Diagnosing power steering pump failure la gas prices map


Power steering failures are definitely not any fun. In our forums, scsalin had a problem with his 2003 Hummer H2’s power steering going out completely. It was a sudden failure, which is a sign that it is most likely a p/s pump failure. This cannot be taken for granted, however, and with a replacement pump often having a price tag of a few hundred dollars, it is necessary that the pump’s failure be absolute.

No matter the vehicle, be it scsalin’s H2 or a low-cost economy car, testing the power steering pump is the same. In the case of this Hummer, there were recalls, which mechanic Big Block 409 pointed out, and those should be addressed first. Often, recalls and technical service bulletins (TSBs) are overlooked by the home mechanic and should be checked. They can quite often be checked simply by calling a dealership with your model and VIN.

To begin with, draw some fluid from the p/s fluid reservoir (usually located directly atop the pump) and put it on glass or a neutral background (white is best), such as a counter top or workbench. If the fluid is not the common color of the proper replacement fluid type, usually a brownish, oil-like color. It looks very similar to common brake fluid and the two are closely related.

If the fluid is any other color – milky, very dark (nearly black), etc.) – you may have serious pump issues that need addressing. A qualified mechanic or shop with a test kit can diagnose that directly. Likely it’s a bad pump, but other issues may be happening as well, allowing contamination into the fluid. Some auto parts stores sell "dropper" test kits which can also help you get an idea of what’s going on with your p/s fluid.

Next, check the serpentine belt that powers the power steering pump to be sure it is of the right type and is at the right tension. Belts can stretch over time, making them loose. Check the belt for wear as well and replace it if need be. Start the vehicle’s engine and use a stethoscope to listen to the pump. Carefully (the engine is turning, after all), listen to the pump housing. You’re listening for grinding or pinging noises. There should only be a steady pumping or "woosh" sound from the fluids moving through the pump. Shut the engine off and disconnect the negative terminal on the battery.

Now remove the belt from the p/s pump pulley, even if it does not require replacement, so you can spin the pump’s pulley with your hand. How freely does it turn? Are there noises? Does the pulley visibly wobble when spinning? If it does not spin relatively freely or makes unusual noises, the pump is likely bad. If the pulley wobbles, it or the shaft to the pump are bent and one or both will need to be replaced.

Lastly, lift the car off the ground (at least the front end). Make sure it is safely secured on jack stands with blocks to prevent the wheels from rolling or fully lifted on a proper mechanic’s lift. With the engine off, insert the key and turn it to the "on" position, but do not start the engine. Turn the wheel back and forth as far as it will go several times. If it moves without the pump operating, your steering system is likely OK. Listen for and check for any unusual sounds or feelings in the steering while turning. This could indicate ground steering gears or loose connections. Address those if you find them.

All of these things should give you an indication of the p/s pump’s condition. Under normal conditions, a p/s pump will often last the life of the car. These pumps are simple machines that rarely break. They are built robustly, due to the pressures they work under, and are basically just rotating shafts with an internal wheel that pumps fluid and the basic design behind them has been in use for hundreds of years.