TM 5-3800-205-23-1
TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0005 00
AIR LEAKAGE CHECKS - CONTINUED
d.
Check for leakage at service brake control valve.
NOTE
If air pressure drops below cut-out pressure of 125 psi (860 kPa), start and run engine until air pressure
reaches cut-out pressure. Once pressure is reached, stop engine.
e.
Check for leakage at hoses, lines, and connections between service brake control valve and between air tanks and
relay valves.
f.
Check for leakage at valves and pressure switches.
g.
Check for leakage at hoses, lines, and connections between service brake control valve and parking/emergency
brake control valves.
h.
Release parking brake (TM 5-3800-205-10-1 or TM 5-3800-205-10-2).
NOTE
When checking air valves for leakage, check exhaust passages for restrictions such as mud or dirt. A restric-
tion in an exhaust passage will prevent release of pressurized air during normal operations.
i.
Check for leakage at hoses, lines, and connections between parking brake control valve and double check valves.
j.
Check for leakage at double check valves.
k.
Push and hold service brake pedal. Check for leakage at hoses, lines, and connections between service brake con-
trol valve and scraper/water tank brake actuators.
l.
Continue holding service brake pedal and check for leakage at hoses, lines, and connections between service brake
control valve and tractor brake actuators.
m.
Release service brake pedal.
PARKING AND EMERGENCY BRAKE CONTROL VALVES TEST
1.
Tools and Special Tools.
a.
Tool kit, general mechanic's (Item 33, WP 0172 00).
b.
Tool outfit, hydraulic systems (HSTRU) (Item 35, WP 0172 00).
2.
Parking and Emergency Brake Control Valves Test.
a.
Start engine (TM 5-3800-205-10-1 or TM 5-3800-205-10-2) and allow air pressure to reach cut-out pressure of
125 psi (860 kPa).
b.
Release parking and emergency brakes (TM 5-3800-205-10-1 or TM 5-3800-205-10-2).
c.
Push brake pedal rapidly several times until control knobs automatically move to ON position.
d.
Install air pressure gage in accordance with Air System Pressure Test in this work package.
e.
Observe pressure indication on test gage.
f.
Correct pressure that will automatically engage brakes is 40 psi (280 kPa). If pressure on gage is not correct, oper-
ation of control valve is not correct. Replace control valve (WP 0089 00).
0005 00-15
