8
Rosco Maximizer 3B Asphalt Distributor
8-3
Troubleshooting
Table 8-2. Asphalt Application
SYMPTOM
CAUSE
REMEDY
Asphalt application is
inconsistent
Relief valve on asphalt pump stuck
in open position
Reset relief valve; should be set at 70 psi
Relief valve not seating properly
Take unit to an authorized dealer to check the
seal between the seat and the poppet
Inconsistent temperature and
viscosity between asphalt loads
Monitor asphalt temperature and reheat when
needed. Circulate spraybar for several minutes
before spraying.
Asphalt pump speed too high for
type of nozzles used; relief valve on
pump limits pressure to spraybar;
excess flow bypasses to inlet of
pump.
Decrease truck speed. Refer to calibration
and application rate information to determine
correct settings, (see
2-Way and 3-Way control valves
not fully open
With asphalt tank empty and truck engine OFF,
remove flanged hose ends from 2-Way and
3-Way valves.
With ignition ON, power ON and air pressure
available, set Mode Selection to SPRAY mode.
Check port alignment. There are two socket
head adjusting screws on the vane air actuator
which adjust amount of rotation. Loosen jam
nut and turn set screw in or out to obtain proper
port alignment. Only the set screw in contact
with vane in air actuator should be adjusted.
Asphalt streaks during
spraying.
Incorrect spraybar height
Adjust spraybar high enough so spray fans
completely overlap
Asphalt not heated to
recommended temperature for
spraying
Heat material to temperature recommended by
asphalt supplier
Spraybar nozzles not uniformly set
at 20 degree angle
Check angle setting of all nozzles with Nozzle
Alignment Wrench
Valves not aligned correctly
Check angle setting with Valve Alignment
Wrench
Wrong size nozzle
Refer to Valves and Nozzles in Section 3,
Material & Operation
Asphalt pump speed too slow for
spraybar width or size of nozzles
Refer to calibration and application rate
information at Operating Screens in Section 3,
Material & Operation
Streaking during start of a "shot"
indicates material in spraybar has
cooled
Run distributor in Spray/Bar Circulate mode for
several minutes before starting to spray
Spraybar pressure too low
Increase ground speed
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