Diagnosing a power steering pump leak isn't difficult. The challenge comes from determining whether the leak is from the actual pump, one of the hoses, one of the seals that attach the hoses to the pump, or one of the other areas to which the power steering fluid flows. There are specially formulated power steering fluids that help seal leak; however, solution often hides the problem rather than fixing it. If the power steering pump fails while you are driving, it would make steering very difficult, if not impossible. Toyota vehicles label the power steering cylinders for easy maintenance.
Start the vehicle with the hood up. Have a friend turn the steering wheel to the left and right as you inspect the area around the power steering pump. Look at the seals that secure the hoses to the power steering pump. Often leaks will form where hoses are connected or where a hose has rotted or split. Put a drip pan underneath the pump to catch any fluid that leaks.
Rub a clean, dry rag or your finger over these connection areas. If there is power steering fluid in this area, then the issue is with the seals and hoses, not the pump.
Inspect the pump. Look closely—but safely—for cracks or fluid spewing out when the wheel is turned fully to the left or right. If the pump is the source of the leak, Toyota recommends changing the pump and changing the seals and hoses at the same time you replace the pump.
Purchase the correct power steering pump for your Toyota. Consult a Chilton's Repair manual to find the correct pump for your model and year Toyota. Different models and years use different sized pumps.
Remove the negative battery cable from the terminal. Remove the high-pressure line from the pump with a wrench and then from the gear side of the pump. Remove the low-pressure line by moving the hose clamp. Depending on which model Toyota you are working on, the hose clamp will either be a clip style that can be removed by hand or will require a screwdriver to do so.
Remove the old pump by removing the bolts that secure it to the vehicle. You have the option of replacing the belt and pulley system as well as the pump. That may not be necessary. Check the belt for cracks or wear and if need be, consult a Toyota mechanic to inspect both.
Bolt the new pump on and attach the new high and low pressure hoses and clamps. Fill the power steering pump with power steering fluid and start the vehicle. Have your friend or partner turn the wheel as far to the left and right as they can to let the power steering fluid fill the hoses and bleed the air from the hoses and pump housing. Secure both hoses to the pump and to the gears with the new clamps. Tighten these clamps to prevent leaks around the edges.
Refill the pump using the fill reservoir and take a drive. Make several turns and when safe, make a few 360 degree turns.
Park the vehicle and check the power steering reservoir. If there is no change in level, the leak has been fixed. If there is foam at the top of the reservoir, air is getting into the system. There could be an issue with the rack and pinion or the pulley and gear system.
