A power steering system pressure test is primarily performed by conducting a "dead head pressure test" to determine the maximum pressure the pump can produce.
Power steering systems rely on hydraulic pressure generated by a pump to assist steering. When issues arise, such as stiffness, noise, or leaks, measuring the system's pressure can help pinpoint the source of the problem. One crucial test involves checking the pump's capability under maximum load.
Understanding the Dead Head Pressure Test
As highlighted in the reference, the first type of pressure test performed is typically a dead head pressure test.
- What it measures: This test specifically measures the maximum pressure the power steering pump is capable of producing.
- Purpose: By measuring the maximum output pressure, technicians can assess if the pump is generating sufficient force to operate the system correctly under demanding conditions. A pump that cannot reach the specified maximum pressure is likely worn or faulty.
Steps for Performing the Test (General Outline)
While the reference specifically mentions the dead head test and checking fluid, a typical pressure test procedure involves:
- Prepare the Vehicle: Ensure the vehicle is on a level surface and the engine is cool or at operating temperature, as specified by the service manual.
- Check Fluid Level: As noted in the reference, it's essential to recheck your fluid level both before and once done recheck your fluid level again after testing. Ensure the fluid is at the correct level and in good condition.
- Connect the Gauge: A specialized power steering pressure test gauge kit is connected into the high-pressure line, usually near the pump. This involves disconnecting a hose and installing adapters and the gauge.
- Perform the Dead Head Test:
- Start the engine.
- Momentarily restrict the flow in the high-pressure line (often by turning the steering wheel fully to one side, but only for a very short duration as this puts maximum load on the pump and can cause damage if held too long).
- Observe the pressure reading on the gauge while the flow is restricted. This is the dead head pressure.
- Compare to Specifications: Compare the measured dead head pressure to the manufacturer's specifications for the vehicle's power steering pump.
| Test Type | Measurement Goal | Key Finding |
|---|---|---|
| Dead Head Pressure | Maximum pump output pressure | Pump wear or failure |
Why is this Test Important?
- Diagnosing Pump Issues: A low dead head pressure reading directly indicates a weak or failing power steering pump.
- Identifying Restrictions: While the dead head test focuses on the pump, other pressure tests (not detailed in the provided reference snippet) can help identify restrictions in hoses, steering gear, or rack and pinion assemblies.
- Preventing Further Damage: Identifying a faulty pump early can prevent related issues caused by insufficient pressure.
Performing a pressure test, starting with the dead head test, is a critical diagnostic step for troubleshooting power steering problems. It requires proper tools and adherence to safety procedures, particularly regarding the duration of the dead head restriction.
