Page 849 of 1395
Troubleshooting
General Troubleshootin g
Check the following before you begin:
. Has the suspension been modified in a way that would affect steering?
. Are tire sizes, tire variety and air pressure correct?
. ls the steering wheel original equipment or equivalent?
. ls the power steering pump belt properly adjusted?
. ls steering fluid reservoir filled to proper level?
. ls the engine idle speed correct and steady?
Hard Steering (Check the power assist, see page 17-12. lf the force is over 29 N (3.0 kgl 6.6 lbfl, proceed with this troubleshooting.i
Abnormalthiidpressure (Iluidpressure is toohigh)
Relief pressuretoo low
Faulty valve body unit
Abnormal
Check the teed and return circuit lines and hosebetween the gearbox and pump for clogging anddeformation.
Normal line and hose
Check the pump fluid pressure(see page 17-16 or 17-17).Measure steady state lluid pres-
sure at idle with the pressure con-trol valve and the shut-off valve (it
so equipped) fully open.The fluid pressure should be 1,500kPa (15 kgf/cm,,213 psi)or less.
Normal
Check the flow control valve (see page 17 26).. Check the valv€ lor smooth movement in the hous-ing.. Check the relief valve for leaks.
Check the pump fluid pressure(see page 17-16 or l7-17).Measure pump relief pressure atidle with the pressure controlvalve and the shut'off valve lil soequipped) fully closed.The fluid pressure should be 6,9007,800 kPa (70 - 80 kgflcm,, 1,000- 1,140 psi).
Normal relief pressure
17-4
Go to page 17 5Faulty pump assemblyFaulty flow control valve
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Page 852 of 1395
Uneven or rough steering.Ad,ust the rack gu ide (see page 17- 15).
ll the problem is not corrected byadjusting the rack guide, replacethe gearbox.
Adjust the belttension. Replace thebelt, if necessary (see page 17-14).Belt slipping on pulley.
lf the engine stalls when thewheel is turned while the vehicleis stopped or moving at lowspeed, adjust the idle speed (seesection 111.
ldle speed low or erratic.
Check power steering lluid level. lfthe level is excessively low checkfor leaks in the system. Add fluidto the specified level.
Air in reservoir, or check powersteering tluid level.
lf fluid level is OK, check O-ringsand seals on both ends of thepump inlet hose, and the P/Spump housing mating surlacesand drive shaft oil seal for suction leaks. Check the reservoir forcracks, Replace parts as neces-
Pump belt slipping on pulley(pump stops momentarily).Adjust the belt tension (see page17-14) or replace belt.
Check if pump pressure is normaland the gauge needle travel is 500kPa (5 kgl/cm,, 71 psi) or less.Check the flow control valve if theneedle travel exceeds 500 kPa (5kgflcm' , 71 psi). lI the flow controlvalve is normal, replace the pumpas an assembly,
Install the power steering pres-sure gauge, Close the pressurecontrol valve and shut off valve (if
so equipped) fully and measurethe pump pressure (see page 17-16ot 17 17).
Steering wheel kicks backduring wide turns.
7-7
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Page 861 of 1395
lnspection and Adjustment
Pump Pressure Gheck With T/N 07406 - 0010001
Check the fluid pressure as follows to determine whetherthe trouble is in the pump orgearbox.
1. Check the powsr steering fluid level (see page 17-15), and pump belt tension (see page 17-14).
2. Disconnect the pump outlet hose from the pump
outlet with care so as not to spill the pow€r steeringiluid on the frame and other pans. thon install theP/S joint adapter (pumpl on the pump outlet.
6 x 1.0 mm BOLT{Part oftool)
FEED HOSE FITTING
PUMP OUTLET HOSE
11 N.m ll.1 kgl.m, E lbf.ftl
P/S PRESSURE GAUGE07('6 - 0010001
6 x t.0 mm BOLT{Part oftool)11 N.m(1.1 kgt m, 8 lbf.tr)
Connect the P/S joint adapter (hose) to the p/S pres-
sure gauge, then connect the pump outlet hose tothe P/S ioint adspter (hose).
Install the P/S pressure gauge to the p/S joint
adapter (pump),
17-16
5. Fully open the shut-off valve.
PRESSURECONTROL VALVE
6. Fully open the pressure controlvatve.
7. Start the engine and let it idle.
8. Turn the steering wheel from lock-to-lock severaltimes to warm the fluid to operating temperature.
9, Measure steady-state fluid pressure while the engineis idling. lf the pump is in good condition, the gauge
should read less than 1,500 kPa (15 kgf/cmr, 213 psi).
lf it reads high, check the outlet hose or valve bodvunit (see General Troubleshooting).
10. Close the pressure control valve, then close theshut-off valve gradually until the pressure gauge
nsedle is stable. Read the pressure.
CAUTION: Do not k€ap tha prca3un control valvoclorod mo.c thon 5 srconds or thc pump cluld bodamEgod by ovor-hoating.
11. lmmodiately open the pressure controlvalve fullv.
lf the pump is in good condition, the gauge shouldread at least 6,900 - 7,800 kpa (70 - 80 kgflcmr,'1,000 - 1.140 psi). A low reading means pump out-put is too low for full assist. Repair or replace theDUMD.
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Page 862 of 1395
Pump Pressure Check With T/N 07406 -
Check the fluid pressure as follows to determine whether
the trouble is in the pump or gearbox.
1. Check the power steering tluid level (see page 17-
151, and pump belt tension (see page 17-14).
2. Disconnect the pump outlet hose from the pump
outlet with care so as not to spill the power steering
fluid on the frame and other parts, then install the
P/S joint adapter (pump) on the pump outlet.
6 x 1.0 mm BOLT(Part oftool)
FEED HOSE HfNNG
PUMP OUTLET HOSE
1'l N.m 11.1 kgf.m,8lbf ft)
P/S PRESSURE GAUGE07406 - 001000A
6 x 1.0 mm BOLT(Part ol tool)11 N.m(1.r kg{.m,8lbf'ft|
Connect the P/S joint adapter (hose) to the P/S pres-
sure gauge, then connect the outlet hose to the P/S
joint adapter (hose).
Install the P/S pressure gauge to the P/S joint
adapter (pumpl.
001000A
5. Open the pressure controlvalve fully.
PRESSURECONTROL VALVE
7.
10.
Start the engine and let it idle.
Turn the steering wheel from lock-to-lock several
times to warm the tluid to operating temperature.
Measure steady-state fluid pressure while the engine
is idling. It the pump is in good condition, the gauge
should read 1,500 kPa (15 koflcm' ,213 psi). lf it reads
high. check the outlet hose or valve body unit {see
General Troubleshooting),
Close the-pressure control valve gradually and read
the oressure.
CAUTION: Do not keep the pressurs control valve
closed more then 5 seconds or the pump could bo
damaged by overheating.
lmmediately open the pressure controlvalve fully.
lf the pump is in good condition, the gauge should
read at least 6,900 - 7;800 kPa (70 - 80 kgflcm' ,
1,000 - 1.140 psi), A low reading means pump out-
Dut is too low for {ull assist. Repair or replace the
oumo.
17-17
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