Diesel Exhaust Fluid (Def) Tank; Cleaning And Flushing The Tank - JLG 1850SJ Service And Maintenance Manual

3.20 DIESEL EXHAUST FLUID (DEF) TANK

Refer to Figure 3-44. and Figure 3-45.
Diesel exhaust fluid (DEF) is a urea solution consisting of 32.5%
urea and 67.5% deionized water. DEF is used in selective cata-
lytic reduction (SCR) to lower nitrogen oxide (NOx) concentra-
tion in exhaust emissions.
DEF is temperature sensitive in storage. If stored between 75°F
(24°C) and 12°F (-10°C), it can be stored for 2 years. In the
machine's DEF tank, the storage life is 4 months. After 4
months, the DEF must be drained from the tank, properly dis-
posed of, and the tank cleaned and flushed. If the machine has
been idle in an extreme cold environment (-40° to 32°F [-40° to
0°C]), the interval is reduced to 2 months.
NOTE: DEF freezes at 12°F (-11°C).
3121619
SECTION 3 - CHASSIS & TURNTABLE

Cleaning and Flushing the Tank

If contaminated fluid or foreign material is found in the tank,
the tank must be cleaned. Use the following procedure for
cleaning.
1. Remove the DEF tank drain plug, and drain any fluid into
a suitable container. Dispose of fluid properly.
2. Clean the header with a mixture of warm water and a
light petroleum based soap.
3. Clean DEF tank with a high pressure washer, or flush
tank with hot water for five minutes and drain water.
4. If DEF fluid lines are contaminated, tag and remove the
lines from the DEF pump module and flush with a mix-
ture of warm water and a light petroleum based soap.
5. Refill DEF tank with water until it overflows. Completely
flush tank with water.
6. Empty DEF tank, and dispose of contaminated water
properly.
7. Rinse the tank and all soap residue with deionized or
distilled water and allow to air dry.
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