So, for a while now, i have been experiencing stiff steering, i have changed the fluid several times, but it ends up turning dark within a short while.
and i jack up the front wheels, turn the steering wheel, while topping up the reservoir, till red fluid comes out [i use dex 3], but within a week, < 70miles, the fluid turns dark again. any clue to what may be causing it.

i threw in a new pump 2 days ago, my stiff steering problems are gone, but today..i check again, the fluid is already brownish red again

Might be the new pump seating itself in with some initial wear. See if the color stabilizes somewhat over the first month. I try and syringe out the reservoir every oil change and add new ATF. It comes out through the clear tube red but when put into a little jar I collect it in it's dark reddish-brown as you say.

I've never had to replace a p/s pump and have 3 Toys, lowest mileage 140K and 17 years old, highest 220K, 13 years old.

Did have the stiff steering you mention but it was the steer shaft u-joint just above the steer gear, new shaft and great!

I've never had a PS pump failure in my 2005 SR5 4runner/150,000 miles.
I have siphoned off PS fluid when it got slightly dirty once or twice. Currently it is 90% clear.

Poster that has dark PS fluid and black PS fluid has "seals" failing somewhere IMO.

Chrisfix https://www.youtube.com/watch?v=VuPALAnHjRM

You say the fluid is "90% clear", so are you using "power steering fluid" which is clear or are you using transmission fluid which it clearly states to use for the power steering on the reservoir cap and in the owner's manual??

I use clear power steering fluid, not red tranny fluid. My 4 runner came new from factory in 2005 with clear PS fluid.

Universal Steering System Lubricants - CARiD.com

Power steering fluid colors What is Power steering fluid color Should Be?

Mine is clear/amber also and it was like that on my 4th Gen too.
http://5th-gen-t4rs/117098-power-ste...fluid-atf.html

I find that hard to believe since in the owner's manual it says.....

"Check the fluid level through the reservoir. If necessary, add automatic transmission fluid DEXRONII or III.
If the vehicle has been driven around 80
km/h (50 mph) for 20 minutes (a little
more in frigid temperatures), the fluid is
hot (60C—80C or 140F—175F). You
may also check the level when the fluid
is cold (about room temperature,
10C—30C or 50F—85F) if the engine
has not been run for about five hours.
Clean all dirt from the outside of the reservoir tank and look at the fluid level. If
the fluid is cold, the level should be in the
“COLD” range. Similarly, if it is hot, the
fluid level should be in the “HOT” range.
If the level is at the low side of either
range, add automatic transmission fluid
DEXRONII or III to bring the level within
the range.
To remove the reservoir cap, turn it counterclockwise and lift up. To reinstall it,
turn it clockwise. After replacing the reservoir cap, visually check the steering box
case, vane pump and and hose connections
for leaks or damage"

There is 2 different versions of the 2005 T4R owner's manual depending on the build date of your 2005 T4R.....but on page 381 in both versions is says the above.

Here's links to both versions of the 2005 T4R owner's manual in PDF form directly from Toyota's website, again look on page 381 in either or both the see the text I posted above concerning what fluid should be use in the power steering pump.

https://www.toyota.com/t3Portal/docu...f/OM35843U.pdf

https://www.toyota.com/t3Portal/docu...f/OM35860U.pdf

Are you removing the return hose and filling the resovior as you fill it until the fluid coming out the unhooked return line is red?

Power steering system is essentially a closed system with no major contaminants (like combustion you see in engine oil) so you shouldn't be seeing substantial fluid change if you have done a complete flush.

My suggestion would be to have an oil analysis done through Blackstone Labs or Wix (it's ~$12ish through Rock Auto or NAPA) and see what's going on.

Vavoline MaxLife ATF, not PS fluid.

4runners did not come from the factory with clear PS fluid. the fluid may have looked more clear than red but was likely dex3 or equivalent, but it was not the clear PS fluid they sell at auto parts stores.

the original fluid in my truck was clear fluid, that got gradually dark & i changed it..about 3 years ago

Hmmm, the second person that says the fluid in the power steering was clear when their T4R was new.

I still don't think the clear fluid was clear "power steering fluid" but instead ATF without the red dye that has been added to all ATF since around 1968 to avoid confusing it with regular motor oil.

why is transmission fluid red - Bing

Automatic transmission fluid - Wikipedia

this is correct. toyota does not use clear power steering fluid, its a bulk bought clear dex 3. they would not fill the p/s with actual power steering fluid, then tell owners to use dex 3.

if you are using clear power steering fluid you buy from auto parts stores, you are using the wrong fluid.

didnt buy new though, bought used at 115k miles, however my pals o7 also has clear power steering fluid, also bought used.

my 04 rav4 also has clear power steering fluid.

2ndly, observed my truck has developed a squeal,and a constant slight tap tap sound after the power steering pump replacement, however, the belt was already damaged by the time, i opened the hood to investigate - i then saw that the repair shop messed up, the lowest pulley, the placed the belt groove down on it.

after searching through the forum, i was able to replace the belt, with a GATES belt, but the squeak is still there, i checked the idler pulleys before installing the new belt..and they felt fine.

anyother way of tshooting this noise, apart from throwing parts at it??

Buy yourself a mechanic's stethoscope at your local auto parts store for around $10, then VERY carefully use it to locate the squeak/noise, every tool box should have one of these to find the exact location of usual noises that need attention.

The squeak could be coming from any of the moving mechanisms that are moving along with the belt, sometime even new parts could be making the noise.

i used the tyre jack extension pipe as a diy stethoscope, all 3 idlers sounded alike, i didnt check the new steering pump, since its new,{rockauto} guess will go and recheck it later.
the tensioner sounded a bit different too