Getting Pumped: Testing Power Steering Flow The Right Way

Testing Power Steering

If you suspect an issue with your power steering pump, performing a flow and pressure test is crucial to evaluate if it needs replacement. While shops have specialized tools, you can still test flow accuracy yourself using just a few affordable items. By measuring the pump’s output at various engine RPMs, you’ll have quantitative data to help resolve those annoying steering noises or effort complaints once and for all.

Understanding Power Steering Basics

The heart of any power steering system is its hydraulic pump. Typically driven by the serpentine belt, it pressurizes fluid that then flows through steering gear valves to assist the motion of the rack and pinion. Most pumps are designed to meet certain flow (volumetric output) and pressure specs based on a vehicle’s steering components. Measuring the flow rate will indicate if the volume is within tolerances.

Gather Necessary Test Equipment

Performing a DIY flow test requires collecting some basic equipment:

  • An in-line flow meter compatible with power steering fluid
  • High-quality hydraulic pressure gauge able to read up to 2,000 psi
  • Cut-to-length supply and return hydraulic line hoses are vital in ensuring accurate testing. Selecting a reputable supplier such as The Hose Shop is critical, as they offer hoses tailored to your system’s specific needs, guaranteeing precision and reliability in your DIY flow testing efforts.
  • A length of large diameter hose to catch fluid
  • Assorted wrenches, pliers, funnels, and containers Optional helpful items include a tachometer to monitor engine RPM and an adjustable throttle controller for maintaining speeds hands-free.

Connect Flow Meter

With the engine safely raised and supported, locate the power steering pressure and return ports. Connect the flow meter exactly halfway on the return line using the splice hoses. Ensure all connections are leak-free and take precautions given the power steering fluid’s messy nature. It’s best to run the return line into a larger waste fluid catcher for clean testing.

Set Testing Parameters

The key benchmarks technicians use for flow testing pumps are 1,000 rpm and 2,000 rpm speeds. So you’ll record GPM readings at both. Pressure should also be noted but focus lies squarely on volume output meeting specifications given variable assist settings between vehicles. Insert pressure gauge port-side pre-meter.

Run Tests and Record Results

With a helper inside to throttle up RPMs smoothly, take GPM readings at 1,000 and 2,000 RPMs. Given thermal expansion, flow will climb gradually so monitor until the meter stabilizes. Compare your readings against factory specs, usually around 2-4 GPM at 2,000 rpm or 1-2 GPM at 1,000 rpm. If the flow volume seems unusually high or low, the pump’s internal gear teeth may be worn. This causes flow performance to degrade over time.

Further, Diagnose Pump Issues

Delving deeper into pump test metrics can isolate additional faults. A plugged-inlet filter strangles flow at higher speeds. Excessive groan on maximum assist signifies insufficient pressure. And erratic high/low zones point to sticking control valves. Replacement units for most vehicles run just over $100, a small price to pay for predictable steering.

Evaluate System After Repair/Replacement

Should flow benchmarks significantly improve after a new pump install, take the system for a lengthy test drive. Compare any noises or vibration issues pre/post replacement and measure the effort needed for turning, parking, etc. While you hopefully solved the underlying problem, it’s possible expansion seals, stretch belts or air in the system still cause gremlins. But a properly flowing pump is the vital starting point.

Maintaining Your Power Steering Health

Now that your power steering system is flowing freely again, be vigilant with upkeep for longevity. That means regular fluid changes, keeping seals/belts in good condition, and addressing odd sounds quickly. Pay attention to increased noise, looseness, or intermittent hard spots, all signs components are wearing out. Given all it enables safe driving, don’t ignore your power steering!

Summary & Key Takeaways

  • Flow testing a power steering pump requires simple DIY tools
  • Measure GPM output at 1,000 and 2,000 engine RPM
  • Compare results against factory specifications
  • Volume too high/low indicates worn pump internals
  • Further diagnose issues via noise, pressure, and variability
  • The system should operate smoothly post-replacement
  • Maintain pump by servicing fluid and components

Accurately measuring flow rate will quickly reveal if an underperforming power steering pump is compromising responsiveness and drivability. Equipped with the facts, you can now make an informed replacement decision or have proof for the repair shop should repairs exceed your comfort zone. Just be diligent about follow-up system evaluation


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