ACURA NSX 1997 Service Repair Manual

Heater-Evaporator Uni t
Replacemen t
SRS component s ar e locate d in thi s area . Revie w th e SR S
componen t locations , precautions , an d procedure s i n th e
SR S sectio n 24 befor e performin g repair s o r service .
1 . Remov e th e blowe r uni t (se e pag e 22-67 ).
2 . Whe n th e engin e i s cool , drai n th e engin e coolan t
fro m th e radiato r (se e sectio n 10 ).
D o no t remov e th e radiato r ca p whe n
th e engin e i s hot ; th e engin e coolan t i s unde r
pressur e an d coul d severel y scal d you .
CAUTION : Engin e coolan t wil l damag e paint . Quick -
l y rins e an y spille d engin e coolan t of f painte d sur -
faces .
3. Disconnec t th e heater valve cabl e fro m th e heate r
valve .
4 . Disconnec t th e heater hoses. Engin e coolan t wil l
ru n ou t whe n th e hose s ar e disconnected , drai n i t
int o a clea n dri p pan .
HEATE RVALVE CABL E
HEATE R VALV E
5. Recove r th e refrigeran t fro m th e A/ C syste m wit h a
R-134 a refrigeran t Recovery/Recycling/Chargin g
System . (se e pag e 22-73 ).
6 . Disconnec t th e receive r lin e an d th e suctio n lin e fro m
the evaporator . Ca p th e ope n fitting s immediatel y
to kee p moistur e ou t o f th e system .
RECEIVE R LIN E
SECTION LIN E
7. Remov e th e dashboar d (se e sectio n 20 ).
8 . Remov e th e heate r duct .
9 . Remov e th e fou r mountin g bolts , disconnec t th e con -
nector s fro m th e contro l unit s an d th e evaporato r
temperatur e senso r connecto r fro m th e contro l uni t
bracket , the n remov e th e contro l uni t bracket .
CORROSIO N RESISTAN T
B°L T EVAPORATORTEMPERATUR E
SENSO R CONNECTO R
CONTROLUNITBRACKE T
6 x 1. 0 m m9.8 N- m(1.0 kgf-m ,
7. 2 Ibf-ft) '
SRS MAI NHARNES S
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
10. Remov e th e woofe r enclosur e (se e sectio n 23 ).
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11. Disconnec t th e connector s fro m al l th e contro l
motors an d sensor s attache d t o th e heater -
evaporato r unit .
1 2 . Remov e th e tw o mountin g bolt s an d tw o nuts , the n
remov e th e heater-evaporato r uni t throug h th e
passenge r door .
CORROSIO N RESISTAN TBOLTHEATER-EVAPORATO R UNIT
NUT S29 N- m (3. 0 kgf-m ,
2 2 Ibf-ft )
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
13. Instal l th e heater-evaporato r uni t i n th e revers e
orde r of removal , and :
• I f you'r e installin g a ne w evaporator , ad d
refrigeran t oi l (ND-OI L 8 ) se e pag e 22-69 ).
• Replac e O-ring s wit h ne w one s a t eac h fitting ,
and appl y refrigeran t oi l t o them .
NOTE : B e sur e t o us e th e righ t O-ring s fo r
R-134 a t o avoi d leakage .
14. Fil l th e radiato r an d reservoi r tan k wit h th e prope r
engine coolan t mixture . Blee d th e ai r fro m th e cool -
in g syste m (se e sectio n 10 ).
CAUTION : Follo w th e sequenc e describe d in th e ai r
blee d procedure . I f you don't , yo u ma y leav e ai r i n
th e syste m whic h coul d damag e th e engine .
15. I f necessary , adjus t th e heate r valv e cable :
• Se t th e ai r mi x contro l moto r a t COO L positio n
(se e pag e 22-57 ).
• Connec t th e en d o f th e heate r valv e cabl e t o th e
heate r valv e arm .
• Gentl y slid e th e cabl e oute r housin g bac k fro m
the en d enoug h to tak e u p an y slac k in th e cable ,
but no t enoug h t o mak e th e othe r en d mov e th e
ar m o n th e ai r mi x contro l motor . The n sna p th e
clam p dow n ove r th e cabl e housing .
CLAMP
HEATE R VALV EARM
HEATE R VALV ECABLE
16. Tur n th e blowe r on , an d mak e sur e tha t ther e is n o
air leakage .
1 7 . Charg e th e syste m (se e pag e 22-91 ), an d tes t per -
formanc e (se e pag e 22-70 ).
SR S UNI T
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Heater-Evaporator Unit

Overhaul

1. Remove the heater core cover, remove the pipe clamp, then pull out the heater core.

2. Remove the lower half of the housing, then remove the evaporator.

3. Remove the expansion valve if necessary.

HEATER CORE

PIPE CLAMP

AIR MIX DOOR

LOWER HALF

OF THE HOUSING
CAPILLARY TUBE

SUCTION LINE

EVAPORATOR

The expansion valve capillary tube

must be touching the suction line.

4. Assemble the heater-evaporator unit in the reverse order of disassembly. Hold the expansion valve capillary tube

down against the suction line, and wrap it with tape to hold it there.
EXPANSION VALVE
HEATER CORE

COVER

TAPE

Replace

O-RINGS

Replace

SUCTION LINEProCarManuals.com

"DEF" Door Adjustment

Connect the control rod to

the clip.
Turn this lever all the way

clockwise and hold it there.

Turn this lever clockwise

and hold it against its stop.
"HEAT" Door Adjustment

Reposition gear 2 so this

mark lines up with the mark

on gear 1.
Loosen this screw in gear 2.

GEAR 1
GEAR 2ProCarManuals.com

Condenser

Description

Dual condensers are mounted behind the right and left side of the front bumper as shown. The cooling efficiency of parallel-

dual condensers is as good as or better than a single condenser mounted in front of radiator.

LEFT CONDENSER

RECEIVER/DRYER

RIGHT CONDENSORProCarManuals.com

Replacement
1. Disconnec t th e negativ e cabl e fro m th e battery .
2 . Remov e th e fron t bumpe r (se e sectio n 20 ).
3 . Recove r th e refrigeran t usin g a R-134 a refrigeran t
Recover/Recycling/Chargin g Syste m (se e pag e
22-73 ).
4 . Disconnec t th e discharg e lin e C an d th e condense r
line s fro m th e condenser . Ca p th e ope n fitting s
immediatel y t o kee p moistur e an d dir t ou t o f th e
system .
(Right Condenser )
(Left Condenser )
CONDENSER
LIN E C
CONDENSE R
LIN E A
CONDENSE RLINE A
DISCHARG ELINEC
5. Disconnec t th e connecto r fro m th e condense r fan ,
remov e th e tw o mountin g bolt s an d nut , the n
remov e th e condenser .
CORROSIO N RESISTAN T BOL T
(Righ t Condenser )
RIGHT CONDENSE R
MOUNTING BOLT S6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
(Left Condenser )CONNECTORNUT
LEF T CONDENSE R
MOUNTING BOLT S6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
6. Instal l th e condense r i n th e revers e orde r o f
removal ; and :
• I f you'r e installin g a ne w condenser , ad d
refrigeran t oi l (ND-OI L 8 ) (se e pag e 22-69 ).
• Replac e O-ring s wit h ne w one s a t eac h fitting ,
an d appl y refrigeran t oi l t o them .
NOTE : B e sur e t o us e th e righ t O-ring s fo r
R-134 a t o avoi d leakage .
• Charg e th e syste m (se e pag e 22-91 ), an d tes t it s
performanc e (se e pag e 22-70 ).
NU TCONNECTO R
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Condenser

Overhaul

1. Remove the four bolts and nuts. Then separate the condenser duct from the condenser shroud, and remove the

condenser.

2. Remove the three mounting screws, then remove the condenser fan from the condenser shroud.

CONDENSER

CONDENSER

DUCT

NUTS

6 x 1.0 mm

9.8 N-m (1.0 kgf-m, 7.2 Ibf-ft)

CONDENSER FAN
SCREW

CONDENSER

SHROUD

SPACER

3. Assemble the condenser in the reverse order of disassembly. Be careful not to damage the tabs on the condenser

shroud when you attach it to the air intake duct.ProCarManuals.com

Compressor
Description
This compresso r i s a DENS O pisto n typ e fo r R-134a . A revolvin g incline d dis c drive s th e surroundin g 1 0 reciprocatin g pis -
tons . A s th e incline d dis c revolved , i t pushe s th e pistons , protecte d b y a cerami c shoe , thu s compressin g th e refrigerant .
RELIEF VALVE
PISTON S
FIEL D COI L
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Compressor
Illustrated Inde x
RELIE F VALV E
Replacement , pag e 22-8 7
2 5 N- m (2. 6 kgf-m , 1 9 Ibf-ft ) CENTE
R BOL T
PRESSUR E PLAT EInspection , pag e 22-8 5
SHIM(S )
SNA P RIN G B
Replace .
PULLEYInspection , pag e 22-8 5
SNA P RIN G A
Replace .
FIELD COI LInspection , pag e 22-8 5
O-RIN G
Replace .
SUCTIO N SERVIC E VALV E
COMPRESSO R(Do no t disassembly )
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Replacement
1. I f th e compresso r stil l works , ru n th e engin e a t idl e
for a fe w minute s wit h th e A/ C on , the n shu t th e
engin e of f an d disconnec t th e negativ e cabl e fro m
the battery .
2. Recove r th e refrigeran t usin g a R-134 a refrigeran t
Recovery/Recycling/Chargin g System . (se e pag e
22-73 ).
3 . Disconnec t th e compresso r connector .
COMPRESSO R
CONNECTO R
4. Rais e th e vehicl e o n a hoist . Mak e sur e it' s properl y
supporte d (se e sectio n 1 ).
5 . Remov e th e fron t bea m (se e sectio n 5 ).
6 . Disconnec t th e suctio n an d discharg e hose s fro m th e
compressor . Ca p th e ope n fitting s immediatel y t o
kee p moistur e an d dir t ou t o f th e system .
DISCHARG E HOS E
SUCTIO N
HOS E
8 x 1.2 5 mm29 N- m(3.0 kgf-m ,
2 2 Ibf-ft )
7. Loose n th e idle r pulle y cente r nu t an d adjustin g bolt ,
the n remov e th e bel t fro m compressor .
ADJUSTING BOL T
IDLE R PULLE Y CENTE R
NUT44 N- m (4. 5 kgf-m ,
3 3 Ibf-ft )
8. Remov e th e fou r mountin g bolt s an d compressor .
COMPRESSO R
MOUNTING BOLT S8 x 1.2 5 mm22 N- m (2. 2 kgf-m ,
1 6 Ibf-ft )
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