Vehicle loses steering control without any warning

Hi,

When you say steering loss, do you mean you lose power assist? Also, when it veers, are you applying the brakes or is there anything that you noticed? Have the steering components such as tie rods, ball joints and so on been checked? Has anyone checked to make sure the steering gear is tight?

I attached a pic of the gear below and highlighted the bolts which secure it to the frame. Have a helper get in the vehicle and move the steering wheel from left to right as you watch the gear to make sure it isn't moving.

Let me know what you find.

Joe

Hi,

The only way that could happen would have been if the steering wheel was disconnected from the steering components/gear. Otherwise, you would have had some control when turning unless the steering wheel locked, preventing you from turning it.

Do me a favor. Try what I said. Have a helper turn the wheel while you watch to see if the steering gear is moving loosely. If you open the hood, follow the steering shaft from the firewall and it will lead to the gear.

Joe

Hi,

The items you mentioned wouldn't cause a steering loss. Tell me, could the power assist have simply become extremely strong causing the steering to feel so easy to turn it seemed control was lost? There is an internal pressure valve in the pump that can fail.

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Here are the test procedures for pressure:

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2000 Isuzu Truck Trooper LS V6-3.5L
Power Steering Pressure Test
Vehicle Steering and Suspension Steering Testing and Inspection Component Tests and General Diagnostics Power Steering Pressure Test
POWER STEERING PRESSURE TEST
PROCEDURE

pic 1

Test of fluid pressure in the power steering system is performed to determine whether or not the oil pump and power steering unit are functioning normally.
The power steering system test is the method used to identify and isolate hydraulic circuit difficulties. Prior to performing this test, the following inspections and corrections, if necessary, must be made.
- Inspect pump reservoir for proper fluid level.
- Inspect pump belt for proper tension.
- Inspect pump driver pulley condition.
1. Place a container under the pump to catch the fluid when disconnecting or connecting the hoses.
2. With the engine NOT running, disconnect the pressure hose at the power steering pump and install power steering tester J-29877-A. The gauge must be between the shutoff valve and pump. Open the shutoff valve.
3. Check the fluid level. Fill the reservoir with power steering fluid, to the "Full" mark. Start the engine, then turn the steering wheel and momentarily hold it against a stop (right or left). Turn the engine off and check the connections at tester for leakage.
4. Bleed the system.

5. Start the engine and check the pump fluid level. Add power steering fluid if required. When the engine is at normal operating temperature, increase engine speed to 1500 rpm.

CAUTION: Do not leave shutoff valve fully closed for more than 5 seconds, as the pump could become damaged internally.

6. Fully close the shutoff valve. Record the highest pressures.
- If the pressure recorded is within 9300 - 9800 kPa (1350 - 1420 psi), the pump is functioning within its specifications.
- If the pressure recorded is higher than 9800 kPa (1420 psi), the valve in the pump is defective.
- If the pressure recorded is lower than 9300 kPa (1350 psi), the valve or the rotating group in the pump is defective.
7. If the pump pressures are within specifications, leave the valve open and turn (or have someone else turn) the steering wheel fully in both directions. Record the highest pressures and compare with the maximum pump pressure recorded in step 6. If this pressure cannot be built in either side of the power steering gear, the gear is leaking internally and must be disassembled and repaired.
8. Shut the engine off, remove the testing gauge.
9. Reconnect the pressure hose, check the fluid level and make the needed repairs.
10. If the problem still exists, the steering and front suspension must be thoroughly examined.

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I have a feeling the pressure went too high and the steering became so easy to turn, it felt disconnected.

Let me know.
Joe