TM 9-2330-388-14
leakage can be detected by applying soapy water around
d.
Repair. No repair is authorized for the parking
the valve stem. No leakage is permitted. If the valve
leaks, or does not operate, replace valve.
brake control valve.
If malfunction or leakage is
indicated, replace the complete valve.
e.
Installation.
(1) Install fittings on valve ports. Use antiseize
Remove button and nut from control valve so that valve
can be inserted into mounting bracket.
(2) Position control valve in mounting bracket.
Install nut on neck of control valve and tighten securely.
(3) Install button on end of valve stem. Aline
hole in button with hole in stem and install roll pin.
(4) Connect air lines to fittings on valve ports
and remove tags.
(5) Remove blocking from semitrailer wheels.
4-50.
Air Lines, Valves, and Fittings
a.
General. The general arrangement of the air
brake system on the semitrailers is shown in fig. x4-57.
Nylon tubing connects the gladhands on front of semi-
trailer to the brake relay valve on rear air reservoir. Clips
fasten the tubing to the underside of the tank and to the
frame members. Grommets are installed to protect the
tubing where it passes through the frame and cross
members.
Hoses and tubing connect the brake
chambers to the reservoirs and relay valve.
b.
Maintenance. Visually inspect for damage to air
lines, loose clips, or missing grommets. Also check the
following:
Figure 4-56. Parking Brake Control Valve Installation.
(1) Brake hoses should he looped in a way that
c.
Removal
prevents the hoses from hanging below the axle.
(1) Block
semitrailer
wheels
to
prevent
(2) Separators on brake hoses should he
movement.
positioned to prevent brake hoses from rubbing against
axles or other brake hoses.
(2) Exhaust air from system by opening drain
valves on bottom of air reservoirs.
(3) Clips should be bent down securely on
tubing.
(3) Tag and disconnect air lines from elbow
and adapter on control valve.
c.
Replacement of Nylon Tubing.
(4) With a small drift and hammer, remove roll
(1) Block
semitrailer
wheels
to
prevent
pin which secures button to stem of control valve.
movement.
Remove button.
(2) Exhaust air from system by opening drain
(5) Remove nut (in neck of valve) and pull the
valves on bottom of air reservoirs.
control valve from the mounting bracket.
(6) Remove fittings from valve ports.
4-119