1991 ACURA NSX brake

Illustrated Index

The accumulator contains high-pressure nitrogen gas; do not puncture, expose to flame or attempt to
disassemble the accumulator or it may explode; severe personal injury may result.

HYDRAULIC SYSTEM
Relieving Accumulator/line pressure, page 19-62 ('91-'92) ('93-'96)

MASTER CYLINDER
Index/Torque, page 19-12

Inspection, page 19-13

ABS CONTROL UNIT Replacement, page 19-70

BRAKE BOOSTER

Tests, page 19-14 Pushrod clearance adjustment, page 19-15

UNDER-HOOD

RELAY BOX B

UNDER-HOOD
FUSE/RELAY BOX

REAR WHEEL SENSOR

Inspection, page 19-71

Replacement, page 19-72
POWER UNIT
Torque/Inspection, page 19-66
ACCUMULATOR/PRESSURE SWITCHIndex/Torque, page 19-67 FRONT WHEEL SENSOR
Inspection, page 19-71
Replacement, page 19-72
MODULATOR/SOLENOID UNIT

Index/Torque, page 19-63 ('91-'92) ('93-'96)
Solenoid Leak Test, page 19-64 ('91-'92) ('93-'96)
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Pedal Heigh t
Adjustmen t
1. Loose n th e brak e switc h locknut , an d bac k of f th e
brak e switc h unti l i t i s n o longe r touchin g th e brak e
pedal .
2 . Loose n th e pushro d locknut , an d scre w th e pushro d
in o r ou t wit h plier s unti l th e standar d peda l heigh t
from th e floo r i s 21 8 m m (8. 6 in) . Afte r adjust -
ment, tighte n th e locknu t firmly .
3. Scre w in th e brak e switc h unti l it s plunge r i s full y
depresse d (threade d en d touchin g th e pa d o n th e
peda l arm) . The n bac k of f th e switc h 1/ 2 turn , an d
tighte n th e locknu t firmly .
CAUTION : Chec k tha t th e brak e light s g o of f
whe n th e peda l i s released .
NOTE : D o no t adjus t th e peda l heigh t wit h th e
pushro d depressed .
Parking Brak e
Adjustmen t
1. Remov e th e consol e mat , th e fou r screw s an d th e
consol e box .
NOTE : Afte r rea r brak e calipe r servicing , loose n
th e parkin g brak e adjustin g nut , star t th e engine ,
an d depres s th e brak e peda l severa l time s t o se t
the self-adjustin g brake s befor e adjustin g th e brak e
pedal .
Block th e fron t wheel s befor e jackin g
u p eac h sid e o f th e car .
2 . Rais e th e rea r wheel s of f th e ground .
3 . Mak e sur e th e leve r o f th e rea r brak e calipe r con -
tact s th e brak e calipe r pin .
4 . Pul l th e parkin g brak e leve r u p on e notch .
5 . Tighte n th e adjustin g nu t unti l th e rea r wheel s dra g
slightl y whe n turned .
6. Releas e th e parkin g lever , an d chec k tha t th e rea r
wheel s d o no t dra g whe n turned . Readjus t i f
necessary .
7. Wit h th e equalize r properl y adjusted , th e rea r
brake s shoul d b e full y applie d whe n th e parkin g
brak e leve r i s pulle d u p 1 0 t o 1 4 clicks .
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Front Brake s
Index/Inspectio n
• Neve r us e a n ai r hos e o r dr y brus h t o clea n brak e
assemblies .
• Us e a n OSHA-approve d vacuu m cleane r t o avoi d
breathin g brak e dust .
• Contaminate d brak e disc s o r pad s reduc e stoppin g
ability .
NOTE :
• Coa t piston , pisto n seal , an d calipe r bor e wit h clea n
brake fluid .
• Replac e al l rubber parts wit h ne w one s wheneve r
disassembled .
CAUTION:
• D o no t spil l brak e flui d o n th e car ; i t ma y damag e
th e paint ; i f brak e flui d doe s contac t th e paint ,
was h i t of f immediatel y wit h water .
• T o preven t spills , cove r th e hos e joint s wit h rag s
o r sho p towels .
• Clea n al l part s in brak e flui d an d ai r dry ; blo w ou t
al l passage s wit h compresse d air .
• Befor e reassembling , chec k tha t al l part s ar e
fre e o f dus t an d othe r foreig n particles .
• Replac e part s wit h ne w one s wheneve r
specifie d t o d o so .
• Mak e sur e n o dir t o r othe r foreig n matte r i s
allowe d t o contaminat e th e brak e fluid .
• D o no t reus e th e draine d fluid . Us e onl y clea n
DO T 3 o r 4 brak e fluid .
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6. Clea n th e calipe r thoroughly ; remov e an y rust , an d
chec k fo r groove s an d cracks .
7. Instal l th e pa d retainers .
11. Pus h i n th e piston s s o tha t th e calipe r wil l fi t ove r
the brak e pads .
12. Se t th e calipe r dow n int o position , the n instal l th e
brak e hos e mountin g bolt s an d th e calipe r moun -
ting bolts . Tighte n th e bolt s to th e specifie d torque .
8. Appl y Molykote ® M7 7 t o bot h side s o f inne r shi m
A an d th e bac k o f th e pads . Wip e exces s greas e of f
th e shims .
9 . Instal l th e brak e pads .
• Whe n reusin g th e pads , alway s reinstal l th e
brak e pad s i n thei r origina l position s t o preven t
los s o f brakin g efficiency .
• Contaminate d brak e disc s o r pad s reduc e stop -
pin g ability . Kee p greas e of f th e brak e disc s o r
pads .
NOTE :
• Instal l th e inne r pa d wit h it s wea r indicato r fac -
ing upward .
• Appl y Molykote ® M7 7 t o th e shim s (se e pag e
19-5 ). Wip e exces s greas e of f th e shims .
10 . Instal l th e brak e pa d shim s correctly . 13
. Depres s th e brak e peda l severa l time s t o mak e sur e
the brake s work , the n test-driv e th e car .
NOTE : Engagemen t of the brak e ma y requir e a
greate r peda l strok e immediatel y afte r th e brak e
pad s hav e bee n replace d a s a set . Severa l applica -
tion s of the brak e peda l wil l restor e th e norma l
peda l stroke .
14. Instal l th e fron t wheel s an d torqu e th e whee l nuts .
NOTE : Clea n th e matin g surfac e o f th e whee l an d
hu b befor e installin g th e wheel .
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Reassembly
CAUTION:
• Befor e reassembling , chec k tha t al l part s ar e fre e o f
dus t an d othe r foreig n particles .
• Replac e part s wit h ne w one s wheneve r specifie d t o
do so .
• Us e onl y clea n DOT 3 o r 4 brak e fluid .
• Mak e sur e n o dir t o r othe r foreig n matte r i s allowe d
t o contaminat e th e brak e fluid .
• D o no t spil l brak e flui d o n th e car ; i t ma y damag e th e
paint ; i f brak e flui d doe s contac t th e paint , was h i t
of f immediatel y wit h water .
1. Clea n th e piston s an d calipe r bore s wit h brak e fluid ,
and inspec t fo r wea r an d damage .
2. Appl y silicon e greas e t o ne w pisto n seals , the n in -
stal l th e pisto n seal s i n th e cylinde r grooves .
3. Appl y silicon e greas e t o ne w pisto n boots , the n in -
stal l th e pisto n boot s in th e cylinde r grooves .
4. Lubricat e th e calipe r cylinder s an d piston s wit h
brak e fluid , the n instal l th e piston s i n th e cylinder s
with th e dishe d en d facin g in .
5. Reinstal l th e calipe r i n th e revers e orde r o f removal .
6 . Fil l th e brak e reservoi r up , an d blee d th e brak e
system (se e pag e 19-10 ).
NOTE : A ne w dis c shoul d b e refinishe d i f it s
runou t i s greate r tha n 0.1 0 m m (0.00 4 in) .
Fron t Brak e Dis c
Run-Ou t Inspectio n
1. Rais e eac h sid e o f th e car , an d suppor t i t o n safet y
stand (se e pag e 1-9 throug h 1-11 ). Remov e th e fron t
wheels .
2. Remov e th e brak e dis c pad s (se e pag e 19-6 ).
3 . Inspec t th e dis c surfac e fo r crack s an d rust . Clea n
the dis c thoroughly , an d remov e al l rust .
4. Us e suitabl e nut s (1 2 x 1. 5 mm ) an d plai n washer s
to hol d th e dis c securel y agains t th e hub , the n
moun t a dia l indicato r a s shown .
Brake Dis c Runout :
Service Limit : 0.1 0 m m (0.00 4 in )
5. I f th e dis c i s beyon d th e servic e limit , refinis h it .
Max . Refinishin g Limit : 26. 0 m m (1.0 2 in )
Front Caliper
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Master Cylinde r an d Brak e Booste r
Index/Torqu e
BRAKE BOOSTE R
D o no t disassemble .
Tests , pag e 19-1 4
Pushro d Clearanc e Adjustment , pag e 19-1 5
MASTE R CYLINDE R
Inspection, pag e 19-1 3
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Master Cylinder

Inspection

CAUTION:

• Be careful not to bend or damage the brake pipes when removing the master cylinder.

• Do not spill brake fluid on the car; it may damage the paint; if brake fluid does contact the paint, wash it off immediate-

ly with water.

• To prevent spills, cover the hose joints with rags or shop towels.

• Before reassembling, check that all parts are free of dust and other foreign particles.

• Do not try to disassemble the master cylinder assembly. Replace the master cylinder assembly with a new part if

necessary.

• Make sure no dirt or other foreign matter is allowed to contaminate the brake fluid.

• Do not reuse the drained fluid. Use only clean DOT3 or 4 brake fluid.

• When connecting the brake pipes, make sure that there is no interference between the brake pipes and other parts.ProCarManuals.com

Brake Booste r
Tests
Functiona l Tes t
1. Wit h th e engin e stopped , depres s th e brak e peda l
severa l time s t o deplet e th e vacuu m reservoir , the n
depres s th e peda l har d an d hol d i t fo r 1 5 seconds .
I f th e peda l sinks , eithe r th e maste r cylinde r i s
bypassin g internally , o r th e brak e syste m (maste r
cylinder , lines , modulator , proportionin g valve , o r
calipers ) ar e leaking .
2 . Star t th e engin e wit h th e peda l depressed . I f th e pe -
da l sink s slightly , th e vacuu m booste r i s operatin g
normally , i f th e peda l heigh t doe s no t vary , th e
booste r o r chec k valv e i s faulty .
3 . Wit h th e engin e running , depres s th e brak e peda l
lightly . Appl y jus t enoug h pressur e t o hol d bac k au -
tomati c transmissio n creep . I f th e brak e peda l sink s
mor e tha n 2 5 m m (1. 0 in. ) i n thre e minutes , th e
maste r cylinde r i s faulty . A sligh t chang e i n peda l
heigh t whe n th e A/ C compresso r cycle s o n an d of f
i f normal . (Th e A/ C compresso r loa d change s th e
vacuu m availabl e t o th e booster. )
Leak Tes t
1. Depres s th e brak e peda l wit h th e engin e running ,
the n sto p th e engine . I f th e peda l heigh t doe s no t
var y whil e depresse d fo r 3 0 seconds , th e vacuu m
booste r i s OK . I f th e peda l rises , th e booste r i s faulty .
2 . Wit h th e engin e stopped , depres s th e brak e peda l
severa l time s usin g norma l pressure . Whe n th e pe -
da l i s firs t depressed , i t shoul d b e low . O n consecu -
tiv e applications , th e peda l heigh t shoul d graduall y
rise . I f th e peda l positio n doe s no t vary , chec k th e
booste r chec k valve .
Booste r Chec k Valv e Tes t
1. Disconnec t th e brak e booste r vacuu m hos e a t th e
booste r o r a t th e booste r sid e o f th e valve .
2 . Star t th e engin e an d le t i t idle . Ther e shoul d b e vacu -
um . I f n o vacuu m is available , th e chec k valv e is no t
workin g properly . Replac e th e chec k valv e an d
retest .
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