Hello All!

If there is a idiotic piece of engineering, and my newly acquired '93 4Runner has a few, then the "Planned to fail causing catastrophic failure" engineering/design idiocy, the idle up air switch on the PS pump, is certainly one of them!

I acquired a 4Runner V6 with somewhat relative low mileage for the age 155,500. I bought it as a daily beater to replace my dying '86 Landcruiser with 360k miles. (Needs a ring job badly!)

Shortly after the purchase of the 4R developed various problems. One of them was increasingly blueish white smoke after a hot restart and the PS Reservoir starting increasingly to run rapidly empty resulting the pump started whine. But no leak anywhere!

Fortunately, being weary after the first incident I caught all subsequent in time before the PS would seize up and needed to be replaced. (Which would have not solved the problem)
Finally ever 40 miles I had to fill up the reservoir! but no leak anywhere!

CAUSE:
As many of you might know, cause was the failing idle up air switch on the PS pump allowing all oil to be sucked out into the intake manifold and combusted! (Maybe a reason for my smog emissions test failure)

WTF! What a piece of F@#$S%&*! engineering design just to get an idle RPM up a 100 or so revs when steering! Jeez! Really!

SOLUTION:
A metric bolt: M14 1.5 fine thread about 15mm long (mine is 30mm long), and a little pipe thread compound to aid sealing all!
Cost: $ 3.87 for the bolt. Plus a quart of ATF DEXTRON 2 or higher
Tools needed: a 22mm wrench
Tasks: Remove the battery to gain access. pull the two hoses off the switch and plug the 2 ports on the intake manifold. Untighten the air switch and remove it. Apply threadseal to the bold and screw it in. Tighten sensibly.

Result:
PROBLEM SOLVED FOR GOOD!

Effects:
No PS fluid loss at all. PS performance 100% as to be expected.
RPM drop? About a laughable 50 in idle end to end!

Sorry Toyota you failed! I won! You can't sell me an overpriced airs witch or new PS pump with your F uped design!
My liking of Toyota? Dropped by about 40% overall.

Now I wonder what other "engineering marvels" are lurking to fail as planned...



What you say to all this?
Any expertise or good knowledge replies are very much appreciated and I thank you in advance!

 

I had the same thing happen a couple years back on my Tacoma. It was the most perplexing thing because like you said, NO LEAK! I used a pretty long bolt and some Teflon tape on mine. Worked like a charm until I swapped out the stock line when I SAS'd.
I've got a thread on it too. I'd post the link but I'm on my phone so it's not exactly easy.

 

 

You can get an allen head insert instead so it doesn't stick out as yours does.

 

To think I just replaced those with new switches.

Your losing fluid out of the power steering system but it is not all over the vehicle only one place it can be going

To me the spare tire holder under the rear of the truck is far worse.

 

the nipple on mine broke, ziptied the vac hoses. I'm to lazy to remove and block it. lol