1993 NISSAN SERENA lock

BMKE
SYSTEM
SECTIONBR
CONTENTS
PFECAUTIONS AND PREPARATION
AIB BLEEDING
CHECK
AND AOJUSTMENT
BFAKE HVORAUL]C LINE
SFAKE PEOAL
ANO BFACXET
LOAD
SENSING VALVE
VACUUM POSE
FFONT DtSC BFAKE (BD2AVA
AND LD23VB) .. ... ...... ......... .
BEAF OBJM BBAhE
PAHK]NO BBAKE CONTOOL
AN- LOCK ARAK '{G
SYSTTM
IBOUBLE OIAG\OSES .
SEHVICE OAl a
ANO SPECIFICAIIONS S.D S., . .. .... .

BRAKE
PEDAL AND BRACKET
Adiustment (Confd)
ll r.cssary, adjust bEke pedal
ffe€ haiqhl.
1. Loosn lock nui and adjust pedal
lBe h€iqht by trning
bnk6 bocre. inpul rod- Ihen tighlen lock nul.
M.lc .uE rhat dp ol Inplr rod srays In.lde .f clevl4
2. LoosEn lock nul and adlust deaEn€ "c
wilh stop lsmp
switch. Then tighton look nuts.
3. Ch€ck p€dal
l@e p
ay.
t{rke auE ih.l slop l.npl go
ofi w'En p€d.l
i3 €l.e.d.
4. Ch€ck bBk6 p.dsls
d.prBss€d hgighlwhile engine is run-
It depe$ed heighl is
below .p€cilied valu€,
ch€ck b6ke
systen lor l4ks, accumulaiion ol at or any damage to
conponenls (m$t6r
cylindBr, Blc.); lh6n make neessry
Bn-l4

FROiTT
D|sC BRAKE (BIr28vA
and LD2SV9)
Pad Replacement
1. Remove lower
Pin bolt
2. Swing cyinder body lpward. Then @move pad
€iain€b,
and inn€r and oul€r shims.
. Wh@
cyllnd€r body
b Mnq uA do not d€p|g bdt
p.dd b.ca@ pl.lon
wlll pop
ouf,
. B.
@F .or io dd.gE du.t @Er d g€t
ol! on reto.
Removal
. Remove
iorque member
lixing
boll. a.d union boll.
Disas9embly
Push od pislon
wilh du6l @v€r wilh @npre*ed an.
For LD23VB (2.p'sron
rype). u:e
a wooden block e rhal lhe
prslons com6 oul €v€.|y.
l
r,o.*
u t)ffi frl n
"oU
\J
BB-M

ANTI.LOCK
BRAKING SYSTEM
PurDose
. Ex@ssi@ braking in
any .ondilion (Dry
or w€t) wi I advers€ly atf€cl lh€ nomal llh ng ot lh6 v6hi'
oles wheels and they may
Lo.k
uP.
. whenlhe to.i wheels are lo.ked, a vehicle
ca.nol be controled by
lhe
sleenno syst€m.
. When
dre Garwhees are locked,lhe vehi.le wl enlerailalspin.
The A.B.S., by the lse ol eleclronc a.d hydraulic componenls, allows lor.onlrc of braking ior@ so
thal lockinq ot lhe wheels €n be avoided in the crcunstai@s des.rbed above.
1) Ensur€s prcper
lracking perfomance
lhrcuQh steefng wheelopealion.
2) Enabl6s obsiacles lo b€ avo d6d lhough sbenng who6lopeaton.
3) Ensur€6 vehicl€ slabilily by p6v6ntng
llat spins.
o s 0
$'
rFl ttEF-d
Yffi- "Wod
Ooeration
The A.B.S. is 6nlbll6d by an €laclbnic
@nlrolunit (E
C U.), whioh rece ves signals tom vafous s€n-
sors relalinq lo v€hi.le conditon.
speed, elc.
The hydraulc
circuit is
@nlrolled by an actuabr oontaining an e ecnc molof, pump,
accumllalor and
3
sole.oids. The E.C.U. dneds lhe aclualor to ncrease, hod or docr€ase hvdElli.
Dressure to
allor
Th6 E.C.U. rcc6iv€s inlomaton reqarding
wheelspeed trom senso6, houiled one pef
wh€€|.
When ex@ssiv€ takng
lorce
causes a whee b lock, the E.C.U. sends a sgnallo th6 acrualor ro
release the rocked
wlieer.
as the wheelu.lo.ks, l €n be steercd. The E.c.u. s.nses wh6elspeed is indeasng
and re-apples
hydGulic pressu€.
The wh6e locks aoain, is €leas6d, sleered,
baked, and so on. rhs @nlinuous
lock nq and unlocking oi
lhe whees
alos lor €pid speed reduction and the vehicl€ lo b€
6leeed in
Ths hydraulic pfgssurs€n
also b6 "h€ld" conslant
bya signalsenl lom the E.C.U. to lhe aclualof.
Th6 €ar wh€€ls utl26 a load's€nsing va ve
lo ilnher prcveni
whee ocking, especially undef min mum
However, when rhe vehicre
speed is ress
than l0 ktr/h (6MPH),
rhis sysl.m do6s nor wolk
BBSO

ANFLOCK
BRAKING SYSTEM
Operatlon (Cont'd)
i; !l
ii*
-ii
VEHICLE SPEED
. The appll€d bal@ @ndldon ls dp6ssEd by a slip €iio, s shown abova. ll lh€ slip
Etio i6
in th.
€ng€ lom 0.15 lo O.3, tha sh€.| hs ad€quarg coh€ nO p€rloma.@,
and d$ minimum siopplng
distan@ €n b€ achi€v€d.
. Th. srip 6rio lomula indi@r€s rhe @nrrcl ol wheel sp@d by rhe bEk6s.
The Aili-lock Sraklng Sysl€m (A-8.S.)
conlrcls b€k6lluid p@su€
usi.s th. 6lip ratios and lock-
Ing @ndlllon @lculaid ontain€d in rh. A.B-S. control unit.
. To adjusl whel sp€.d so lhrr fi6 oprinum 3lip htio
6 b. obiain.d, th. a,a.s, musi s6ns6 wh4l
3p4d sd v€hiolE sp.6d lhrcugh
a wh*l
.pe€d 5en6or.
ll lha bak
i6
appli€d, €speclally in lhe l@ked wh66l condirion, tE whicl6 sp@d
difi€c fom
th€
. All€r
lh6 wh€.| sp€6d chang€. l@n
th€ vohicle
sp*d due to ex@$lve brake for€, th6 A.B.S. dL
culat€s Ehicle.oe€d when lhe €du@d wh@l so4d @ch6s thB minimum.
VEHICLE
SPEED -
WHEEL SPEED
BB-€1

ANI}LOCK
BRAKING
SYSTEM
System Components
System Descriplion
SENSOF
Th6 sercof unil corcbb ol6 q€aFshgp.d
blor.nd a sensor
alamenl which
conlain6 a bar magnel
around which a coil is
wound. The sener is insialled on the back side ot lh6 b€k€
rotor. sin6'wav€ curent is g.neEted
by lhe sn.or a5 lhe
wh€€l rolale6.
Th. l@quency
and vollage inc€ase(s) as lhe
eialina speed inc€ases,
CONTBOL UNIT
Th. @ntrc! unit computes the oiating speed ol ihe wheet by
ihe siqnalcunentsenl fbn the *nsor, and supples a Dc cur
renl lo the a.iuaior solenoid valve provided
lor each lonr whe6l
and rear a e by cha.g ng its intemal resisla.€. ll also @ntrcl.
ON-OFF operaiion oi the valve rclay and pump
r6lay. ll any
6l6crric.lly d.reciable malluncrion
sholld odur in the system,
ihe contDl unir €uses the waning liqhr ro light up. In lhE
conditio., lhe A.B.S. wil be deaclival.d bv lh6 @ntrol
unt, and
the v6h cls s b€king sr€l€m r6v6ns
b noma
opeElion,
BR-32

AI{T|.LOCK
BRAKING SYSIEII
System De€crlplion (Coni'd)
ACTUATOR
o
@
@
@
o
o
o
o
J@
@
Th6 actuslor consisrs
or solenoid valves, a pump,
rcs.tron (brp€ssuB
decreasi.g), a.d adamperand
orilice (lo
pevent
hrgh pressu
6 llud pEouced
bv fe oLnp lron oeng appked to rh€ n4t€r
ct-
nd6r). rh6
$l€rod wlv. +.rqe6 it6
6poolpos'hon @respoad ns ro rr€ 6ntbtunt
oubut amperr-
q.: il lom6
a p€56!@
decreaslng circuit at abour 5 amp6e6.
a pfesure
holding onclir al aboul 2
amp€Fs, and a p@ssure
Increasing circuit 51 0 amp6res.
when ihe p€ssurc
d€crcas no cn@t is
tom€d, |he bdke fuld in the @liperflows inlo lh6 €sedoir
a.d lhe pG$!re
drops- Th6 plmp
d€l-
ve6 lhe iluid lo the dafrper and the odiica
to €du@ tluld
Dre$u@, belorc
irs r6tun ro
lhe m$ter
cv-
hnder. When rh€ p,€surc
holdirq crrcu
I 's
lortred,
fte catrper rin€
is cut of, .nd th€ ,u
d oe$Lre i"
lhe €liod is k€Dl
conslant.
BR-3il

AI.I]]-LOCK
BRAKING SYSTEM
S'yslern De6cription (Cont
d)
CONTBOL UNTI CONTFOL CHART
a
BR-34