New here so forgive if my search skills suck and I just haven't found the relevant threads yet... but much to my chagrin I discovered that one of the 6 places my power steering system was leaking down onto my alternator was from this lovely and highly overpriced ($1200) speed sensing solenoid p/n 44170-30120. I can't imagine it's actually worth the effort to go pick and pull one with the 25 y.o epoxy in any of them surely degrading at this point right? So best bet is e-bay JDM new OEM for $400.. Much easier to swallow but the wait sucks. I just find it hard to believe that there aren't any clever community work arounds after this many years and a price like that for such a silly thing.. a convenience item that always ruins other vital systems because material choices and application sucked.. so it stalls out our "super reliable" toyotas in intersections like lazy 40 y.o Ladas . Par for the aging luxury car course I know and I should shut up and order it so I'm good for another 150k.. and I will. But in the meantime I perhaps misguidedly soaked the seepy degrading rubber capped end with a few layers of thin CA glue deep down into the pores of the old leaky butyl.. then capped it with high heat epoxy.. thinking that might save my alternator for a week or two ha.. I know I'm supposed to put a clorox bottle or bud light can over my brand new Denso alternator too so it overheats itself instead of shorting out with ATF but something about redneckedness of that on my precious makes me want to spend $400 on a stupid solenoid and drive my buzzy miata for a 2 weeks instead. Point really is that the steering has been heavy since I bought it and I'm honestly fine with it being stuck on stiff.. never even realized it was supposed to be speed sensitive. I'd be great with a cheap leak free delete but I don't see anyone doing that.. Can you just plug it like the idle air control port? And to complicate it further Lexus won't even sell you the weird 3 O-rings on the sensor while at the same time forbidding us in the FSM to ever reuse any O-ring lest the heavens fall.. The local hydraulic shop fortunately got me close with a 17mm 18mm and 19mm but they aren't perfect.. we shall see if they seal. Just looking for some informed opinions though.. someone smarter has been through this.. any links to relevant threads or vids?

Leaky steering speed solenoid

 

Hello,

Between the Hydraulic Brake Booster and a Series Connection of all the ECUs in the Interior, GS has always been a car rather .. uncharacteristic for Toyota, that would be one way to put it..

Power Steering is no exception to that statement - yes, it does have Progressive Power Steering, but with the way they executed on it, I'd much rather if they never bothered with it in the first place. Normally, the Solenoid that you are looking at is located on the Steering Rack, where its task is to Redirect some of the Flow created by the Power Steering Pump back into said Pump, that way you are effectively reducing the Flow produced by the Pump, thereby reducing the Force that it can use to "help" you turn the Wheel.

In your case, however, Toyota decided to go a different route and installed said Solenoid on the Power Steering Pump as you can witness, thereby instead of Redirecting part of the Flow, it quite literally Blocks it from exiting the Pump, such that instead of simply moving the Fluid around with barely any load, it essentially chokes the Pressure Line until the Flow is right, and relies on the Emergency Relief Valve to maintain the right Pressure in the System. This approach causes the same increase in Pressure as when you keep pushing on the Steering Wheel when it's turned fully to one side, with a slight caveat that this Load is present the entire time you are going above 60mph, even when you are going Straight. It is a terrible design that is only waiting for the failure, it should've been quite clear right from the start, but they still decided to soldier on regardless.

The issue for me in particular is not even that it is a bad design, mistakes happen, it's the fact that they have already done it properly years before, and on a whole range of different cars. Without even counting all the JDM cars that came with this option, the entire LS lineup had Progressive Power Steering installed from its very start in 1989, and all of them had the Solenoid on the Rack, even the Previous Generation GS came with the setup identical to the latter. The 2nd-gen GS is the only oddball in this lineup, even its JDM counterparts, like Crown Majesta that donated the entire Platform to the GS had a better design. Despite looking into it, I still can't come up with a good explanation of what made them choose this route, compared to an already proven design that is still used today.

Either way, getting back on topic, 3rd-gen LS400 and 2nd-gen SC400 had an identical Pump to your GS, the only difference is that it only has a Straight Fitting on the Outlet of the Pump, instead of the Solenoid and the 90° Elbow attached to it on the GS, here is a thread with more information. If you are not particularly interested in dealing with your Solenoid, it may be worthwhile to find a 3rd-gen LS, or a 2nd-gen SC at the Junkyard and simply take the Outlet Fitting off of one (here is a Parts Catalogue for a 2000 L400, Part Number for it is 44338-24080), that Fitting should fit right into your Existing Pump, and will replace both the Solenoid and the Elbow.

That said, however, therein lies the rub too, going this route, you are Eliminating the 90° Elbow, the Port will now come straight out of the Pump, which means that you will have to do some clever trickery to bend your existing Pressure Line into the right shape to hook it back up to the Pump, and I am not particularly sure if it is doable at all. It's a Steel Line, which really doesn't help with Flexibility, it is also Crimped together throughout its entire length, so if it folds as you bend it, you will have to replace the whole thing for another attempt, which can get rather complicated.

The question here really is which one would you rather deal with - the unobtanium Solenoid, or the Steel Pressure Line. The other thing to consider, as blatant as it is, getting rid of the Solenoid will also get rid of the Progressive Power Steering, but honestly, in my experience, it really doesn't make that much of a difference anyway, especially with the way it is done on those cars. Either way, the choice is yours..

Hope this helps and best of luck!