Changing P/S hoses on an ’04 WRX

[Lorrin Barth]

The power steering hoses come as an assembled kit. You will also need two o-rings for the fittings at the rack (these are tiny and one is larger than the other) and a metal seal for the banjo fitting at the pump.

Remove the undercover and raise the car using the lifting plate on the centerline behind the engine and place on stands. Once on stands remove the lift plate. Drain the radiator. This doesn’t need to be completely drained, just enough to empty the top of the engine.

Remove the accessory drive belt guard. Unplug the air sensor. Remove the upper half of the air box and the air filter. Remove the hose between the air box and the elbow that goes under the intake manifold.

Remove the three hose connections on top of the antifreeze tank on top of the engine. Then remove the two bolts and the one nut mounting the tank. You will then find a forth hose that connects to the underside of the tank. Remove this and remove the tank.

Looking along the side of the engine you will find two brackets that bolt the hoses to the engine. One has two fasteners and the other has one. Remove these. The hoses should now be free from the engine except at where they attach to the return hose at the reservoir and the pressure hose where it attaches to the pump.

The hose attachment points underneath are in an awkward spot. I chose to pull the axle in order to have room to swing a wrench. Maybe you have some magic tools in your toolbox making this unnecessary. The SM says nothing about doing this.

With the axle out the fittings on my car came loose with very little effort. Have a drain pan ready to catch the fluid.

On top, disconnect the return line from the hose on the reservoir. Then place plastic over the power steering pump pulley and remove the banjo bolt. On my car the fitting under the banjo wanted to unscrew along with the banjo bolt. Watch if this wants to occur and if necessary, hold it with a wrench. I had let the lines drain overnight so when I disconnected these upper lines there was no spillage.

Remove the hose assembly.

Notice, there is a bracket near the lower end of the old hose assembly. It has an “8” marked on both sides. One half of the bracket is welded to a line but the other half is used on the new hose assembly and the “8’s” when the bracket is reassembled on the new hose have to be across from each other (on the same end of the bracket.

Now there are two was you can go here. I had a camera so I photographed the old hose assembly from several angles before I removed the bracket. Then I was able to position the bracket such that it held the end fittings in the exact position as on the old assembly. The other way is to attach the lower fittings and then attach the bracket. This is the SM way of doing this but the bracket lives in an awkward to reach spot. I chose the first method and it worked very well.

Next remove the old o-rings from the pipes on the rack and thoroughly clean where the new o-rings go and replace with new. These o-ring are tiny and very easy to lose so use the up most care when installing. Be super careful. Next feed the new assembly through and attach at the lower fittings. The correct torque is only 11 ft lbs. Going much beyond this will probably trash the o-rings. Also check while underneath that the hoses or lines are at least 3/8 inches away from the body or the engine. Bend the lines a little to get the necessary clearance if necessary.

Attach the pressure hose to the pump using a new metal seal. Tightening torque is 29 ft lbs.

The rest is just replacing what you took apart. Pour the amount of new Dextron III into the reservoir that matches the amount that drained. Failure to do this can cause near instant failure of the pump. Also, top up the coolant. Start the engine while the vehicle is still on stands and turn the steering lock to lock a few times to remove air in the system. Check the power steering level in the reservoir. Top up or remove fluid as necessary. Check for leaks.

Replace the lift plate but leave the undercover off for a few days so you can continue to check for leaks.

Topic