Valve ACURA INTEGRA 1994 Service Repair Manual

Pressure Relief
Pressu.6 outside of the metering orifice is directed to
the bonom ot the flow control valve. When the pressure
builds up, the reliet valve in the flow control valve opens
to relieve the pressure. As the flow control valve is
pushed back by the pressure difference this time, the
flow of fluid in the bypass passsge increases, convolling
the pressure outside the metering orifice. The above
operations are repeated to provide constant discharge
prsssure lrom the pump,
VALVE
{Dacrarlai cxco33ivaYibration in iha valva.l
(cont'dl
17-7

System Description
Steering Gearbox
The rack-and-pinion type steering gearbox has a valve unit incorporated with the pinion to control the steering fluid pres-
sure. Steering fluid from the pump is regulated by a rotary valve in the valve unit and is sent through the cylinder pipe to
the power cylinder, where hydraulic pressure is applied. The steering fluid in the other side of the power cylinder returns
through the cylinder pipe and valve unit to the reservoir.
VALVE UNIT
CYLINDER PIPE
POWEB CYLINDER
Valve Unit
Inside the valve unit is the valve, which is coaxial with the pinion shaft, and controls the steering fluid pressure. The valve
housing is connected with the fluid pipe from the pump, return pipe to the pump, and the two cylinder pipes from the
respective power cylinder.
The pinion shaft is double - structured with the input shaft connected to the pinion gear, both of which are interconnected
with the torsion bar.
The pin insened in the valve and the pinion shaft groove engage; this allows the pinion shaft to rotate together with the
Because of this construction, the difference in angle in the circumferential direction between the input shaft and the valve
becomes larger according to the torsional strength of the pinion or steering resistance. However, maximum torsion
between the shafts is regulated by the engaged splines of the shafts at the pin engagement section to hold the torsion bar
within the set value.
This allows the steering system to lunction as an ordinary rack-and-pinion type steering if the steering fluid is not pressur-
ized because of a faulty pump.
VALVE
Difforcnco in .ngl. bo{w€cn thainput shalt rnd pinion !h.tt
ln-1
B
lEngag€ with the pinionshaft groove)

17-8
INPUT SHAFT

Pressure Control
Low assist at higher speeds:
When steering resistance is low. such as when driving at high speeds. or when driving straight ahead, the input shaft is
near or in the neutral position, so there is little or no flow to any of the power cylinder orifices, Most of the feed pressure
trom the pump is bypassed to the reservoir. Because of this, the pressure stays the same in both sides of the power cylin-
der, resulting in low or no assist.
vaz =- S\->/-\7/RETURN PASSAGE(To RESERVOIRI
VALVE UNITINPUT SHAFT
High assist at lower speeds:
When steering resistance is high, such as when driving at low speed, or when turning the wheel with the car stopped, the
difference in angle created between the input shaft and the valve opens the fluid passage on one side, and closes the fluid
passage on the other side, at each pair of orifices. The fluid pressure increases in the side of the power cylinder fed by the
larger 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 the
input 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 and
power assist decreases when the steering effort would normally be low, (for example, when driving at high speeds or
straight ah€ad).
FLUIO PASSAGE TOPOWER CYLINDERFrom PUMP
A
/t-:\
v"
=iJ
RETURNPASSAGE
FLUID PASSAGE FROMPOWER CYLINDER
ALVE F.om PUMP
RESERVOIR

Troubleshooting
General Troubleshooting
Check the following betore you begin:
. Has the susp€nsion been modified in a way that would affect steering?. Are tire sizes and air pressure correct?
. ls the steering whe€l original squipment or equivalent?
. ls the power steering pump belt properly adiusted?
o ls steering fluid reservoir filled to proper level?
o ls the engine idle speed correct and steady?
Normal reliel pressure
I
I
Go to pate tu.l t
r Fluid pro$ure is too low:Chock th€ rgturn circuit pipe and hose between thogearbox and pump tor clogging and dotormation.* Fluid pressure is too hioh:Check the pipe and hosg connected from th6 pumpto tho georbox tor clogging and delormation.
Check pump fluid pressurg (soepage 17-221,Measure steady-state fluid pres-sure while idling with the shut-offvalve fully open.Ir shoutd be 1,500 kPa (15 kgtcm', 213 psi) or bolow.
Normal
Check pump fluid pr€ssur€ {se€page 17-221.Measure pump relief pressurewhile idling with the shut-offvalve fully closod.h should be 6,400 - 7,400 kPa {65- 75 kgtcm,, 924 - 1,067 psi)
Check the flow control valve.* Check lhe valve for smooth movement in thg hou6-Ing.* Chock thg reli€f valve for leaks.
Abnormal
I
I
Faulty flowtontroi valve
17-10

Unovon or rcugh 8te6ring.
3
Adjust rack guide (se€ poge 17-21).
ll the probl6m is not corrected bYadjusting lhe rack guide. replacothe gearbox.
Adiud bolt t€nsion. Roplace b€lt, ifn€c€ssary {s€e page 17-20).
lf the ongin€ stalls when wheel isturned whil€ car is stoDPed ormoving at low spoed, adjust idlesp€€d (soe section 1 1 ).
ldl6 soosd low or orrrtic.
Chock power sieering Iluid levol. Itlgv6l ie excessivoly low, ch€ck forleaks in the system. Add fluid totho spocifiod level.
Air in rssorvoir. or ch€ck pow6a
steoring fluid l6v6l.
lf fluid lev6l is OK, check o-ringsand seals on both €nds of ihopump inlet hose, and th€ oilpump housing mating surfacosfor suction leaks. Reolace oarts65 n€CeSSAry.
Adjust belt tonsion (see page 17-m) or r€Dlaco beh.Pump b6lt slipping on pull6y(pump stops momontarily).
Check if pump prossure is withinthe ranoe 6.400 - 7,100 kPa (65 - 75kgr/cm,, 924 - 1,067 psil and th6gsuge needls travol is 1500 kPa {15kgflctn2, t71 p6i) or less. Check theflow control valve if the needletr.vel €xcoods 1500 kPa {15kg?cm,, i71 psi). lf rhe flow controlvalvo is normal, replace th€ pump
as an assomblv.
Sel the power itooring p.oasuregaug6. Cl066 th€ shut-off v6lv6fully and m€a5uro tho pumppr6ssur6 (6s€ pagg 17-221,
7-1

Troubleshooting
Noise and Vibration
NOTE: Pump noise in first 2 - 3 minutes after starting in cold weather (-20.C, -4"F or colder) is normal.
Humming
Rattle or chattering
Right cylinder end soal squeak
Pump noise. though not loud,lrom the vslvo bodv unit can be heard when turn-ing the steering wheel right or left. This is normsl.
Humming due to pulsation ol fluid is no.mal, paniculady when wheel is turnedwith ca. stopped.
lf equipped with automatic trans-mission, the hum could b€ tor-que convener or pump notse.
Confirm by temporarily removingpump b€lt.
High pressure line touching theframe,Reposhion tho line.
Loose steering shaft connector.tie-rod, or balljoint.Check and tighten, or replacepa s as necessary.
Column shaft wobbling.Replace column assembly.
Check the rack guide for properadjustment (16o page 17-21).Adjust, if n€ca€ssry.
Rattling sound and feeling when turning the steoring wheel right and lett with thoengine OFF is a sound when th6 valve unit contacts tho stopper. This is normal.
Striking sound wh6n turning the ste€ring whoglfully right o. left is a sound whenthe r6ck end contacts th6 stopper. This is normal.
17-14

Troubleshooting
Fluid Leaks
Check the gearbox assembly for oil leaks carefully. Oil can leak out of various points. depending on location of thefaulty oil seals/seal rings. Check the following before removing the gearbox from the frame.
Steering GearboxLeaking from the oil seal on thetop of the valve housing.Roplace the valve oil seal fromthe valve housing.
Leaking from cylinder end intoleft tie'rod boot.Replace the valve oil seal lromthe pinion shaft.
Reolace the cvlinder end seal.
Leaking from cylinder end intoright tie rod boot.
Tighten attaching bolts or replacethe valve body unit or gear hous-Ing.
Leaking from the vslve bodyuniVhousing mounting soction.
Tighten connector. It still leaking.replace the pipe, cylinder orvalve housing unil.
Leaking from cylind6r pipe A or Bconnection (at tlare nut).
Leaking caused by damaged cy-linder pipe A or B.Replace the cylinder pipe A or B.
Leaking from feed pip6 andreturn pipe of the valve body unit(at flare nut).
Tighten connector. lI still leaking,replace the pipe or valve housIn9,
17-16

lnspection and Adjustment
Pump Pressure Check
Check the fluid pressure as follows to determine
whether the trouble is in the pump or gearbox.
NOTE: First check the power steering fluid level and
pump belt tension,
CAUnON: Dilconn€st the high pros3uro ho3s with cale
!o e3 not to spill tho powor stooring fluid on th6 lramo
lnd olhor parG.
1. Disconnect the outlet hose from the oumo outlet fit-
ting, 8nd install the pump joint adapter on the
pump outlet.
2, Connect the hose joint sdapter to the power steer-
ing pressure gauge, then connect the outlet hose to
the adaotor.
3. Instsll the power steering pressure gauge to the
pump joint adaptor as shown.
OUTLET HOSE FlTnNG
HOSE ATTACHING BOLT1l Nm11.1 kg{ m 8lbf.ftl
6 x 1.0 m.n BOLT{P!rt of tooll11 N.m11.1 kgtm,8lbf.ftl
P/S JOINT ADAPTOR IPUMPIo?NAK - SmolrA
PUMP OUTI.TTFITIING
Open the shut-off valve fully.
Open the pressure control valve fully.
17 -22
1.
Start the engine and let it idle.
Turn the stee.ing wheel from lock-to-lock several
times to warm the fluid to operating temperature.
Measure steady-state fluid pressure while idling
with the shut-off valve fully open. lf the pump is in
good condition, the gauge should read less than
1500 kpa (15 kgf/cm,,213 psi).
lf it reads high, check the feed line or valve body
unit (see General Troubleshooting l7-10).
Close the shut-off valve. then close the pressure
control valve gradually until the pressure gauge
needle is stabl6, Read the pressure.
lmmediately open the shut-off valve fully.
CAUTION: Do not keep the shut-ott valvs closod
moro thgn 5 soconds or th9 pump could b6 dam"
agod by over-h6ating,
lf the pump is in good condition, the gauge should
read at least 6.400 - 7,400 kpa (65 - 75 kgIlcm,,924- 1,067 psi). A low reading means pump output is
too low for full assist. Repair or replace the pump.
10.
P/S PRESSURE GAUGE

Fluid Leakage Inspection
BOOTCheck lor leaks.
GEARBOX rnd VALVE BODY UNITCheck for leaks at the mating surfaceand rlare nut connections.
PUMP ASSEMBLYCh€ck for leaks at the pumpseal, inlet and outlet fiftings.
Inspect hoses for d6mage, leaks,interference or tlvisting,Inspect fluid lines for damage,rusting or leakage.Inspect for leaks at hose andline ioints or connections,
17-23

Power Steering Pump
Disassembly (cont'dl
Flow Gontrol Valve Removal/lnspoction
l. Rsmove the control valve cov€r by romoving thethree flange bolts.
2. Remove the spring, flow control valve and O-rings.
FLOWCONTROL VALVE
Check the flow control valvg for wgar, burrs, andother damage to the edges of th€ groovos in tho
FLOWOONTROL VALVE
Ch6ck fordamags to €dgos.
17-36
il. Inspect the bore for the flow control valvs for scrat-ches or wear.
5. Slip the valve back in the pump and chock that itmoves in and out smoothly.
- lf OK, go on step 6, if not replace th6 valve androchsck the valve movsment.
NOTE: The original valve was selected for a precise
fit in the pump housing bore, so make sure ths n€w
on6 has the same identification mark.
Outsid€ Oiam€ter
- lf the valve movement still incorr€ct, replaco thepump as an assembly.
6. Attach a hose to the end of the valve as shown.
HOSE
MarkPart NameOutside Diameter
mm (in)
AFLOW CONTROL
VALVE A
17.991 - 17.996(0.7083 - 0.7085)
FLOW CONTROL
VALVE B
17.996 - 18.001
{0.7085 - 0.7087}
FLOW CONTROL VALVE