What is the pressure specs for a GM Type 2 power steering pump?
In general, GM Type 2 power steering pumps deliver high-pressure fluid on the order of 1,000 to 1,500 psi to the steering rack, with the system’s relief valve typically set around 1,500 psi to prevent over-pressurization. Exact figures vary by vehicle and variant, so always refer to the factory service manual for your specific model.
Understanding the Type 2 pump and its pressure control
The Type 2 power steering pump is a common GM design used on a range of cars and light trucks. It circulates fluid from a reservoir into the high-pressure circuit that assists steering. A relief valve within or near the pump regulates the maximum pressure to protect the rack, hoses, and seals. The low-pressure side draws fluid from the reservoir back into the pump, creating a continuous loop that provides assist as the driver turns the wheel.
Typical high-pressure ranges
Here are the commonly observed pressure ranges for the high-pressure side and the relief setting, noting that actual values vary by vehicle year and hardware (rack, hoses, and power steering gear):
- Normal operating high-side pressure: approximately 1,000–1,500 psi (69–103 bar).
- Peak pressure under heavy steering or near full lock: up to about 1,500–1,800 psi (103–124 bar) in some installations.
- Relief valve setting (maximum system pressure): generally around 1,500 psi (about 103 bar); some variants may be set as high as 1,700–1,800 psi.
Because GM used several sub-variants of the Type 2 pump across different models—from cars to trucks—the exact relief setting and operating pressure can differ. Always consult the factory service manual or GM's official specs for your specific vehicle to confirm the numbers before service or testing.
How to verify the pressure with the right tools
To measure the Type 2 high-pressure output, use a compatible power steering pressure tester and connect it to the high-pressure line or a test port appropriate for your vehicle. The following steps outline a typical procedure, done with proper safety and at the correct engine idling conditions:
- Attach a gauge designed for power steering systems to the high-pressure port, or use a temporary adapter that fits the system’s high-pressure line.
- With the engine running and the wheel unlocked, slowly turn the steering wheel from lock to lock on both directions to raise pressure and observe peak readings.
- Compare readings to the vehicle’s service manual expected range; readings significantly above the expected maximum may indicate a faulty relief valve or a problem in the steering rack or hoses.
Accurate testing requires following safety protocols and factory guidelines; incorrect readings can mask a failed component or create hazardous conditions while diagnosing the system.
Summary
The GM Type 2 power steering pump typically produces high-pressure readings in the 1,000–1,500 psi range, with relief valve settings commonly near 1,500 psi. Exact numbers vary by model and year, so always verify against the specific vehicle’s service documentation. Proper testing with the right tools and adherence to safety standards is essential to diagnosing pressure-related issues in the power steering system.
