95.5-2004 Tacomas & 96-2002 4Runners 4th gen pickups and 3rd gen 4Runners
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Beware: Power Steering air control valve

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Old 12-29-2011 | 12:39 PM
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Exclamation Beware: Power Steering air control valve

Just wanted to post this as a little FYI in case your power steering fluid (ATF) is disappearing without signs of leaks or drips etc..

On the 95.5-00 3RZ there is whats called the "power steering air control valve" that is used to bump up idle when there is any steering input. This is done so as to not stress the pump.
When the valve is open, steering is straight, the air goes in and back out of the air control valve.
When the valve is closed, steering is turned, the air is "blocked" and thus creates a sort of vacuum leak that raises the idle a couple hundred RPM's which in turn increases pressure in the pump and lets you steer easier.

Somehow this valve started leaking and letting ATF from the pump go straight into my intake manifold.
I had to literally top off the pump after every 30-40 miles of driving or else the next time I started to drive I would get a horrible whine from the pump.
I ordered a gasket kit for the pump thinking that would solve it and after rebuilding the pump with all new gaskets nothing changed.
I finally was tipped off when after letting the truck idle for 20-30 mins (while airing up tires after wheeling) and then taking off there would be a huge blue/ white cloud of smoke coming from the exhaust.
I also noticed my oil level was overfull by about 1/2 a quart. The ATF must have gotten in the crank case too.

Anyway, after the long explanation, here are some pics of the damn thing.

The old valve, missing the vacuum hoses
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I crossed the hoses and then watched ATF pour out of the valve. BINGO!
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The new valve and the part number
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Here is a picture of an 01 3RZ power steering. You can see there are no vacuum lines leaving the pump and none going into the intake.
Picture courtesy of Johnnie
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01+ 3RZ's and (I THINK!) all 5VZ's use a different type of connection/ valve to signal the pressure/ idle increase.

The 03 3RZ FSM shows an electrical connector where the ACV is.
http://www.ncttora.com/FSM/2003/Repa...p2rzf/comp.pdf

The 03 5VZ FSM shows a different type of pressure switch. My 1999 Paper FSM shows the same type of connector like this on the 5VZ. So this must be the one setup they have. Feel free to chime in if you have an earlier 5VZ with a different type of connector.
http://www.ncttora.com/FSM/2003/Repa...p5vzf/comp.pdf


Old 12-29-2011 | 02:10 PM
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Toyota switched to an electronic vacuum idle up sensor in 1999 in the V6 4Runners. My 99 5VZ engine (that I am swapping) is electronic.

Tacomas and 4Runners with the 3RZ used Vacuum through 2000, then switched to Electronic in 2001 (the 4Runner was not offered with a 4cyl after 2000 however)

Last edited by DeathCougar; 12-29-2011 at 02:12 PM.
Old 12-29-2011 | 04:28 PM
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it happens on the 3vze,22re and 1uz also .... one other thing is those nipples for the hoses break really easy .. found that these air valves on the 22re are all metal. i am currently running a 22re metal air valve on my 4runner with the 1uz , my 4runner with the 3vze and my 22re 2wd pickup,direct swap, works fine!! not sure if its a direct swap for the 3rz though,looks like it would be .

Last edited by RMA; 12-29-2011 at 04:29 PM.
Old 12-29-2011 | 05:45 PM
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they are a direct swap, RMA. They use the same threads, and the part is in fact the same for all the engines you listed. Plastic, two nipple, with pipe threads.
Old 12-30-2011 | 08:04 AM
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Rehope this works ..posting from my phone at work..takes like 1000 steps
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the valve on my 2wd..

Last edited by RMA; 12-30-2011 at 08:06 AM.
Old 12-31-2011 | 07:40 AM
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Wow Steve. Glad you figured that out. Is the motor ok?
Old 12-31-2011 | 10:42 AM
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I dont think a little ATF would hurt anything. I know some people that run about a half cup in the oil to help gaskets. Dont know if its works or not.
Old 01-01-2012 | 02:16 PM
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Originally Posted by naksukow
Wow Steve. Glad you figured that out. Is the motor ok?
Runs like a top, man. Not much I could do if it actually did hurt it. Just run it till it blows.
I'm going to change the oil soon and then change it again soon after that for a flushing effect.



Old 01-01-2012 | 02:37 PM
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Couldn't you just leave the loop on there and get away with it?
I generally don't idle when I crank the wheel.
Old 01-01-2012 | 04:03 PM
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Originally Posted by sixstringslut
Couldn't you just leave the loop on there and get away with it?
I generally don't idle when I crank the wheel.
Could have, I guess. But with it looped fluid was still coming out of the valve, escaping out of the hose and dripping onto the alternator. Not ideal.
I could have just replaced the valve with a bolt of the same size and not worried.
But, I prefer to do things right. No need to jerry rig anything.
For $75, if I can get another 170k miles out of the valve then I think my money was well spent.


Old 02-14-2012 | 08:40 PM
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I have been wondering... does it matter if the the two vacuum hoses get switched? I cannot figure out which hose goes onto the right side of the sensor and which one goes onto the left side. I cannot tell the difference in the motor or in steering when I switch them but I would still like to install them correctly.
Old 02-14-2012 | 09:05 PM
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I continued searching and found the answer. It does not matter if the hoses are switched because they complete a loop from the plenum to the idle up valve when the valve on the pump opens during turning.
Old 04-10-2012 | 06:37 PM
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So it can leak through the intake
Old 04-10-2012 | 06:38 PM
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Into the cylinders?
Old 11-11-2012 | 01:28 PM
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I just discovered the same thing on my 1988 22re. 1st there was smoke on start up. I lifted the hood to have a look and found PS fluid pumping out one of the line that had popped loose under pressure. Looking for the part online, I found it's $300.00+! What the hell?
Old 12-16-2012 | 01:28 PM
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What does that valve actually do and does any one have a pic if were the vacuum lines go on a 85 22re cus mine wasn't hooked up when I got my truck hasn't gave me any probs but I would like it to be right
Old 12-16-2012 | 07:04 PM
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It controls your rpm's when turning at low speed so that the power steering pump does not drag down your idle speed.
Old 12-17-2012 | 12:31 AM
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Thanks bro I seen the lines and were the go
Old 03-11-2013 | 08:17 AM
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Anyone figure out where to buy these valves for a respectable price? 250$ is too much for my taste.
Old 03-11-2013 | 09:22 AM
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Originally Posted by Notraps
Anyone figure out where to buy these valves for a respectable price? 250$ is too much for my taste.
The part shown earlier in this thread is $70 plus $10 to ship here https://parts.tituswilltoyota.com/pa...r_search.html?


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