mmcpeck

Seems like every truck I get has P/S fluid in the P/S pump instead of the correct ATF that should be in Yota's.

My '88 Pickup, my '91 Runner and now my '92 Pickup....all have had P/S fluid in the pump when I got them. Never really cared before, but I've noticed with the recent cold, that when I start my truck in the morning that the P/S pump makes noise and sounds labored when first started cold, so I want to change it out and put ATF in.

Why do these Yota pumps always get P/S fluid dumped in them instead of ATF?

Is changing the fluid out as simple as sucking the P/S fluid out and dumping ATF in?

abecedarian

They get PS fluid because of idiots that don't know the difference and can't read what the cap says... and changing the fluid is that simple- dump the PS fluid in there and refill with ATF / Dexron II/III (or DexMerc as appropriate).

ilostmypants

now that i think of it i think i have ps fluid in my truck to! FUDGE!

whats the easiest way to drain it? crack one of the low pressure lines and let it drain? fill up the res. start the truck, crank the wheel side to side then fill to full then drain and fill again to make sure you just have atf in there?

im sort of just thinking out loud here im pulling an all nigher to finish an assignment i should be doing so its 5 am here, tell me if any of that sounds dumb

mt_goat

You basicly got it, just don't let it run dry, the pump will empty the res very fast.

shaeff

I would use a turkey baster to remove all the PS fluid, drain the lines, then refill with a quality ATF. Run the truck for a few days, and do it again. Then again, I'm very thorough, so do what makes you feel warm and fuzzy.

On a related note, here's a funny story for ya:

A guy I work with has a slight P/S leak. He asked me to figure out what the whining was coming from his engine bay. I diagnosed the leak, and the whine as low PS fluid/ pump whine. I told him: "Go to the parts store, get ATF... yes, automatic transmission fluid, and top it off. The whine will likely go away and you don't have to worry about losing your PS down the road somewhere.

He came in to work the next day and said the following. "I couldn't find any PS fluid that said ATF on it so I just got regular PS fluid."


:FACEPALM:

sb5walker

To do a thorough job, you need to also replace the fluid in the gearbox and lines. As mt_goat said, when changing the fluid, be sure to not allow the reservoir to run dry. When running, the pump can empty the reservoir very, very quickly. Here is a good how-to on changing the fluid in a Camry that doesn't require running the motor - I imagine the same technique would work for our trucks (but I haven't tried it):
http://www.toyotanation.com/forum/sh...ad.php?t=19334

But if that technique doesn't work, you can always do the following:

1. Remove as much fluid as possible from the reservoir using a (clean, dry) plastic pump or a turkey baster.
2. Pull the fluid return hose off the pump and route it down into a drain bucket. Plug the fitting on the pump.
3. Refill reservoir with your new fluid.
4. Start the engine and immediately turn off. Refill fluid level. If none has gone down, repeat this step and turn the steering wheel a little bit while the motor's running, but BE CAREFUL! The fluid can go down very quickly, and if you think the pump's making noise now, try running it dry, lol.
5. Be mindful that the fluid, once running, might continue to siphon fluid out of the reservoir, in which case you just need to keep refilling it.
6. Continue the cycle of very brief running/fluid refilling until you've used about a quart and a half of ATF.
7. Make sure reservoir is at the proper fill level for cold fluid and reattach the fluid return line.
8. If you allowed the reservoir to run dry, you probably introduced air into the system, and will need to bleed the system per the fsm. You will find this is no fun, so best to avoid.

Any Dexron ATF will work but Castrol Import Multi-Vehicle Automatic Transmission Fluid (ATF) is an excellent conventional Dexron III compatible fluid that is more viscous than most and is often recommended for power steering. Or if it's leaking, try Castrol's High Mileage ATF, same product but with seal conditioners:
http://www.castrol.com/liveassets/bp...pds_HM_ATF.pdf

The Castrol is better than most conventional ATFs in cold temps, but with a -40C viscosity of 13,000 cP (lower is better), it is not recommended for extreme cold. An alternative ATF for leaking systems is Valvoline's MaxLife Dex/Merc ATF which is full synthetic. It has a -40C Brookfield of 8400, which should be good in all but the coldest temps. Unfortunately it's thinner when hot, too - 100°C, cSt of only 6.11, vs 7.4 to 8.0 for all the other ATFs listed in this post:
http://www.valvoline.com/pdf/Maxlife_ATF.pdf

If the vehicle is operated in very cold environments, there are two synthetic ATFs that flow much better than most at very low temps, yet still have excellent viscosity at operating temp. The best cold temp performers are the Red Line D4 ATF, with -40C viscosity of 5200 cP:
http://www.redlineoil.com/product.aspx?pid=51&pcid=9

And for you Canadians, the Canadian market MOBIL 1 SYNTHETIC ATF with 5190 cP:
http://www.esso.ca/Canada-English/Fi...thetic_ATF.pdf

The U.S. Mobil 1 ATF has a different but still very good formulation, and it flows better at cold temps than non-synthetics, but not nearly as well as the Red Line or Canadian Mobil 1. It has a -40C viscosity of 10,040 cP:
http://www.mobil.com/USA-English/Lub...hetic_ATF.aspx

AMSOIL Synthetic Automatic Transmission Fluid is likewise an excellent fluid, superior to non-synthetics, but like the U.S. Mobil 1 it is not the best low temp performer at 9800 cP:
http://www.amsoil.com/storefront/atf.aspx

I've used the U.S. Mobil 1 ATF for several years now and I initially worried a bit about seal issues because it's a synthetic, but I've had no leaks or other problems. I've had no major trouble down to 0 deg F, but I notice at that temp the steering is a bit balky at first. It's fine once it warms up.

Junkers88

The PS reservior (spelling?) on my 86 pickup said "Use Dextron Type II Power Steering Fluid".

sb5walker

The Dexron III spec is inclusive of the earlier specs - it's fine to use.

mt_goat

Good luck finding anything called that.

mt_goat

Good post, I couldn't open the link, but I was able to flush my BMW PS system (rack) without starting the engine. One more tip is to get the front wheels off the ground so you can easily cycle the steering lock to lock with the engine off.

sb5walker

Here's the address without the http://

www (dot) toyotanation.com/forum/showthread.php?t=19334#post664821

mt_goat

Thanks, the link worked the 2nd time I tried it. I like the shampoo pump bottle idea! I hate turkey basters, they always dribble all over the place on me.

mmcpeck

So if you just suck the resevoir dry with a big syringe or baster, will you let any air into the pump or can that only happen if it actually gets run dry and pulls air in?

Also would the turning from side to side with the front wheels in the air work for a gear box the same as it would for a rack?

Saw mentioned in the above link that factory Toyota PS fluid is just un-dyed Dexron III, and that regular PS fluid is basically just low grade un-dyed Dexron III.

Anybody know if that's true, does Toyota used un-dyed Dexron III in the P/S at the factory and is regular P/S fluid basically un-dyed Dexron III?? I always thought regular P/S fluid was just brake fluid.

Thanks.

mt_goat

You have good questions, I guess its mainly only a problem if the pump is running but I suppose its possible to drain the whole system without even turning the key. I don't know the other answers, off hand.

sb5walker

No, emptying the reservoir won't get air in the system - you have to run or siphon the pump dry to do that. Plus, most or all of the Toyota P/S Pump reservoirs have a filter screen in the bottom that prevents you from completely emptying the reservoir.

Conventional power steering fluid and ATF are both mineral oils, similar to motor oil. The difference is that the ATF has important additives including: rust preventatives, anti-foam additives, detergents, dispersants, anti-wear additives, anti-oxidation compounds, surfactants, cold-flow improvers, high-temperature thickeners, gasket conditioners, and petroleum dye. P/S fluid lack most of those and will not protect your pump and gearbox adequately.

Brake fluid is a blend of various glycols, related to antifreeze, toxic, and totally incompatible with ATF or Power Steering Fluid.

mmcpeck

Wow, sounds like there is no need for P/S fluid to even exist then. Why would you ever need to use P/S fluid if ATF is so much better for the system, and P/S fluid has nonce of hese thing in it? Why is it even sold anymore?

There are P/S systems that can use DOT 3 brake fluid's though right?

ilostmypants

so yesterday i asked my prof about if having P/S fluid in a power steering system designed for ATF is bad and if i should be jumping on flushing it, he said as long as you haven't mixed p/s fluid and atf you should be fine.
(every time you mention ATF to him he goes on a rant about how all atf is is really high quality oil. and good for almost everything)

so i am now in less of a rush to change my fluid but ill get to it eventually just not when its so cold in the garage haha.

mmcpeck

Well that is true about ATF, being a high quality moneral oil, but it also has a ton of additives in it.

I would think that if it originally was filled with ATF, and then has gotten some P/S fluid dumped in it over the years, that it is pretty much a mix of both in there. Which I don't like.

mmcpeck

So does anybody know about the un-dyed Dexron III? Is that what Toyota puts in the P/S at the factory?

After hearing that, I am not sure if I have P/S fluid in there or if it's un-dyed Dexron.

Also it was mentioned that mixing the Dexron and P/S fluid is not a good idea. If I was just to suck the pump dry with a syringe and replace with ATF, and there was still some P/S fluid left in there (if I even have P/S fluid in there) would this cause an issue?

Wardamneagle

If you want to change the fluid in a more controlled manner, then jack up the front of the vehicle until both front tires are barely off the ground. Then follow the above instructions but don't start the engine. All you have to do to circulate the fluid (and thereby drain the reservoir) is to turn the steering wheel side to side slowly. As soon as you stop turning the steering wheel the fluid will stop draining. It really only takes a few minutes to completely change out the fluid using this method and it isn't messy at all. I think I had to refill the reservoir 3 or 4 times until new ATF started coming out of the return line that I had disconnected. It obviously helps if the new ATF is a different color/shade than the old fluid.