I'd like to replace the actual PS fluid currently in my system with ATF, as I have read several posts that Toyota recomends this and it is easier on the seals. I have an occasional problem with the steering feeling heavy or slow. My thought is the lighter ATF might flow better, as I have replaced almost all of the PS system in recent months for various reasons.

My questions, how does one get all the old PS fluid out before adding the ATF? I can suck most of it out, but probably not all from the gear and lines. Do the fluids mix, or is that very bad?

If it matters, '91 SR5 V6 4Runner

Thanks

 

Elvota,

First of all, I highly doubt that the ps fluid you have in your ps system is anything other than ATF. In fact, my '03 states in the top of the ps reservoir, "replace with Dexron III ATF". So in a nutshell, you probably aren't going to gain much other than replace dirty, old, ATF in your ps system.

But, with that in mind, I've already replaced the ps fluid in my 'Runner. I've heard of people using turkey basters to suck all the ps fluid out of the reservoir, but I simply unbolted it and tiped it over into a container. I used a 1qt motor oil container with the top cut off to catch it. I followed this up by replacing the fluid with new stuff (Mobil 1 synthetic !), started the engine, turned the wheel lock-to-lock a couple times and repeated the process once more (after turning the truck off). Don't be surprised if your ps pump squeals for about 1 or 2 seconds when you do the lock-to-lock turn. This will be caused by air getting into the lines when you empty the reservior (if you dump it over like I did). This got most of the old stuff out of the system and I could see the fluid color change to a consistent red (if not the bright pink I would have liked).

Once you've done it, the process is pretty quick, if just a bit messy. The process above took about 30 minutes to complete.

Good luck !

Steve

 

The spec fluid for a 91 is Dexron-II ATF, so unless someone put something else in there you already have ATF. If you want to change it here's a write-up, it's for a 3rd gen but should be similar for yours.

http://www.tundrasolutions.com/forum...flush-writeup/

 

Eric, my writeup that you linked to is also posted at Yotatech here with a bit of extra information from replys. Like you mentioned already, it is a procedure for a 3rd gen.

I don't know how different it would be for a 2nd gen, due to the fact that 2nd gens don't have rack and pinion steering. I'll be finding out soon enough though, I guess, because I recently bought a '93 4R. As soon as I finish the required maintenance (read: brakes, suspension, etc...), I'll start tackling all the fluid changes/flushes and will have to educate myself on the differences from my 2002. It's a never ending process.

 

Thanks, I knew it was on here somewhere but I couldn't find it.
And you'll find more similarities than differences between the 2 Runners, I used to drive a 93 before I bought the 01, and I was surprised how much was the same.

 

Thanks for the tips and links. Gives me the information to move forward.

Such a good board.

 

Good to know.

 

I just disconnected the hose as started the truck.

Drained the power steering in about 0.0000001 seconds.



(Not really recommended - PS fluid everywhere plus possible damage to the pump. I was replacing the pump anyways)

 

One of my hoses is leaking and I was quoted by the dealership that the part costs $400 CDN.

That's how I keep mine fresh and clean I have to refill it once a month. Hah!

$400 my ass.

 

Sounds like you might have disconnected the pressure hose instead of the return hose. If not, than maybe the 2nd gen pump flow is higher than the 3rd gen... You did disconnect the return hose to the reservoir and not the pressure hose from the pump, right?

Did you have a helper, or were you trying to do it by yourself? When I did the one on my 3rd gen, it would have been tricky if I was by myself, because you can't see the drain bucket under the truck from the driver's seat.

It won't hurt the pump to run it dry for a second, but prolonged running with no fluid will cause scoring in the pump body and wear on the vanes.

 

I was doing it myself, no helper. I don't really recall which line it was - probably the pressure line.

 

GSGALLANT: In your write-up, you mentioned that of the need to turn the steering wheel from lock to lock. When doing this, should the engine be running or not?

Thank you.

 

I suggest to not have the engine running for that step. I've done it both ways, and it drains way too fast with the engine running. You'll achieve the same whether the engine is running or not, but you'll introduce less air in the system and you'll waste less fluid if you do it with the engine off.

Like the writeup says, I drained the reservoir with a turkey baster, disconnected the return line to the reservoir and put the return line into a container (plug the port in the reservoir when you disconnect the line), refilled with new fluid, started the truck for a couple of seconds just to purge the pump and lines of old fluid and replace it with new fluid (this will only get the fluid down to the control valve at the steering rack... it will not flush the fluid from the rack.) All this achieves is less lock-to-lock steering cycles to flush out all the old fluid.

When you get to doing the lock-to-lock steering step, to flush out the rack, you pretty much don't have time to turn the steering wheel to full lock before the reservoir runs dry if the PS pump is running, which is why I prefer to do it with the truck off. You still move the same fluid around, just under less pressure and with less wastage.

Just keep an eye on the reservoir and refill it each time is gets close to empty as you're doing this, and bleeding the system will take no time at all when you're done.

 

I just thought I'd update this thread to say that it works the same way to do 2nd gen 4Runners without rack & pinion steering. I didn't bother starting the truck at all to do my '93 4Runner, though.

Right after I refilled the reservoir after having removed the return hose, I just went from lock to lock three times, and by then, new fluid was coming out of the return hose. I did it one more time for good measure, then connected the return hose to the reservoir, topped up the fluid, and bled the system.