Pressure and Return line for power steering on Rack and Pinion

Hello

I will be chaning my steering rack this weekend. I bought a used OEM rack that had low miles to change my rack. The rack came from a manual transmission and I believe those use clutch fluid for the power steering. I have an Automatic. So before I install the the new to me rack, I would like to flush out any clutch fluid that may be left in the steering rack.

My questions are:

1. Would it be bad if I just installed it without flushing out any remaining clutch fluid.

2. Is it safe to use an air compressor to just pump air into the pressure line and force out any remaining fluid out the return line.

3. If it is bad to use air my other plan was to just sit there with a fluid pump to just pump fluid in the pressure line until it come out of the return line.

4. I want to say that the bottom line is the fluid pressure feed line and the top one is the return on the steering rack. Can someone please verify? I dont want to pump air or fluid in the wrong direction.

I have already bought energy suspension bushings to replace the old ones.

 

I don't know anything about the racks for manual tranny trucks being any different, I thought the racks were the same for auto or manual tranny trucks with the only difference that I knew about was 4wd and 2wd versions are different sizes.

so lets assume you are right and its a different system, well just because it looks the same and mounts the same doesn't mean anything so how did you decide if it would even work on your truck, being that it is a completely different system if what you say is correct?

 

All 4wd and Pre Runner 1st gen Tacomas use the same rack as do the 4runners of the same platform. After around 01 they have the upgraded guide.

They all use the same fluid, Dexron 2 or 3 ATF.

The lower line of the 2, up by the steering shaft connection is the pressure line.

I would flush out any used rack. Use a hand pump, squeeze bottle or what ever low pressure device is handy. Do not use an air line. Pump in the fluid while turning the control valve shaft thru it's entire range a few times, otherwise you will just be flushing out the control valve.

It's also a good practice to slide up the rubber umbrella shaped shield on the control valve shaft and clean or flush away any accumulated crud. It's a little counter intuitive, but that "shield" likes to trap dirt between itself and the seal it's protecting.

 

I believe they are the same rack. When I check on rack doctor they dont carry seperate racks for manual and automatic. only thing im mainly concern about is the different type of fluids used. previous owner said he ran clutch fluid in it and that I would just need to drain that and add ATF.

 

Thank you! Just the info I was looking for! Yes, that control valve dusk cap is wear my truck is leaking. I believe it is from dirt build up breaking the seals. I will use ATF DeX 2 or 3 to flush the rack with the handpump i use for chaning diff/trans fluid. Thank you very much. Seller told me to use an air compressor but I was thinking that may force stuff where it should be and mayeb break some seals. Thank you.

 

Make sure you don't lose the "union seats". They are replaceable conical "seats" in the control valve housing for the pressure/return lines. Sometimes they stay in place, sometimes they take a hike.

 

One more thing. Try turning the steering shaft a few times first to see what kind of fluid comes out. If it is brake fluid as is used in the clutch system, there might be problems, or not. I have never heard or read of someone using brake fluid in a Taco rack or the consequences. Flush that baby good.

 

I will make sure to not lose the unions. The rack came complete with the lines and tie rods. I saw brownish fluid come out. Not sure if it is Clutch or MTF. PO said the rack is in great working condition with no problems or leaks ever.

 

It pry wouldn't hurt to flush your pump and lines too, pry hasn't been done in a while if ever. You could mount up the rack then pull the return line off the pump, fill resevior and jack up front end then grab a tire(steering wheel un locked) and manually cycle the whole system by turning the wheel back and fourth. Might be easier than pumping just the rack clean and ya get a whole system flush.

 

I wonder if he might have used brake fluid to stop a seal leak? I cant think of any logical reason why the hell would he be using that in there?

just the fact it had something "funny" in it would make me look for another rack, I just wouldnt be able to trust it but im overly careful about used parts

 

^^^ yeah break fluid/dot3-4??? That's pretty weird!

 

Unprepared trail fix possibly,,You use and do whatever is necessary to get home or out.

Or laziness, on the previous owners part.

It is generally accepted that clutch fluid is brake fluid all the time,,and that's what was added as per the op's post. Not the last time you will hear of that one on TW.

A used OEM rack that specifically had clutch/brake fluid put thru it an unknown amount of supposedly low miles?,,You might be able to flush that out and get away with a few quick fixes. Worth a try,,even for the experience.

You definitely don't want that used rack to contaminate your system with brake fluid.

 

It was a local TW member so I trusted him. I should have done more research on the fluids before buying. Hopefully the rack is fine. I didnt see any oil marks on any of the parts and it didnt look like it was cleaned before I got there. Ill be flushing it thoroughly with the right fluid before the install and will contact the seller to double check on what fluid was used.