Tadano TR-800XXL4, Service Manual

Page: 303 / 402

38
W232-0032E
T - 5 T - 5
Air Dryer
Symptom Probable cause Remedy
If the purge time is too short, the
desiccant regeneration capability will be
reduced. Inspect the check valve and O-ring.
(Purge time should be approximately 35 seconds
from 890 kPa (129psi) to 0 kPa (0psi).) Condensate
flows out from
the air tank.
If the pressure in the purge chamber is
too low, the desiccant regeneration
capability will be reduced. Check the governor discharge pressure. If it is
different from the specified value, adjust or
replace the governor.
The drain valve is frozen and will not
open. If there is an open circuit in the heater, replace
the heater.
(Check the continuity with a tester.)
• If there is a thermostat failure, replace the
thermostat.
(Leave at 0°C (32°F) or less, then check the
continuity with a tester.)
• Check that no wires have been disconnected.
• If left for a long time in a cold environment, time
will be required for the temperature to rise
after the heater is turned ON.
(Approximately 15 - 20 minutes to rise -20°C -
0°C (-4°F - 32°F.)
If the governor discharge pressure is 490
kPa (71psi) or less, the drain valve will not
open. Check the governor discharge pressure. If it
differs from the specified value, adjust or replace
the governor.
No condensate
is discharged
from the
exhaust port.
A foreign substance (carbonized oil) has
entered during the valve operation,
preventing valve operation. Disassemble and inspect the valve operation
parts. Remove any foreign substances that are
found.
The drain valve is frozen and will not
close. If there is an open circuit in the heater, replace
the heater.
• If there is a thermostat failure, replace the
thermostat.
• Check that no wires have been disconnected.
• If left for a long time in a cold environment, time
will be required for the temperature to rise
after the heater is turned ON.
Air leaks from
the exhaust
port.
A foreign substance has been caught in
the valve, preventing it from sealing. Disassemble and inspect the valve, and remove
any foreign substances. If the valve seal surface
is scratched, replace the valve component or
valve body.