Change 1 2-469
Check hydraulic hoses, power steering pump, power steering cooler, hydraulic control valve, hydro-boost unit, steering gear,
fan shroud, and fan clutch. See hose replacement procedures (refer to para 8-25). Check power steering cooler for bent fins
or any other airflow restrictions. Straighten fins or replace power steering cooler (para. 8-28) if damaged beyond repair.
If you have a power steering analyzer, you can use it here to test the power steering pump
and gear and the rest of the hydraulic system. If you use a power steering analyzer, you
don't have to follow the test chain further.
Refer to the Diagnostic Connector Assembly (DCA) Functional Flow Diagram (FO-16) for
DCA to Transducer Kit (TK) cross reference when using the STE/ICE-R.
You must be certain that the engine cooling system is working ok, or this test won't tell you
anything. If the engine is cold, and everything is working ok, the fan should be disengaged.
You can tell by gently revving the engine in neutral with the hood open. If the fan is engaged
you will feel a breeze outside the driver's door. If it's disengaged, you won't feel it. If you
aren't sure if it's working ok, run the tests in Paragraph 2-25.
Power steering analyzer procedure
1. Disconnect high pressure hose from hydro-boost leading to power steering pump. Connect analyzer to hydro-boost
and pressure hose. Open valve on analyzer.
1.1. Remove oil cooler and hydraulic control valve from hydraulic circuit by running a 54 in. (137 cm) piece of power steering
pump return line from gear return tube straight to pump return tube. Plug the disconnected hoses to prevent air from
2. Disconnect harness connector at hydraulic control valve (para. 8-26). Check fluid level in power steering pump and add
fluid as necessary.
3. Connect STE/ICE-R for purpose of recording engine rpm in step 8.
4. Start engine and allow it to idle for 3-5 minutes or until system is hot. Check for leaks.
5. Record pump pressure and flow rate. Pressure should be 220-250 psi (1,516-1,724 kPa) and a minimum of 3.0 -
3.25 gpm (11.35 - 12.3 Lpm) flow. If pressure is too high and/or flow is too low, check for restrictions in pressure lines by
passing air through them. Remove pressure relief cartridge (para. 8-30), clean the screen and bore of relief valve with
compressed air and drycleaning solvent. Check pressure and flow again. If readings are not within specifications,
replace power steering pump (para. 8-24).
6. Partially close valve on analyzer to increase pressure to 700 psi (4,826 kPa) and record flow. Subtract flow rate from
measurement in step 5.If flow varies by more than 1 gpm (3.8 Lpm), replace power steering pump (para. 8-24).
Do not leave valve fully closed for more than 5 seconds or pump damage will result.
7. Close and partially open valve on analyzer three times. Record highest pressure reading each time. All three readings
must be 1,300 psi (8,964 kPa) or above. If not, replace power steering pump (para. 8-24).
8. Open valve on analyzer and increase engine speed to 1,500 rpm. Record flow and compare to measurement in step 6.
If flow varies by more than 1 gpm (3.8 Lpm), remove pressure relief cartridge (para. 8-30), clean bore and screen with
compressed air and drycleaning solvent. Repeat step. If flow still varies by more then 1 gpm (3.8 Lpm) from
measurement in step 6, replace power steering pump (para. 8-24).
9. Turn steering wheel fully to the left and right and record flow at each stop. Flow should drop to 1 gpm (3.8 Lpm) or
less. If not, replace steering gear (para. 8-21).
10.Push brake pedal to floor and hold. Flow should drop to 0.5-1.5 gpm (1.9-5.7 Lpm) or less. If not, replace
hydro-boost (para. 7-14).
11.Turn steering wheel slightly to left or right and release quickly while watching pressure gauge. Pressure gauge
should snap back quickly. If pressure gauge returns slowly, replace steering gear (para. 8-21).
12.Push brake pedal down and release quickly while watching pressure gauge. Pressure gauge should snap back quickly. If
not, replace hydro-boost (para. 7-14).
13.When testing is done, connect harness connector to hydraulic control valve. Remove power steering analyzer,
connect steering lines, and bleed power steering system (para. 8-29).