KDSS Shutter valve?

[Olgx460]

Do you really need to Jack up the GX before you loosen the shutter valve when installing a lift? really makes no sense to do that after you Jack the vehicle because you tighten them up on the ground which is a different state of load on the KDSS system.

 

[Jetboy]

Do you really need to Jack up the GX before you loosen the shutter valve when installing a lift? really makes no sense to do that after you Jack the vehicle because you tighten them up on the ground which is a different state of load on the KDSS system.

I think the answer is no - you don't need to jack up the vehicle before opening the KDSS balancing valves. The function is to allow the pressures to balance between the upper and lower chambers. I think you'd want that to be balanced sitting at your finished ride height. I'm not sure you really need to do anything with it until your lift is done.

The tendency to create a lean results from the upper chamber having a larger effective piston area than the lower chamber (because of the piston shaft). The result of balanced hydraulic pressure on top and bottom but imbalanced piston area means more downward force on the piston shafts. Re-balancing the pressure doesn't really do a great job of fixing this. Ideally you'd compress the driver's side before it's closed so when the vehicle returns to normal ride height the force applied in both chambers on the piston shaft is balanced - ie balanced force on the pistons so they are at equilibrium mid stroke at final ride height. But there's not an easy way to do that that I'm aware of.

In a perfect world Toyota would have used a double ended cylinder or a 4 cylinder symmetrical system like Mclaren does.

That said - probably 99% of lifts never touch the KDSS system and it seems to work okay. The adjustable height air suspension seems to function just fine at different ride heights without adjusting anything, so maybe it's not necessary at all.

 

[Olgx460]

the reason I want to open the KDSS valve is to increase the articulation, make the install easier.

 

[Jetboy]

In the front you'll need to disconnect the sway bar from the lower control arms either way. In the rear it's not necessary or probably even useful to do anything with the sway bar.

 

[Washingtontaco]

I installed my suspension one end at a time, front first then rear. Only lifting one end at a time. I didn't open the shuttle valves but I did disconnect the stabilizer bar at the fixed and actuator points and supported the stabilizer with a bottle jack. This allowed the suspension to droop. Toy Tech demonstrates it in a video on YouTube. Makes life easier.

 

[jmanscotch]

I installed my suspension one end at a time, front first then rear. Only lifting one end at a time. I didn't open the shuttle valves but I did disconnect the stabilizer bar at the fixed and actuator points and supported the stabilizer with a bottle jack. This allowed the suspension to droop. Toy Tech demonstrates it in a video on YouTube. Makes life easier.

This is mostly what I did. I planned to open the valves but got started and forgot. No lean after.

Installed lift on rear axle first, then front. On the rear axle, do the driver side first then the passenger (just has to do with axle droop and space limitations). Completely disconnected rear sway bar on both drivers and passenger side, goes right back up in place, no problem. Make sure to align the sway bar bushings correctly. The front was a bear, but I didn't do anything up front. Didn't loosen LCAs nor did I touch the front sway bar at all. Assembled the struts, replaced the UCAs with JBA upper control arms and forced the new setup into place...so it's doable, just keep a large pry bar handy to work the bottom strut mount in.

 

[Olgx460]

jmanscotch . On the money! The JBA arms were easy to install for me, just had to pry them apart just a tad to get the washers in. I’m still working on the rear tweaks.