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Power Steering Pump Replacement


With the reservoir now removed from the pump body, Mike and I opened up the plastic box that held the power steering pump pulley puller.  No instructions were in it but it wasn't that difficult to figure out.  The pulley has a collar right where it fits over the pump shaft.  The puller engages this collar and a large bolt, as shown in the above picture, pushes against the pump shaft which pulls the pulley off of the shaft.  Here is a more detailed explanation of using the pulley remover.


As seen in the above photo, one holds a nut in place while screwing the bolt into it which pushes the shaft out of the pulley's hub.  I was surprised when I realized that the pulley is held onto the pump shaft with just a friction fit.  The paperwork that came with the pump said it is possible that your pulley can be stretched and so will not reliably fit on the shaft when you assemble it on the new pump.  Although not shown in the above picture, we used my cheapo 12V electric impact wrench to initially get the pulley broken loose..  Mike had never seen me used it but it did the job sufficiently and we were able to break the pulley loose after 45 seconds of the little impact wrench smacking the daylights out of that big bolt.  We finished up pushing the pump shaft out of the pulley with a ratchet.  Once it gets started, it goes pretty good.  It would NOT have been a fun job trying to get it broken loose had it not been for the impact wrench.  Holding that pulley while putting the lean on that socket, even with a big breaker bar, would have been difficult.


The new pump came with a bolt, nut, and washer that together made up the power steering pump pulley installer tool.  It is pretty straight forward.  The pump shaft has a tapped hole in it that the bolt, as shown above, is threaded in to.  By holding the head of the bolt and tightening the nut, the nut and washer force the pulley down onto the pump shaft.  You simply tighten the nut until it stops, at which time the pulley has been seated flush onto the pump shaft.  This is the step were you would notice if you had a stretched pulley as it would slide onto the shaft very easily (or it would simply be a sloppy fit).


At this point, you basically reverse the steps you took while removing the pump.  Carefully seat the reservoir into the pump body and reattach the two metal clips that hold these two pieces together.  Mount the pump body to the bracket using the three bolts.  Route the serpentine belt around the pump pulley and adjust the belt tension.  Don't forget to tighten the bolt in the middle of the tensioner pulley when you are done with this step.  Install the high pressure line at the pump body.  Note that your pump may come with replacement o-rings (very small) that fit on the high pressure pump fitting.  As I was going to use a different high pressure line, I didn't need the o-rings but if you are simply doing a pump replacement without any other changes, follow the pump manufacturers directions concerning the replacement of the o-rings, assuming they supply them. 


My pump came with a filter.  I've never seen a power steering pump filter before but as you can see in the above picture, there it is.  Although mentioned in my pump literature, I believe the Hydroboost vendor was responsible for including it in the kit.  Regardless, it sure seems like a good idea and would certainly be a no brainer if you actually had a pump failure and there was a chance of having contaminates (metal filings, etc.) in the system.  Disregard the hoses in the above picture as it is part of the Hydroboost hoses that are supplied with the system.  The filter is installed in the low pressure return line.  Just note the direction of the fluid flow and match the big arrow on the filter to the fluid flow.

With the filter installed and the remaining hose clamps tightened, it was time to bleed the air from the power steering system.  I'll confess that the addition of the Hydroboost and several extra feet of hose introduced a significant amount of trapped air in my system.  A regular pump replacement should not cause quite as much air in the system, but you will have some.

The literature that came with my power steering pump included steps for bleeding the system.  Assuming your replacement pump does too, I would recommend you follow them.  If all you got in your pump's shipping box was the pump, you will probably do just fine if you follow the method I used.

Fill the reservoir with the vehicle manufacturer's recommended power steering fluid and let it set UNDISTURBED for a few minutes while you recheck your work (hose fittings, clamps, mounting bolts, etc.)  Wipe down the pump body, reservoir, and fittings so that any fluid leak can be easily detected.  I filled the reservoir to within about 3/4" of the top, which was just about right.  While bleeding mine, there were several times when the fluid would rise and fall within the reservoir and had it been fuller, it would have bubbled out of the top and contributed to the mess I was trying to avoid.

Raise the front of the vehicle and support the axle (small jack stands are perfect for this) so that the tires miss touching the ground.  WITHOUT STARTING THE ENGINE, slowly begin to cycle the steering wheel.  The word SLOWLY is important....it means about 1 revolution of the wheel every 8~10 seconds.  Continue to add fluid to the reservoir as necessary.  While Mike and I slowly worked the steering wheel back and forth, the fluid level would rise and fall and then we would have to add some more.  Finally, the fluid level barely changed as we turned the wheel from stop to stop and it seemed as though we had gotten the bulk of the air out of the system. 

We looked for any signs of leaks and finding none, we started the engine.  There was a little bit of growling from the power steering system but it was not that noticeable (I've heard worse in Jeeps that were out on the trail).  With the engine at about 1200 RPM, slowly cycle the steering wheel in both direction, lightly contacting the wheel stops.  Continue to check fluid level and add if necessary.  Note that there are fill marks on the reservoir cap's dip stick.  If the pump begins to get noisy, turn the engine off and let the system set for about 15 minutes.  Air in the system will cause the pump to groan and the fluid level will rise when the engine is turned off.  Lots of tiny bubbles in the reservoir is a good sign of trapped air in the system.  Repeat the above steps until your power steering is operating normally.

My newly installed power steering pump was pretty much bled free of air on the first attempt.  We turned off the engine one time and let it sit for a bit, then slowly cycled the steering wheel and added a bit of fluid.  The 2nd time we started the engine, the pump sounded fine, no whining, and no bubbles in the fluid.  Remove the jack stands from the front axle and take it for a test drive. 

That's it!  If all went according to plan, you are now the proud owner of a newly installed power steering pump...and you saved yourself significant bucks by doing it yourself!  And the best part is that you did the work yourself and that you know it was done correctly. 


Mike and I ran out of time when we were doing the Hydroboost install.  It was, and still is, my intention to install a small automatic transmission cooler in the low pressure return line coming out of the steering gear box.  As I mentioned before, heat and power steering fluid does not play well together.  I plan on giving my newly installed pump the best chance I can towards a long and productive life.  You should find a write-up covering the above cooler install fairly soon.

Good wrenchin' and remember to TREAD Lightly!



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