My 3.4 has been having this really bad squeal happening upon start up and tends to last until the car warms up and sometimes last longer than warmup. I was pretty sure it was the power steering pump, so I replaced it with a brand new pump. I thought it was power steering because my steering was jacked up and would required quite a bit of turning power. So I replaced the pump and it fixed that problem for the most part, still does it on rare occasion. But the squeal is still there. It went away for a day or 2 and then came back. I rechecked belt tightness and all seems well (I have about a half inch of play in the belt.) I have thought that it might possible be the A/C pump making the noise. I have no clue, and I know it is difficult for anyone to help without hearing it...let me know if anyone has had any similar issues.

 

Dumb question, but did you use power steering fluid or automatic transmission fluid?

 

Power steering fluid...and I bled the pump while the truck sat on jack stands.

 

Get rid of it and quickly. Toyota uses Dexron II ATF for power steering, since power steering fluid has a nasty habit of eating away some of the seals.

 

so hopefully i haven't done any damage. I've probably driven about 200 miles on it with power steering fluid. On the cap I swear it said power steering fluid. So I should use Automatic Transmission Fluid?? Can anyone else verify this...not that I don't trust you Rob, I just don't wanna go through the hassel of changing it out if i don't have to.

 

yeah like what rob said get rid of it now, it amazing how fast power steering fluid will mess up the system, use dextron atf it says it right on your cap in small print

 

ok cool! Thanks for the help I will try and change it out within the week

 

I know this is an old thread, but I changed out the fluid and it didn't help at all. But I don't know why I didn't notice it before, but my A/C belt was super loose and was causing my squeal. I guess I was just being lazy cus it was super easy to fix. Who knows, maybe I was just so sick of my truck I had no desire to work on it.

 

So I realize this is a super old post, but I am working on my 90 4R 3.0 and when I start it up, it has a awful squeak. then when looking at the belts, the alternator belt pulley is hot after only 30 seconds of the car on. the belt appeared to be tight. what could this mean?

 

Alright, so my belts will squeak on start up, and then after a minute they calm down, and then when i turn my head lights on, it starts squeaking bad again...does this mean I have a bad alternator? Thanks for all the help I can get.

 

Possibly, take the belt off and try to rotate the alternator by hand, it should have some mild resistance but not be incredibly difficult to turn. While the belt is off try starting the motor and see if the squeak is still there. Also how tight is the belt on the alternator?

 

Thanks the help. I will go try turn turn the alternator soon. The belt is tight. Meaning i has the adjustment bolts loosened, and with one hand I pushed the alternator and with the other I tightened the bolts. How tight are the belts supposed to be?

 

Thanks for the tip... I went out there and took the belt off, cranked it by hand, and put the belt back on, the squeak is not there anymore. Thanks for the help.

 

That didn't make any sense. Just because you turned it by hand then put it back on, the noise is gone?...

 

squeek is gone probly because he tightened the belt more than it was previously.

 

Yeah, I am not sure why it is gone.. I may have tightened it more, as I had a buddy here helping me pull the alternator back in place, versus me trying to pull it tight, and tighten the bolt. But thankfully it's not making the same noise as before.