4-8
BRAKE SYS TEM MAIN TE NANCE
WARN ING
1. WHEN CRAWL
ING UN
DER THE
SEMI TRAILER IS NEC ES SARY, CHOCK
ALL WHEELS OF THE TRAILER AND
TRAC TOR. WHEN JACK ING IS NEC ES -
SARY, CHOCK ALL WHEELS AND
SUP PORT THE SEMI TRAILER UN DER -
CAR RIAGE WITH JACK STANDS SUF -
FI CIENT TO WITH STAND THE WEIGHT
OF THE SEMI
TRAILER AND LOAD.
F A I L
U R E T O T A K E A D E
Q U A T E
SAFETY MEAS URES MAY RE SULT IN
SE RI OUS PER SONAL IN JURY OR
DEATH.
2. USE GREAT CARE IF WHEELS OR
BRAKE DRUMS MUST BE HAN
DLED.
THEY MAY BE VERY HOT AND CAN
CAUSE SE RI OUS BURNS.
4-8.1
Gen eral
.
A daily gen eral in spec tion will re veal the most
com
mon prob
lems found in the spring brake sys
-
tem. This in spec tion should in clude the fol low ing:
a.
Check air hoses for chaf ing, bends, kinks,
or dam aged fit tings. Re place de fec tive hoses.
b.
Check the brake sys tem for loose, miss ing,
de formed, or cor roded fas ten ers. Re place
and tighten de fec tive hard ware.
c.
Check brake lin ings for ex
ces
sive wear or
dis tor tion.
d.
Drain air res er voir daily. A drain cock on the
bot tom of each air res er voir vents the tank to
drain col lected wa ter and oil. If held open, air
pres sure in the tanks is re lieved, caus ing the
emer
gency or park
ing brakes to be ap
plied
(See Fig ure 4-8).
4-8.2
Spring Air Brake Cham bers (30/30)
Check for faulty units. Check the con den sa tion
holes on the un
der
side of the brake cham
bers to
make sure they are open. The spring brake has
two brake cham
bers, a serv
ice cham
ber and an
emer
gency cham
ber or spring cham
ber. Serv
ice
brake cham
bers should be dis
as
sem
bled and
cleaned at 50,000 miles or yearly. The dia phragm
and any mar ginal parts should be re placed. When
re plac ing the serv ice dia phragm, re place the cor re -
spond ing parts for the other cham ber on the same
axle (to aid in even brake ap pli ca tion and re lease).
Ex am ine yoke pin for wear and re place as nec es -
sary. The spring cham ber should not be serv iced.
Re place en tire unit (both serv ice and spring cham -
ber) if spring cham ber be comes faulty.
WARN ING
THE SPRING BRAKE CHAM
BER EM
-
P L O Y S A S P R I N G W I T H H I G H
FORCES. SERV
ICE SHOULD NOT BE
AT TEMPTED. SE RI OUS IN JURY OR
DEATH MAY RE SULT.
4-15
FIG URE 4-8 DRAIN COCK LO CA TIONS
Summary of Contents for 318C
Page 3: ...MODELS 318C BOEING TRAILER OPERATOR S MANUAL PURCHASED FROM DATE ADDRESS PHONE NO SERIAL NO i...
Page 8: ......
Page 12: ......
Page 32: ...3 20 FIGURE 3 6 STEPS FOR LOADING AND UNLOADING...
Page 36: ...3 24 FIGURE 3 8 REAR IMPACT GUARD AND ANTILOCK BRAKE SYSTEM...
Page 52: ...4 14 FIGURE 4 6 CHECKING AXLE ALIGNMENT FIGURE 4 7 EXAMPLES OF CAMBER...
Page 56: ...4 18 FIGURE 4 10 AXLE AND BRAKE ASSEMBLY...
Page 64: ...4 26 FIGURE 4 16 MOUNTING TIRES AND WHEELS FIGURE 4 17 STUD TIGHTENING SEQUENCE...
Page 76: ...5 10 NOTES...
