2nd gen 4.0L power steering pump rebuild

Rebuilt my power steering pump on my 4.0L 2nd gen this weekend and couldn't find a picture guide for it. Decided to take photos and put one together in case others wanted to give it a go. It was around $20 CAD for my rebuild kit and several hundred dollars for a new pump, so the cost savings were substantial for me. In the end it was a fairly simple job.

What you will need: rebuild kit, sockets, Dexron ATF, seal puller, torque wrench, possibly impact wrench.

Be sure to match up the O-rings from the rebuild and the pump correctly as you swap them. Some of the smaller ones are quite similar, but still different enough that it is important.

STEP 1: Remove the pressure port union sub assembly and the power steering oil pressure switch before removing pump from engine. If you don't remove these before taking it off the engine, don't fret. It's simple to take them off with an impact wrench by pinning the assembly down to a tabletop, just don't ding anything important if you use a clamp to hold it. Uninstallation is simple and messy. Won't include a guide for it here. Note: when you remove the pressure port union sub assembly you will likely get a spring and the flow control valve coming out at you. If so, clean them, put a bit of ATF on them, and put them back into the assemble before putting the pump itself back in. I've included a photo of how they go back. Replace the O rings on both the pressure port and the pressure switch.




STEP 2: Clean the pump off. I used de-greaser but there are certainly many different methods.

STEP 3: Undo the housing bolts on the rear of the pump.


STEP 4: Pull the rear of the housing off and observe the largest O-ring you will need to replace. Remove the O-ring, clean the housing well. Replace the O-ring. Place housing + O ring in a plastic bag to keep clean.


STEP 5: Remove the retention clip from the pulley shaft and then slide the pulley out from the rest of the assembly.


STEP 6: Remove the vane pump cam ring (elliptical shaped metal piece), vane pump rotor (metal circle with the slots in it) and the vane plates (there should be 10 of them) and gently clean them. Place these parts into a bag to keep clean.


STEP 7: Remove the vane pump side plate front (the other metal piece left in the housing) and observe 2 more O-rings that you will need to replace. 1 is smaller and in the center of the plate, the 2nd is larger and site on the outer portion of the plate but may also be left in the front housing. This is how mine looked on disassembly.


STEP 8: You should now have the vane pump housing front laying in front of you. Flip it over so that the outside portion is facing up. You will see that there is a seal where the pulley shaft enters the assembly. This can be taken out using a seal puller. Be careful not to ding the metal surrounding the seal with the puller. Mine came out fairly easily, hopefully yours does too. Clean the housing after removal.


STEP 9: Now you will start putting things back together. Take the new seal from your kit and use some ATF to lubricate the outside of it where it will be wedged into the housing. Also put ATF on the housing side. You can slide the seal in a couple of millimeters with your fingers. The next step varies depending on your nationality. If you are Canadian, take a hockey puck and use it to drive the seal in the rest of the way, which is until it is flush with the housing. Anywhere else in the world, a piece of 2x4 or similar will work.


STEP 10: From this point on ensure all O rings have been replaced! Take the rear housing and lay the outside facing portion down. Then grab the vane pump cam ring and line it up with the rear housing as shown below. note that the depression in the cam ring fits onto the shaft on the housing, and that the capital N seen on the housing and ring are mirror images that will touch/kiss in the assembly.


STEP 11: Take your cleaned vane rotor and vane plates, apply a film of ATF, and reassemble them. Then place them into the cam ring.


STEP 12: Take the vane pump side plate and put it on top of the vane cam and rotor assembly. Note that it has a depression for the shaft extending from the rear housing. You will note in my photo that the larger O ring for the vane side plate is not present. I had left mine in the front housing during this photo, but in restrospect it would be best to have it in position on the plate here. I did not get a photo of that, but hopefully you know what I mean.


STEP 13: Take the cleaned front housing and again put a film of ATF in it. Place it over the assembly you have made consisting of the rear plate, rotor assembly, and side plate. Sandwich the 2 parts together.


STEP 14: Put some ATF on the inner portion of the shaft seal, and then grab the shaft/pulley assembly and put ATF on the shaft. Put the shaft, carefully so as not to damage the seal, through the seal. You may have to lift and slightly rotate the assembly a couple of times so that the teeth on the shaft line up with the vane rotor. Once you have slid it in all the way, firmly hold the assembly together and flip it over.


STEP 15: Remove the back plate and expose the assembly with the pulley shaft sticking out the end. You will need to install the new snap ring, from your kit, on the shaft. I ended up using a couple of flat head screwdrivers to open it and put it down onto the groove it must sit on.


STEP 16: Replace the back plate and torque the bolts on the rear plate. They will be torqued to 16ft lb. While you are at it torque the power steering oil pressure switch to 15 ft lb and the pressure port union sub-assembly to 51 ft lb (or wait til it is reinstalled as it may be difficult to achieve this torque at this point).

STEP 17: Reinstall the pump onto the engine, torquing the installation bolts to 15 ft lb. Replace the O-ring on the power steering suction port union as your kit likely came with it. The suction port is torqued to 9 ft lbs. You may also notice a washer for the pressure feed tube assembly, this assembly is torqued to 38 ft lb, and there may also be a teflon washer which I assume is for the rack? If you know what it's for let me know because haven't touched the rack and have not come across it anywhere else in the power steering assembly.



After reinstallation of the pump and reconnection of the tubing, you will need to refill your reservoir with the dexron ATF. As suggested by forum user @shaeff You'll then want to raise the front end of the truck off the ground so that the front wheels are not in contact with the ground. Do this safely, of course, using proper technique to prevent injury. With the wheels off the ground and the vehicle off, you will want to turn the wheel all the way side to side, lock to lock, to work the ATF through the system. If your wheel locks you may need to insert your key and turn it forward, without starting the vehicle, to unlock it. You will want to watch the fluid level in the reservoir during this procedure as it is likely you will need to add more. I continued to watch my level for the next couple of days after completion.

Hopefully this write up is helpful to someone in the future. I'll have to come back to edit it later if there are mistakes.

 

What's the part number for the rebuild kit?

 

I used the AC delco one off rockauto.

The number was 36348379.

It is still going strong at this point with no leaks.

 

Thanks! I actually found it OEM but great write up! Will follow it and hopefully will not have to buy a new pump

 

One thing I should add is that when starting up for the first time with the new pump there was a bit of a whine which went away after turning the steering wheel all the way back and forth a few times. I made sure to keep the fluid level at the fill line throughout that part of the procedure.

Good luck with it!

 

Yeah that's expected as the air bleeds from the system, and thanks!

 

Best to jack the front wheels off the ground, truck OFF, work the wheel back and forth lock to lock a bunch of times. It’ll pull fluid through the whole system. No whining, no aeration of the atf, no whining.

Did it this way a few weeks ago when I replaced my rack and it worked great. Read it on this forum.

 

That’s what I always do, works great.

 

@tcBob can we add this to:
2nd Gen Tips, Mods & More

 

This write-up is mint! I’m gonna save this.

 

Nice write up rapidmoleman. Curious what symptoms you had for the rebuild ? My trucks power steering is bery stiff and over about 8 mph wont return to center.

 

Just went to do this on my truck because I had no power steering below 2k RPM and above the pump whined loudly.

My pump doesn’t appear to be OEM it looks different than @RabidMoleMan ’s

My oil flow control valve didn’t come out on it’s own, I had to pull it and then pull the compression spring also. I thought hmm. Strange. So measured the spring and it’s free length was only 31mm, per FSM it should be 36.5mm at minimum. FSM tells you to replace pump assembly in that case. Seems fucked to me so does anyone have a clue where to source a replacement spring?

 

Sorry I haven't responded. Been away from the forum for a while.

@shaeff Thanks for the info per lifting the front end and leaving the truck off prior to working the ATF through. Certainly sounds safer and I'll certainly recommend this method vs what I did. Luckily I had no issues and the power steering on mine has been great with no loss of fluid or other issues since. I'll change this part in the procedure with credit to you.

@APACHETECH The signs I saw which led me to do the rebuild were major leaking at the vane pump assembly. It was impossible to pinpoint where the fluid was coming from, but multiple seals were likely culprits. Other than that I didn't experience much in the way of symptoms. No stiffness and no whining as I made sure to keep up on the refills as I lost fluid.

@hx989 Sorry to hear about the issues. After reading your comment I worried that perhaps I had missed there being a change in the part number, for the vane pump, given the differences you've seen in your pump. I went through the parts diagrams for each year of the 2nd gen Tacomas and it appears to be the same every year. Not sure if you've had luck in your search for the spring and given it is almost 1 month later I feel bad for not having seen this earlier... I believe, can't guarantee 100% though, that the part number is 90080-50222 and it can be had from toyotapartsdeal.com or a few other sources for a very reasonable price.

 

Did you do a flush while you did the rebuild?

If so, what method did you use?

Add an in-line filter as well?

 

I did not do a complete flush during the rebuild though it would have been a good idea. I figured I had lost and replaced so much due to leakage that I was probably OK without it. I did not add an in line filter. Sorry for my lack of help there!

 

Sorry for digging up an old thread RabidMoleMan. I found your post when I was looking for info on the 1GRFE in my Prado. Great step by step. Did you notice any movement/end float in the pulley shaft before and after the rebuild. I've got 1mm of movement in/out, no wobble. From your photos it looks like its just the circlip that stops the shaft coming out and i couldn't see any bearings?

 

@tcBob
This thread should be elevated to sticky status IMHO.
Reasons being the OEM 2nd gen PS pump has now been discontinued.
And it is a super write-up.
Did a quick and did not see it on the lists, sorry if I missed.

 

I just rebuilt mine using this as reference. Spot on thanks! Mine had a weeping input seal, and I ended up using the OEM seal kit ($60 CDN).

 

Ordered the kit and spring from my dealer. Waiting on order status update to pick it up.. Let's hope I don't need that steering rack bolt.

Power Steering Pump Seal Kit 0444602140 $19.89

SPRING, COMPRESSION(FOR FLOW CONTROL VALVE) 9008050222 $0.87

BOLT, WITH WASHER 90119A0135 $4.56