1998 ACURA INTEGRA Service Repair Manual

INPUT SHAFT
High assist at lower speedsl
When steering resistance is high, such as when driving at low speed, or when turning the wheel with the car stopped, the
diiference in angle created between the input shaft and the valve opens the tluid passage on one side, and closes the fluidpassage on the other side, at each pair of orifices. The fluid pressure lncreases in the side of the power cylinder fed by thelarger fluid passage. This increased pressure pushes on the rack piston, allowing the steering wheel to be turned with light
effon. On the other side of the power cylinder, the return passage opens allowing the steering fluid to return through theinput shaft to the reservoir. The fluid passages to the power cylinder automatically change in size, increasing as the steer-ing resistance increases. In other words, the passages become larger and power assist increases when the steering effort
would normally be high, (for example, when parking or making low speed turns), and the passages become smaller andpower assist decreases when the steering effort would normally be low, (for example, when driving at high speeds or
straight ahead).
FLUIO PASSAGE TOPOWER CYLINDER
Ce) r.r;
VK
Pressure Control
Low assist at higher speedsl
When steering resistance is low, such as when driving at high speeds, or when driving straight ahead. the lnput shaft is
near or in the neutral position, so there is liftle or no flow to any of the power cylinder orifices. Most of the feed pressure
from the pump is bypassed to the reservoir. Because of this, the pressure stays the same in both sides of the power cvlin-
der, resulting in low or no assist.
RETURN PASSAGE{To RESERVOIR)
POWER CYLINDERlHigh fluid pressurelI
ALVE FTom PUMP
RESERVOIR
SECTION A-A
17-9

Troubleshooting
General Troubleshooting
Check the following before you begin:
o Has the suspension been modified in a way that would affect steering?
. Are tire sizes and air pressure correct?
. lsthe steering wheel original equipment or equivalent?
. ls the power steering pump belt properly adiusted?
. ls steering fluid reservoirtilled to proper level?
. ls the engine idle speed correct and steadyT
Hard steering (check the power assist, see page 17-18. It the torce is over 34 N (3.5 kgf, 7 7 lbf), proceed with this troubl*hooting l
Abnormalfluidpressur€ (lluid
pressure rs roohish)
Too low reliefpress{ire
Normal line and hos6
I
II
iFaulty valve body unit
Normal Abnormal
rlrl
l{
Faulty pump assembly Faulty tlow control valv6
Ch€ck the tegd and return circuit lines and hoso
between the gearbox and pump for clogging and
detormation.
Check pump fluid Pressuro {sespage 17'221.Mgasure stoady-stat€ fluid Pres_sure while idling with the both
valv6Iully opon.It should be 1,500 kPa (15 kgf/
cm,,213 psi) or below.
Normal
Check the flow control valve (seo page 17-37).. Check the valvs Ior smooth movemont in the hous-
Ing.. Check tho reliel valvo for leaks.
Measure pump reliet prgssure
while idling with the both vslveIully closed.It should b€ 6,400 - 7,400 kPa {65- 75 kgt/cm', 924 - 1,067 psi)
Normal reliel pressure
I
I
+
Go to pags 17-11
17-10

From page 17-10
Normal
Check lorce required to turn thewhool (see page 17-'18).Start the engine and measu16the force required to turn thewheel to the right and left.Difference of the force requiredto twn the wheel to the right andto the left should be 5 N (0.5 kgf,1 lbl) or below.
Deformed
I
iFaulty cylinder lines
Not bent
Adjustment OK
Faulty valve body unit
Abnormal --> Faulty gearbox
Ch€ck th6 pans other than the gearbox-related parts lorDrooer rolaton.
. . lmproper rotation ofthe steering column-related pan{s}----------------- . tau[y $eenng lornt. Faulty rack endtio-rod ond balljoints. Intgrferonce in the steering system
Normal -----> lmproperly adjusted rack guide
Check lor bent rack shaft.
Check pump fluid pressure (seepage 17-22).Turn the steoring wheel fully tothe right and l€ft while idlingwilh the pressure control valveIully open, and measure the Iluidpressure. lt should be 6,400 -
7,400 kPa (65 - 75 kgflcmr, 924 -
1,067 psi).
Normal
Ch€ck the gearbox.Remove the gearbox and mea-sure the pinion torque.The lorque should be;. 0.7 - '1.2 N.m (7 - 12 kgf.cm, 6 -
10 lbf.in) wjth the steering rackin the straight driving position.
Abnormal
Adjust the rack guide {see page17-211, and recheck the pinion
torque.
17-11

Troubleshooting
General Troubleshooting (cont'dl
Assist (excessively light steering) athigh speod.
Shock or vibration when wheel isturned to full lock.
Steering wheel will not return
smoothly.
a-, aa GrI r- tz
ll the problom is not correcled byadiusting the rack guide, adjustthe front wh66l alignment (see
s6ction 18).
Ch6ck th6 rack guide propgr ad-justment (see pago 17-21).
Check the rack guido lor proper
adjustment (see page 17-21).
Rack guid€ is adjusted properly.
lf the problem is not corrected byadjusting the rack guide, replscothe gearbox.Check the belt for slippage andadjust as nec€ssary {s6e page 17-20).
A and B cylinder lines are nor-mal, chgck wheol alignment (se€
section 18).
Whe6l alignment is abnormal,adjust as needod.
It should be 0.7 - 1.2 N.m {7 - 12kgl.cm.6 - 10 lbf.in) or belowwith the steering rack in thestraight ahoad driving position.
wh€el alignment is normal.R€mov€ the gearbox from thofram6 snd measure the pinion
torque on the gearbox.
lf the measurements are out ofsp€cifications. adjust the rackgurd9.
It the problom is not corrected byadiusting the rack guido. r€placethe goarbox.
{
I

Unev€n or rough steering.Adjust rack guid€ (see page 17-21).
It the problem is not corrocted byadjusting the rack guid€, replacethe g€a.box.
Adjust b6ll tension. Ropl6ce theb6lt, it necossary {s€e p€ge 17-20).
lfth€ engine stalls when the wheelis turned while the vehic16 isstopped or moving at low speed.adjust idl6 sp6od (s€e s€ction 111.
ldle spoed low or €rratic.
Check powsr st6oring fuid lovel. lfthe lovel is exceggively low, ch6cktor leaks in the svstem. Add fluidto the sD6cilied l6v6l,
Air in r€gervoir, or check powsr
steering fluid lovel.
lf fluid level is OK, chock O-ringsand seals on both 6nds ot thepump suction hose. and the P/Spump housing mating surfacesand tho oumo shaft oil seal forsuction lgakr. Roplaco parts asn6c6ssary.
Pump b€lt slipping on pulloy(pump stops momentarily).Adiust b6lt t€nsion {s6e page '17-
20) or r6olac€ b€lt.
Chock if pump pressure is normaland the gauge needle trav€l is 500kPa (5 kgl/cm', 71 psi) or lesB.Ch€ck the flow control valvo if theno€dl€ trav€l oxco€ds 500 kPa {5kg7cml, 71 p6i). lf the flow controlvalve is normal. roplace the pumpas an assemDtv.
Install the power st66ring pr6s-
su16 gaug6. Close th6 prossure
control valve lully and m6asurethe pump prossure (see page'17-22t.
Ste€ring wheol kicks backduring wide turns.
7-13

I
Troubleshooting
17-14
Noise and Vibration
NOTEr Pump noise in first 2 - 3 minutes after starting in cold weather is normal.
Humming
Rattle or chattering
Humming due to pulsation oI lluid is normal, particularly when the wheel isturned with the vehicle stoooed.
Outlet hose (High-pressure hose)touching the frame.
Right cylinder end seal squeak.
Pump noise, though not loud, from tho valv6 body unit can be heard when turn-ing the steering wheel to full lock in either direction. This is normal. Do not hold
the steering wh6el at tull lock tor more that live seconds wh€n inspecting.
Loose steering shaft connector,tie-rod, or ball ioint.
Check and tighten, or replacepans as necessary,
Column shaft wobbling.Reolace the column assemblv.
Check ihe rack guide tor proper
adjustment (see page 17-21).Adiust, if nec€ssary.
Rattling sound and feeling when turning the steering wheel right and left with the
engine OFF is normal.

Pump noiseGrating noisefrom pump
Pump noise
I
aou""*,nn
Rattle or chattering
Check the flu id level.lf low, fill the reservoir to theproper level, and check for leaks.Tighten or replace as necessary.
Cavitation caused by air bubblesin the fluid.
Check for a crushed inlet hose ora loose hose clamp allowing airinto the suction side of the sys-tem.Tighten or replace as oecessary.
Check the oumo shaft oil seal.
Check the reservoir for cracks.
NOTE: Pump noise up to 2 - 3minutes alter starting in coldweather is normal.Compare pump noise at operat-ing tomperature to another simi-lar vehicle.
lf pump noise is abnormally loud,remove and inspect the pump forwear and damage (see page 17-36).
Tighten or replace the pulley.lf shaft is loose, replace thepump.
17-15

Troubleshooting
Fluid Leaks
Check the gearbox assembly for oil leaks carefully, Oil can leak out of various points, depending on location of the
faulty oil seals/seal rings. Check the following before removing the gearbox from the frame.
Stoo.ing GearboxReplace the valv€ oil seal fromthe valvo houging.Leaking from the oil seal on thetop of the valve housing.
Roplace the valve oil seal fromthe pinion shaft.Leaking trom cylinder 6nd intol€ft ti6-rod boot,
B€place tho cylindgr ond seal onthe gear housing side.
Replaco th€ cylindor end seal onths cylinder end side.Leaking from cylinder end intoright tie-rod boot.
Leaking from the thaft upper endsection or pin ongagement sgc-tion ofth6 Dinion shaftRoDlace tho valve bodv unit.I
I
Tighten connector. lf it€ still leak-ing. replace th€ lin€, cylinder orvalve housing.
Leaking lrom cylind6r line A or Bconn6ction {Et flare nut).
Leaking caused by a damagedcylinder line A or B.Replace cylinder line A or B.
Tightgn tho connector. ll its stillleaking, r€place the hos€, joint
fitting or valv€ housing.
Leaking from outlet line andreturn line joint fitting on thevalv6 body unit (at flare nut).
17-16