MAINTENANCE/SERVICE
Cab
Air
System
COMPRESSOR PROTECTION
The compressor is protected from excessively
low suction
and
high
discharge pressures
by
tINa
switche
s:
To
pr
eve
nt
damage
to
th
e compressor, if the air
conditioning
system
is
shut
down
by
either
switch, locate the
so
urce
of
the problem and
cor
rect it before operati
ng
the system.
Low suction pre
ss
ure switch
is
located at the
outlet of the evaporator
(u
nder seat
in
cab
).
It
will
close
when
the pressure drops below
4±2
psi
and
re
-open when pressure rises above
20±5
psi.
REFRIGERANT OIL
Whenever the machine
is
first started after
sto
ra
ge
for more than
one
week: Turn blower
switch
to
"O
FF
" and turn
Ale
temperature contr
ol
swi
tch
to
maximum cooli
ng
. Start engine
and
operate at low
idl
e.
Click blower switch from
"OFF" to "LOW' for one second, then back
to
"O
FF
" for 5 to
10
seco
nd
s. Repeat this cycle ten
times to dist
ri
bute the
oil
throughout the system.
High
di
scharge pressure switch is located on
the
re
ceiver drier (rear of tractor,
behind
right
side panel). It will close if pressure exceeds
325±
10
psi
and
re·open
when
pre
ss
ur
e drops
below
250±30 p
si.
LOW SIDE
HIGH
SIDE
POSSIBLE
PRESSURE
PRESSURE
CAUSE
VERY LOW
V
ER
Y L
OW
L
ack
of R
134a
L
OW
LOW
loss
of R 1
34a
Restriction
be
tw
een
co
ndense
r a
nd
dri
er
LOW
LOW
OR
Resltiction
between
d
rier
and
exp
an
sion
valve
N
ORMAL
Expans
io
n
va
lve
plugg
ed
Expans
io
n
valve
stuck
closed
Inoperative
b
lo
w
er
mo
t
or
Plugged
fiRer
or
ev
aporator
core
Moistu
re
in
sys
t
em
Defective
temperature
control
sw
itch
Restriction
at
expansio
n
valve
Restriction
In
evapo
ra
to
r
Restrict
io
n
between
evaporator
and
compressor
suction
HI
GH
L
OW
Compressor
belt
s
lipp
ing
Magnet
ic
cl
utch
s
lipping
Com
pr
esso
r i
nt
emal
fa
il
ure
HIGH
HI
GH
Co
nd
enser
malfunction
Co
nd
en
se
r coli p
lugged
Exparlsion
valve
stuck
open
Restriction
between
co
mpres
scr
and
con
de
nse
r
Restriction i
ns
ide
condenser
Overcharge
of
refrigera
nt
A
ir
in system
HIGH NORMAl
Expans
io
n
valve
st
uck
open
NORMAL
H
IG
H
Rest
riction
between
compressor
and
condenser
Restriction
i
nside
con
d
enser
Overcharge
of
refr
ig
erant
LOW
HIGH
Re
striction
be
tw
een
co
mp
ressor
and
condenser
Re
strict
ion
Inside
condense
r
NOTE: Service ports a
re
located
on
suction and
di
S
Cha
rge
hoses at compressor.
110
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