TM-5-2330-378-14-P
SEMITRAILER, LOWBED: 40 TON CONSTRUCTION EQUIPMENT TRANSPORTER M870 AND M870A1
TECHNICAL MANUAL; OPERATOR'S, UNIT, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST)
JUNE 1999
TM-5-2330-378-14-P - Page 216 of 524
TM5-2330-378-14&P
4-59.
EMERGENCY RELAY VALVE REPLACEMENT, OPERATING TEST, AND LEAKAGE
TEST (M870AI) (continued).
c.
OPERATING
TEST
1
With gladhands
connected
to towing vehicle, apply brakes.
Check to see that brakes of all semitrailer
wheels
apply properly.
2.
Release brakes.
Check to see that each brake releases properly.
3.
With brake system fully pressurized,
close shutoff cock on emergency
hose in towing vehicle.
Disconnect
gladhands
tagged EMERGENCY
from towing vehicle.
Make sure semitrailer brakes apply automatically.
4.
Connect gladhands tagged EMERGENCY to towing vehicle. Open shutoff valve cock in towing vehicle.
Check to see that brakes release automatically.
d.
LEAKAGE TEST
1 .
With air system connected,
apply a solution of detergent (Item 4, Appendix F) and water to flanges holding
diaphragm
in spring brake chamber, and to gladhands tagged SERVICE.
No leakage is permitted.
Tighten nuts
on flanges and coupling on gladhands
as required.
2.
With brake system fully pressurized,
close shutoff cock on emergency
line intowing vehicle.
Disconnect glad-
hands tagged EMERGENCY
from towing vehicle.
Make sure semitrailer brakes apply automatically.
Coat
emergency
relay valve exhaust port with a solution of detergent (Item 4, Appendix F) and water.
3.
Leakage must not exceed a one-inch (2.5 cm) bubble in three seconds.
If excess leakage is found, replace
emergency
relayvalve (subparas 4-59a and 4-59b).
FOLLOW-ON TASKS:
- None
4-128
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