First, let’s talk about a failing power steering cooler. Power steering pumps serve a very specific function. They are designed to move hydraulic fluid through the power steering system which in turn aids the turning of the wheels. It aids the turning of the wheels by utilizing the hydraulic pressure it creates to assist in pushing the pinion gear assembly to the side the driver designates by turning the wheel one direction or the other. Most of the time a power steering pump fails and does not include an external leak, it will result in stiff steering. This stiff steering will be felt in both directions, not just to one side. And while increased steering effort will still be required, it may subside slightly with increased vehicle speed.

This symptom can be a sign of internal failure of the power steering pump and a sign the pump is not moving as much fluid as it is designed too. It is strongly recommended you use a power steering pressure tester to verify that the fluid is not being moved to optimal pressure by the pump. This same symptom can also be a sign of a clogged power steering line or power steering cooler. If you do have internal failure of a power steering pump, it is strongly recommended that you replace all power steering components at that time to avoid any contamination of a new part with the metal shavings from the failed power steering pump. At a minimum, the system must be flushed thoroughly in order to remove any residual contaminants from the system.

A rack and pinion that fails will often have very specific symptoms. Most of the time external leaks can be found on rack and pinions by closely examining all vent tubes, pressure and return ports, and the inner tie rod boots. If you suspect your rack and pinion is leaking into the inner tie rod boots, poke a small hole in the boot closer to the rack and pinion assembly. If any fluid comes out it should indicate the external seals are leaking. Any leak point that is allowing fluid out is also allowing air in, and the power steering system is not designed to handle any air. The boots on the rack and pinion are purely just dust covers and should not hold any fluid.

If your vehicle has stiff steering at only certain points while turning the wheel, this can be an indication that the teeth on the pinion gear are worn out and causing your issue. This same problem however can also indicate the universal joint on the intermediate shaft could be binding. Sometimes by spraying the universal joint on the intermediate shaft with a lubricant and moving it back and forth a few times will alleviate the stiff steering issue. If you lubricate the universal joint and your problem goes away, your issue is not your rack and pinion, but instead you need to replace the vehicles intermediate steering shaft. If after lubricating the shaft the problem is still present, the issue is your rack and pinion assembly. If you must replace your rack and pinion assembly due to an internal failure, it is strongly recommended that you replace all power steering components at that time. If for any reason you cannot replace all components at a minimum, you should flush the power steering fluid system thoroughly.