Variable assist power steering

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asutherland

asutherland

VA7 HDT
10 Year 15 Year
Joined
Apr 23, 2010
Threads
285
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3,275
Location
Kamloops, BC
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www.forgottenbc.ca
My 93 has variable assist power steering. Or maybe an idle up system. Does anyone have a manual with the details of this system? I would like to know how it works, how it affects steering, and what the resistance on the valve/sender on the box should be at while off, running, turning etc.

Nothing in the 96 USDM chassis manual, the EWD, or my 1992 HDJ81 manual. Searched here and the 80 series section and found nada.

thanks! :)
Andrew
 
Did you look in the Body Chassis manual? It has pressure testing results for various rpms and tips on diagnosing the control valve. Also has diagrams
 
@roscoFJ73 , I checked 1996 Toyota Land Cruiser Repair Manual v111, and fj_hdj_hzj-80_series_chassis_1992_RM315E but couldn't find anything.
 
my HDJ80 have none of that .. just a basic PS pump which turns out to be the same as you found in the 1FZ ..
 
My understanding after reading some more FSM is that when the vehicle speed reaches a certain value (48km/h or something) it applies 12v to the solenoid on top of the steering box, which bypasses the flow a bit, resulting in "firmer" steering more suited to highway driving.

I wonder if mine gets "stuck" sometimes.........
 
The way I read the manual is that the further you turn ,the more the valve opens and the more fluid is diverted to assist the steering. At highway speeds ,you never move the wheel much more than an inch from TDC,so the valve is only partially open and giving you that firmer feel.
Adding a solenoid would just complicate something that works well.
Your steering box would have wiring going to it if it has this solenoid.
Ive only looked at an Australian manual
 
I found it in my manual at the back but I haven't seen or heard of one before. Can you see it on your steering box
 
Yeah. Two wires thst go to the top of the box. I can take a pic of it tomorrow in the daylight.

I'm not sure there's anything wrong with it, I was just testing a bunch of fsm stuff for why my steering might be inconsistently difficult at random times at idle or low speed. Checking this solenoid was apparently one of the things that can cause these symptoms. The PS pump I rebuilt a couple years ago.
 
What speed do you have it idling at?
 
Tried both 750 and 950.

Update, I ran the fsm test of checking the solenoid by applying voltage and ground directly to the connector and listening for the solenoid click. There is nothing. I think it's dead. Now to see how absurdly expensive the solenoid and valve is...
 
Pic

IMG_20161112_164535.webp
 
[QUOTE="asutherland, post: 10671148, member: 54767" I think it's dead. Now to see how absurdly expensive the solenoid and valve is...[/QUOTE]

Get the part number, it may have a use elsewhere
 
Update on my steering box. Thankfully, John at @Radd Cruisers had an extra complete box available, with ecs solenoid valve, and we swapped it in this weekend.

Amazing! So that's what power steering should feel like. Turns my big tires with one finger.. Even while at a standstill. I always thought there was an issue with my pump, which is why I rebuilt it a couple years ago. Turns out it was the box. Cruiser drives like a new vehicle now!

I haven't benched and opened the old box yet to see if it was the valve, gears or solenoid, but I eventually will.
 
So, I lost my power steering last year.
Took a long time to finish the power steering pump rebuild I thought I needed.
During the reinstallation it seemed to still not be working. So, remembering Andrew's struggles, I looked up this thread and pulled my variable assist valve solenoid.
It passed the continuity test, but failed the applied power test. No clicking.

Filled it with penetrating oil and let it sit for most of the day. When I came back to it, it passed the applied power test.

I reinstalled the newly cleaned valve and the rebuilt power steering pump.
(After one drastic issue that had to do with me improperly rebuilding my pump) everything tested fine and the system was bled.

Goodbye Armstrong steering. Instead of needing two hands to turn my steering wheel I can do donuts with just one finger. What a treat!!!

Long story short. If the variable assist valve is failing tests give it a good cleaning. Might save you some money.
Also, give your steering system some love. It's easier on your triceps and forearms.
 
ozwallaby said:
@ dana..... What exactly was the mistake you made in the rebuild initially..... a detailed rundown may help others in avoiding a pitfall..... or is it another thread..
Click to expand...

I missed some parts in the rebuild. there was a new oil seal and a snap ring that were in the bag of old parts from the pump. and I didn't read the FSM as I was putting it together. Just slammed it together and slapping on the truck, in my excitement to end a year of armstrong. steering. I couldn't understand why the ATF kept disappearing, but didn't know the capacity of the system. I lost litres and litres of ATF into my oil pan through the pump. REVISIT THE FSM FREQUENTLY
 
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