washer (25) and nut (20).
2.
Carefully install push rod assembly (31) and mounting plate (26) onto master cylinder (5). Install two
capscrews (27), nuts (30), washers (29), and springs (28) to secure master cylinder mounting plate (26)
and push rod assembly (31) to master cylinder (5).
When installing breakaway lever spring (35) onto breakaway lever (34) and actuator
housing (8), you must hold the spring in place until master cylinder (5) is installed. If the
spring is not physically held in place as defined, it can fall out of the actuator housing,
resulting in no surge brake protection for the trailer.
3.
Install breakaway leaf spring (34) and breakaway lever (33) with attached breakaway cable (32) into
actuator housing (8).
4-70.4
Change 1
