Have You Opened KDSS Shutter Valves While Performing Suspension Work?

[DougR]

I’m about to install a mild lift on my 2011 Trail with KDSS. My local performance lift shop does a lot of work for Toyota dealers, and I was hoping they would do the install, however they refuse to touch 4Runner KDSS accumulator shutter valves and they also refuse to do anything if the vehicle ever leans to one side after the install. They will adjust lean on a Land Cruiser, but not a 4Runner, saying the latter KDSS system cannot be balanced.

I’ve read a lot of forum posts and how-to’s by Toytec, Bilstein, Fox … it appears Dobinson is the only one to recommend opening KDSS shutter valves during any and all suspension work. Has anyone on this forum followed these instructions for front/rear suspension work?

 

[Sundy]

I’m about to install a mild lift on my 2011 Trail with KDSS. My local performance lift shop does a lot of work for Toyota dealers, and I was hoping they would do the install, however they refuse to touch 4Runner KDSS accumulator shutter valves and they also refuse to do anything if the vehicle ever leans to one side after the install. They will adjust lean on a Land Cruiser, but not a 4Runner, saying the latter KDSS system cannot be balanced.

I’ve read a lot of forum posts and how-to’s by Toytec, Bilstein, Fox … it appears Dobinson is the only one to recommend opening KDSS shutter valves during any and all suspension work. Has anyone on this forum followed these instructions for front/rear suspension work?

When I did my initial install (2.5" front / 2.0" rear) I did NOT open the shutter valves. What I did do is throw the truck in 4lo as I pulled into the garage, supposedly that opens the system. Before the rear coils settled I still had some significant lean. I used the Dobinsons KDSS coils to have built in offset for lean compensation.

Install was pretty easy, I did use ratchet straps up front to line everything up for assembly - see the Dobinsons thread for a bit more info.

After about 1,000 miles I had a minor amount of lean and decided to open the shutter valves. I follow the instructions to a T and it seemed to help just a little. I'm now perfectly level in the rear and approximately 3/16" difference up front (I've measured 1/8" and 1/4", depends on gas I think, so we'll split hairs lol).

 

[vt100]

Has anyone on this forum followed these instructions for front/rear suspension work?

I was following King's instructions to every letter when installing mine. They explicitly mentioned that there is no need to touch KDSS. I didn't even detach the front sway bar.

 

[DougR]

... What I did do is throw the truck in 4lo as I pulled into the garage, supposedly that opens the system...

KDSS valve/accumulator assembly has electrical inputs, so I'm wondering what happened when you turned the engine off with the transfer case still in 4Lo. Perhaps KDSS reengaged when the valves returned to a default position with the ignition off?

 

[Sundy]

KDSS valve/accumulator assembly has electrical inputs, so I'm wondering what happened when you turned the engine off with the transfer case still in 4Lo. Perhaps KDSS reengaged when the valves returned to a default position with the ignition off?

I'm not sure - another member had posted it here that it seemed to be softer for him (he has taken things apart a few times) so I figured it can't hurt to try.

 

[4hashiro]

I just did my 3" lift this past weekend. I did not touch the valves. You mentioned you're doing a mild lift, I changed out my UCA so it was quite simple. As long as you undo either of the control arms I dont think you will have a problem getting anything short of 3" in. The main KDSS lift thread writeup install does it by undoing the LCA, but a lot of posts in between found it easier to do the UCA.