1998 HONDA CIVIC valve stem

Disassembly
CAUTION: The power steering components are made of aluminum. Avoid damaging the components during assembly.
NOTE:
. Ctean the disassembled parts with a solvent, and dry them with compressed air. Do not dip the rubber parts in a sol-
vent.
. Alwavs replace the O-rings and rubber seals with new ones before assembly.
. Apply recommended power steering fluid to the parts indicated in the assembly procedures'
. Do not allow dust, dirt, or other foreign materials to enter the power steering system.
. Replace the pump as an assembly ifthe parts indicated with asterisk (*) are worn or damaged'
FLANGE BOLTS20 N.m {2.0 kgf.m,14 rbf ft)
5 mm ROLLER
4.5 mm ROLLER
*OUTER SIOE PLATE
*SUB-VALVE
.PUMP NOTOR
}SIDE PLATE
l,/SNAP RING13 x 1.9 mm O-RINGReplace.
15.2 x 2.4 mm O-RINGReplace.
INLET JOINT
51 x 2.4 mm O-RINGReplace.
FLANGE BOLTS11 N m 11.1 kgf.m,8 rbf.ftl
PUMP SEALReplace.
PUMP SEAL SPAC€R
.PUMP DRIVE SHAFT
BALL BEARINGlnspection and RePlacement,see page 17-43
10 mm CIRCLIP
*FLOW CONTROI- VALVEInspection and Overhaul,se[ pase tt.tz g
4 --{;'rX!;'seatuc/ $
mm O-RINGPULLEY NUT6il N.m {6.5 kgf.m,47 tbf.frlFI-OW CONTROL VALV€ CAP49 N.m {5.0 kgt m,36 rb{.ft)
(cont'd)
17-41
J

)Reassembly
NOTE:
. clean the disassembled parts wrth a solvent, and dry them with compressed air. Do not dip the rubber parts in a sol-
vent.
. Always replace the O-rings and rubber seals with new ones before assembly'
. Apply the recommended power steering fluid to the parts+ndicated in the assembly procedures'
o Do not a||ow dust, dirt, or other foreign materials to enter the power steering system.
a Use the appropriate special tools where necessary'
FLANGE BOLTS20 N.m (2.0 kgt'm, 14lbf ftl
CYLINDER LINE B
VALVE HOUSINGFLARE NUTS
28 N.m (2.7 ksf m,20 lbf ftl
VALVE OIL SEAL
Replace.
CYLINDER END SEAL
Replace.
f itllTllli".",'r'o,.n,ft
''*^'*-1$*€-/s6-,,mode,3:
EUSHINGReplace 'P'\-- BEARING
SLEEVE SEAL RINGS ..-------...... SS
.----
",a"a,,
*---
--,
Replace. lss-, Replace.
Xll,Y5"l'.
"o. --r...- gY------..r.u,
,-f-..-S: _ ,96 _,9? models:
--€l€--------=- ircriip'ii.rt'-l./BACKUPReplace.
I,
wAvE wAsHER d
-.-.-r_ i"pru"".
CYLINDER HOUSING // -\-
, AJ - O.RING
/ ,S-'..- ReDtace.
_ j GEAR HouslNG l.g --'\-
\- t F
tonsrnrr
.,_- s
- 'oo ,,iod"t., -s-'--------- vALvE SEAL R'NG
S_.<---,tj- 97 models onlY:
CYLINDER END SEAL
)@OOD m n"prac".
/'\N,."._nrNG I '98 - 'oo - RACK GUIDE
models:
:scREw I
O.RINGReplace..98 - '00 models:
CYLINDER END69 N.m {?.0 kgt'm,51 lbl'ft)
(cont'd)
17-55
CYLINDER LINE A
tJ

Master Cylinder/Brake Booster
IRemovaUlnstallation
CAUTION:
. Be care{ul nol to bend or damage the brake lines when
rsmoving the mastsr cYlinder.
. Do not soill brakefluid on the vehicle; it may damage
the paint; if brake fluid does contact the paint, wssh
it off immediatelY with water'
. To prevent spill3, cover the hose ioints with rags or
shop towels.
9. Remove the four booster mountlng nuts
10. Pull the brake booster forward until the clevis is
clear of the bulkhead.
11. Remove the brake booster from the engine com-
panmenr.'12. Install the brake booster and master cylinder in the
reverse order of removal.
CAUTION:
. When connecting the brake lines. make sure
that there is no inte erence between the brake
lines and oth6r Parts.
r Be careful not to bend or damage the brake lines
when installing the master cylinder.
NOTE: lf replacing the master cylinder or brake
booster, check and adiust the pushrod clearance
be{ore installing the master cylinder (see page 19-221'
Fill the master cylinder reservoir, and bleed the
brake svstem (see Page 19-7).
After installation. check the brake pedal height and
brake pedal tree play (see page l9-5) and adjust if
necessary.
BRAKE BOOSTER(With ABS: 7" + 8" tandem brake booster)
BRAKE FLUIO LEVELSWITCH CONNECTORS
MASTER CYLINDER
VACUUM HOSE
1.
2.
3,
5.
Disconnect the brake fluid level switch connectors'
Remove the reservoir cap from the master cylinder'
The brake fluid may be sucked out through the top
of the master cylinder reservoir with a syrlnge.
Disconnect the brake lines from the master cylinder'
Remove the master cylinder mounting nuts and
washers.
\l/
6. Remove the master cylinder from the brake booster'
7. Disconnect the vacuum hose trom the brake booster'
8. Remove the cotter pin and clevis pin from the clevis'
CAUTION: Do not disconnect the clevb by remov-
ing it from the operating rod of the brako booster' lf
the clevis is loosened, adiust the pushrod length
before installing th€ brake booster (see page 19-221'
COTTER PINReplace.
To Rear Wheel Cylinders
14.
-6.4CLEVIS PIN
To Front Caliper(Without ABS)$
t'N't'ttrnt'-''
To Front CaliperlWithout ABSi
PBOPORTIONING CONTROL VALVE
15 N.m {1.5 kgl m,11 tbtft)
15 N.m {1.5 kgif.m, 11 lbtft}(With ABS: To modulator unit)lr
19-21

Brake Booster InsPection
FunctionalTest
1. With the engine stopped, depress the brake pedal
several times to deplete the vacuum reservoir, then
depress the pedal hard and hold it for 15 seconds lf
the pedal sinks' either the master cYlinder is
bypassing internally, or the brake system (master
cylinder. lines. modulator, proportioning control
valve, or caliPer) is ieaking.
2. Start the engine with the pedal depressed lf the
pedal sinks slightly, the vacuum booster is operating
normally. lf the pedal height does not vary, the
booster or check valve is faultY.
3. With the engine running. depress the brake pedal
lightly. Apply just enough pressure to hold back
automatic transmission creep. lf the brake pedal
sinks more than 25 mm (1.0 in.) in three minutes,
the master cvlinder is faulty. A slight change in
pedal height when the A'lC compressor cycles on
and off if normal. (The A/C compressor load
changes the vacuum available to the booster')
Leak Test
1. Depress the brake pedal with the engine running.
then stop the engine. lf the pedal height does not
vary while depressed for 30 seconds, the vacuum
booster is OK. lf the pedal rises. the booster is
faulty.
2, With the engine stopped, depress the brake pedal
several times using normal pressure When the
Dedal is first depressed, it should be low On con-
secutive applications, the pedal height should grad-
uallv rise. lf the pedal position does not vary, checK
the booster check valve.
l./
19-23
Booster Check Valve Test
1. Disconnect the brake booster vacuum hose at the
booster.
2. Stan the engine and let it idle. There should be vac-
uum. lf no vacuum is available, the check valve is
not working properly. Replace the brake booster
vacuum hose and check valve, and retest.
BRAKE BOOSTERVACUUM HOSE(Check valve
built-in)

t-Operation
t
ABS Control Unit
Main Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the vehicle
speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on the
rate of deceleration.
The ABS control unit calculates the slip rate of each wheel. and it transmits the control signal to the modulator unit
solenoid valve when the slip rate is high.
The pressure reduction control is a three-mode system, that is pressure reduction, pressure retaining and pressure intensi-
fying modes.
Self -diagnosis Funqtion
The ABS control unit is equipped with a main CPU and a sub CPU, and the CPUS check each other'
The CPUs check the circuit of the svstem.
When the CPUS detect failure, they shift to the "system down mode" or the "control inhibition mode"
The self-diagnosis can be classifield into these four categories:
O: Initial diagnosis
@: Except ABS control
@: During ABS control
@: During warning
On-board Diagnosis Funstion
The ABS control unit is connected to the data link connector {16P).
The ABS system can be diagnosed with the Honda PGM Tester.
(cont'd)
MODEABS INDICATOR LIGHTMAIN
RELAY
SOLENOID
VALVECPURestart conditionDTC
SYSTE IV
DOWNONNo
operation
Drive
inhibitionOperation*rlgnition
switchOFF + ONMemory
CONTROL
INHIBITIONONNo
operalron
Drive
inhibitionOperationAutomaticMemory
*1: Except CPU failure
/
19-47

Anti-lock Brake System {ABS)
Operation (cont'dl
ABS Modulator
The ABS modulator consists of the inlet solenoid valve, outlet solenoid valve, reservoir, pump, pump motor and thedamping chamber.
The modulator reduces the caliper fluid pressure directly, and it is also referred to as a circulating type because the brake fluidcirculates through the caliper, reservoir and the master cylinder.The hydraulic control has three modes: pressure reducing, pressure retaining, and pressure intensifying.The hydraulic circuit is the independent four channel type, one channel for each wheel.
RF LR
Pressure intensifying mode: Inlet valve open, outlet valve closed
Pressure retaining mode:
Pressure reducing mode:
Motor operation mode:
rN: INLETVALVE {NORMALtY OpENIOUT: OUTIET VALVE {NORMALIY CTOSED)Master cylinder fluid is pumped out to the caliDer.Inlet valve closed, outlet valve closedCaliper fluid is retained by the inlet valve and outlet valve.Inlet valve closed, outlet valve oDenCaliper fluid flows through the outlet valve to the reservoir.When starting the pressure reducing mode, the pump motor is ON.When stopping ABS operation, the pump motor is OFF.The reservoir fluid is pumped out by the pump, through the damping chamber, to the mastercvlinder.
PUMP MOTOR
19-48

ABS Control Unit Terminal Arrangement
ABS CONTROL UNIT 26P CONNECTOR
Wire side of temale terminals
Terminalnumo0rWirecolorTerminal signTerminalnamoDgscriptionVoltage
Conditions(lgnition Switch ON flt))Output voltagoteminals
PCOM(Primary
common)
Power source for the solenoidvalve and pump motor.1-GNDON
=ONOV
AC: 3-6 V
BLK/WHTscoM(Secondary
common)
Power source for the solenoid
2.GNDOFF
lConnect the SCS service\
conneclor lApprox. 3 V
ELVBLUtG2(lgnition 2)Detects ignition switch 2
!9nal. (system activate signal)3-GNDBatt€ry voltage
BLU/YELRRO(Rear-right 0)Detects right-rear wheelsensor signal.4-17
When the wheel isturned at 1 turn/second.
53 mV or above ondigitaltester (ACra nge) {Fefera nce)150 mvp-p or aboveon oscilloscope
6GRYRLO(Rear-left 0)Detects left-rear wheel sensorsrgnal.6-19
8GRNFRO(Front-right 0)D€tects right-front wheelsgnsor srgnal,a-21StopsApprox.2.5VSTOP(Stop)hects brake switch signal.(Prevents unnecess€ry ABS operation)9-GNDBrake pedal depressed.Battery voltage
Brake pedal released.OV
10BRN^/vHTFLO(Front-left 0)
Detects left-front wheel sensorsignal.
10-23
When the wheel isturned at 1 turn/secono.
53 mV or above ondigitaltester (ACrange) (Referance)
150 mVFporaboveon oscilloscope
9!opsApprox. 2.5 V
12YELRLOUT(Rearjeft outlet)
Drives left-rear outlet solenoid
12.GNDON-9ONOV
OFFAC: 3^6 V
REDMHTRR]N(Rear-right
inlet)
Drives right-rear inlet solenoidvalve.13-GNDOFF
lconnect the SCS service]i connector IApprox. 3 V
14B1(Battery 1)Power source for the solenoidvatve and pump motor.14.GND
Battery voltage15WHT/G R N82(Baftery 2)Power source for the solenoidvarve ano pump motor.15.GND
r6BLKGND2{Ground 2)Ground for the ABS controlunit.16-GNDBelow 0.3 V
17GRN/'/ELRR1(Rear-right 1)Detects right-rear wheelsensor signal.17-4
When the wheel is turnedat 1 turn/second.
53 mV or aboveon digitaltester(AC range)(Referance) 150mVp-p or aboveon oscilloscope
19LT BLURLl(Rea.-left 1)Detects left-rear wheel sensorsagnal.19-6
GRN/BLKFRl(Front-right 1)Detects right-front wheelsensor signal.21-8
FL1(Front-left 1)Detects left-front wheel sensorsignal.23-10StopsApprox. 2.5 V
REDRL-IN(Rear-lett inletl
Drives left-r€ar inlet solenoid
25.GND
ut
ON
'6
-9ONOV
OFFAC: 3-6 V
OFF
lconnect the SCS service] connector lApprox. 3 V
BLKGND3(Ground 3)Ground for the ABS cgntrolunit.26.GNDBelow 0.3 V
19-52

Troubleshooting Precautions
ABS Indicator Light
I The ABS indicator light comes on when the ABS control unit detects a problem in the system. However, even thoughthe system is normal, the ABs indicator light can come on, too, under the following conditions. To determine theactual cause of the problem, question the customer about the problem, taking the following conditions into consider-ation.
. Signal disturbance
. Wheel soin
. Only drive wheels rotate. Battery voltage fluctuates
2. When a problem is detected and the ABS indicator light comes on, the indicator light can stay on untat the ignitionswitch is turned off, or it can automatically go off, depending on the mode.. Lightstayson until the ignition switch isturned off;When the system is inthesvstem down mode.o Light automatically goes off:When the system is in the control inhibition mode.(refer to symptom-to-system chart)3 The ABS indicator light stays on when the system is reactivated without erasing the DTC, but it goes off after startingthe car.
when the wheel sensor system is faulty and the ABS indicator light comes on, the algorithm of the system automaticallyturns off the ABS indicator light after the wheel speed signal returns to the normal speed. while, when the DTC is erased,the CPU is reset and the ABS indicator light goes off when the system check€d out normal by the initial diagnosis.Therefore, test-drive the car after servicing the wheel sensor system, and be sure that the ABS indicator light does notcome on.
4. When the ABS control unit outputs battery voltage to the gauge assembty, the ABS indicator light goes off.
Diagnostic Trouble Code (DTC)
1. The diagnostic trouble code (DTC) is memorized when a problem is detected and the ABS indicator light does not gooff, or when the ABS indicator light comes on.The DTC is not memorized when the ABs indicator right comes on unress the cpU is activated.2. The memory can hold any number of DTCs. However, when the same DTc is detected twice or more, the later one iswritten over the old one.
Therefore. when the same problem is detected repeatedly, it is recorded as one DTC.3. The DTCS are indicated in the order of ascending number, not in the order thev occur.4. The DTCS are memorized in the EEpROM {non-volatile memorv}.Therefore, the memorized DTCS cannot be canceled by disconnecting the battery. perform the specified orocedures toerase.
Solf-diagnosis
1. The self-diagnosis can be classifield into these four categories:' Initial diagnosis; Performed right after the engine sta rts and untiltheABs indicator light goes off.o Except ABS control: Performed when the ABS is not functioning,. During ABS control: Performed when the ABS is functioning.. During warning: Performed when the ABS indicator light is ON.2 The system performs the following controls when a problem is detected by the self-diagnosis:. ABS indicator light ON. Memory of DTC
. Mode change to the "system down mode,, or the "control inhibition mode,,.
MODEABS INDICATOR LIGHTMAIN
RELAY
SOLENOID
VALVECPURestart conditionDTC
SYSTEM
DOWNONNo
operal|on
Drive
inhibitionOperation+rlgnition
switchOFF - ONMemory
CONTROL
INHIBITIONONNo
operat|on
Orive
inhibitionOperationAutomaticMemory
*1: Except CPU failure
19-54