b. Cleaning and Inspection.
c. Installation. Install pressure regulating valve as
(1) Clean all parts and dry thoroughly.
illustrated in figure 4-123. Adjust the pressure regulating
(2) Inspect for cracks or other defects. Replace
valve to apply 6 psig in hydraulic tank as indicated on
defective relay valves.
pressure gage in figures 4-119 or 4-120.
c. Installation. Install relay valves as illustrated in
4-137. Trailer Brake Control Valve
a. Removal.
4-135. Emergency-Park Brake Control Valve
a. Removal
(1) Relieve system pressure.
(2) Remove trailer brake control valve as
(1) Relieve system pressure.
illustrated in figure 4-124.
(2) Remove emergency-park brake control valve
as illustrated in figure 4-119 or 4-120.
b. Cleaning and Inspection.
(1) Clean valve and dry thoroughly.
(2) Inspect for cracks or other defects. Replace
defective control valve.
c. Installation. Install control valve as illustrated in
figures 4-119 or 4-120.
4-136. Pressure Regulating Valve
a. Removal.
(1) Relieve pressure from both sides of
regulating valve.
(2) Remove pressure regulating valve as
illustrated in figure 4-123.
Figure 4-124. Trailer brake control valve, removal and
installation
b. Cleaning and Inspection.
(1) Clean valve exterior.
(2) Inspect valve for cracks or other damage.
Replace a defective valve.
c. Installation. Install valve as illustrated in figure 4-
124.
4-138. Tractor Protection Valve
a. Removal.
(1) Drain system pressure.
(2) Remove safety valve as instructed in figures
4-119 or 4-120.
Figure 4-123. Pressure regulating valve, removal and
b. Cleaning and Inspection.
installation.
(1) Clean valve and dry thoroughly.
b. Cleaning and Inspection.
(2) Inspect valve for cracks or other damage.
(1) Clean all parts and dry thoroughly.
Replace a defective valve.
(2) Inspect for cracks, damaged threads, or
c. Installations. Install valve as illustrated in figures
other
defects.
Replace
defective
parts.
4-119 or 4-120.
4-127
