Hino 600, Руководство по ремонту, Страница: 317 / 451

SERVICE BRAKE (FULL AIR BRAKE) BR02–39
INSPECTION AND REPAIR
EN0680202H200005
1. PREVENTIVE MAINTENANCE
(1) Every 3 months; 25,000 miles; or 900 operating hours; or during the
vehicle chassis lubrication interval, make the visual inspections noted
in "SERVICE CHECKS."
(2) Every 12 months; 100,000 miles; or 3,600 operating hours, perform
"OPERATIONAL AND LEAKAGE TESTS."
2. SERVICE CHECKS
(1) Remove any accumulated contaminants. Visually inspect the valve's
exterior for excessive wear or physical damage. Repair/replace as
necessary.
(2) Inspect all air lines connected to the valve for signs of wear or physical
damage. Repair/replace as necessary.
(3) Test air line fittings for excessive leakage. Repair/replace as neces-
sary.
3. LEAKAGE AND OPERATIONAL TESTS
To perform the following tests, connect two separate 120 psi air
sources to the PP-DC supply ports. Tee an accurate test gauge into
the supply lines, and provide for a means to control supply line pres-
sure. Connect a small volume with a gauge to the delivery port.
(1) Leakage test
a.
Supply the valve with 120 psi from the primary reservoir supply
port. With the button out, coat the exhaust port and the plunger
stem with a soap solution. Leakage should not exceed a 1" bubble
in 5 seconds. There should be no leakage from the secondary
reservoir supply port.
b. With the button out, supply the valve with 120 psi from the sec-
ondary reservoir supply port. There should be no leakage from
the primary reservoir supply port.
c. With the button in, coat the exhaust port and the plunger stem
with a soap solution. Leakage at both areas should not exceed a
1" bubble in 3 seconds.
(2) Operational test
a.
With the button out, supply either supply port with 120 psi of air.
Then push the button in. Air pressure should rise in the delivery
volume equivalent to supply pressure.
b. Pull the button out. Delivery pressure should exhaust to 0 psi.
c. Build each supply source to 120 psi. Decrease supply pressure at
the secondary service reservoir supply port at a rate of 10 psi per
second. Primary supply pressure and delivery pressure should
not drop below 100 psi.
Repeat the test for decreasing primary service reservoir pressure.
d. Build each supply source to 120 psi. Then decrease both supply
pressures to below 20 to 30 psi. The button should automatically
"pop" out when pressure drops within that range.
4. REMOVAL
(1) Identify and mark or label all air lines and their connections on the
valve.
(2) Remove the PP-DC from the vehicle and save the mounting hard-
ware.