How to REPLACE power steering fluid?
 

Hey yotatechies:

How does one change the power steering fluid in a 3rd gen 4Runner? I am trying to replace the old power steering fluid with fresh new fluid.

Any thoughts would be appreciated.

We really never got a chance to completely drain and refill a p/s unit, although I wish I did. What we where taught is to jack up the two front tires (on the frame because you will be turning the steering wheel). Start the engine and disconnect the effulent line off the power steering pump at the reservior (in other words the "return" line from the reservior)mand drain the fluid into a pan as the motor is running, find a plug for the reseivor flange that the line connects to (they sell these plastic caps at Kragen's maybe you can use one of those). Make sure you use the return line and not the feed line. Our teacher told us to have an assistant turn the steering wheel from lock to lock until the fluid comes out no more or the pump start screeching. I personally thought this was a bad idea and I think instead you should do it until the reservior level drops to just a little bit left in it. I would not let the reservior dry up and let the pump operate on air, bad for the system. Stop the engine at this point and refill the reservior with ATF (automatic transmission fluid Dexron II or III), up until cold or hot mark on the cap dipstick, depending on whether you've driven the rig or doing this at a cold start. Start engine again, and when fluid begins to pour out the return line, drain down again the reservior until you still have a bit left and refill again. I'd probably do this about three times and then on the third time after I stop the engine, I'd take off the reservior plug and connect the return line back to the reservior. Once again refill up to cold or hot mark (more than likely at this point it's the cold mark since you placed new fluid). Then bleed the system.

This I have done, but on a Ford after replacing the rack and pinion. Same thing applies to a Toyota, after you make sure that the fluid is properly filled and up to the mark, turn on the engine and turn the steering wheel from lock, hold for like 2 seconds, then turn to the other lock, hold for 2 secs, now go to the reservior and look at the fluid and check the level with the engine running. Also make sure it isn't cloudy or foamy (it means you still have air) and if it is, re-do the turning the steering again from lock to lock. If it is still cloudy or foamy after doing this, you have too much air and what you need to do is go back and disconnect the return line, and allow fluid to drain out again, but you don't need to do alot, maybe just once and only go down to the "min" mark on the reservior. Re-check fluid level, re-bleed, and after bleeding make sure you check your fluid level as it may drop (actually it probably will). Good luck.

By the way, in class when we bled the system, the wheels where on the ground flat, as we turned them from lock to lock.

You know what, something I remember is my old 4Runner, when the P/S went, and the dealer (mind you :roll: ) replaced it, they didn't bleed the ABS system. At the time I didn't know this, but rear wheel anti-lock brakes are somehow integrated with the P/S system, hopefully one of these guys can direct you to make sure that my method (which is pretty standard) is okay to do for your year 4Runner, older models, I'm not sure...doing a lit bit of searching I found this and scroll down to read the warning on rear wheel abs.

[QUOTE=Mohamed] I'd take off the reservior plug and connect the return line back to the reservior. Once again refill up to cold or hot mark (more than likely at this point it's the cold mark since you placed new fluid). Then bleed the system.


What do you mean, "Then bleed the system"? Isn't what you are doing "bleeding the system?" Thanks for your help.

[QUOTE=jim1000]ya sort of, but when you connect the hose back up, you are going to entrap some air. Plus industry standards of bleeding p/s systems is to do it as mentioned above and to turn the steering wheel from lock to lock. That last step of turning the wheels on the ground when you're done, just adds assurance that your system is air free.

instead of letting the effluent line run dry, as the fluid get to the bottom of the resivoir slowly add fresh fluid, very slowy so the new fluid doesn't mix with the old or very little mixing occures and do this as the assistant turn the wheel lock to lock. you can stop doing this when the fluid coming out is clean. replace the effluent line and fill the resivoir. this way little bleeding is nesasary and no damage will ocurr to the steering pump