Installing Airlift 1000 on a Sienna (2nd gen)

[fibber2]

This past Sunday, I installed the Airlift kit on my 2008 Sienna LE (FWD). I’d like to claim that it only took me 2 hours or so (seems to be the current time target), but this Fibber would be fibbin’ if I lay claim to anything less than about 4 hours for the job. Probably because I was overthinking every step and redid much of it twice, so that might account for the 2x factor. In the end, I’m pretty happy with the outcome, but a little concerned that part of the routing near the rear left wheel well might leave the lines vulnerable to ice buildup. We’ll see if further mods are necessary as winter approaches. A couple of things I thought I’d post for others considering this:

1) I put the van up on jack stands, and removed both rear wheels. That allowed me to also install the rear mud guards that have been hanging around for several months. It also afforded me a clear & unobstructed view and access. I recommend doing so.

2) I began by cleaning the springs and seats. Metal burrs, rust spots and stuck on road tar are your enemy. The air bladders must slide with minimum rubbing and friction. I buffed the black painted metal clean, and applied a liberal coating of silicon spray. I even had to chisel off one little chunk of stray welded steel on a lower seat that would have surely ripped the bladder with time. I also sprayed the red bladder with silicon and wiped it clean. Yet despite this effort, I still hear some new creaks and groans from the rear in use.

3) I installed them valve up, with the air line entering thru the hole in the top seat, and the supplied red disk on top. When I lowered the vehicle the first time it was quite evident that the bladder fills pretty much the entire spring, and does push against the lower seat with no protection. I found that the round plastic lid from a quart takeout Chinese food container fit within the confines of the spring perfectly. I used some RTV to glue in to the lower seat, and the air bladder nested in place. It might not make a real difference, but it made me feel better!

4) Rather than attempt to make the connection within the spring, I ran the lines down into the spring and out the last coil with two feet to spare, and inserted the line and clamp with relative ease while sitting beside the van. I then carefully folded the bladder and inserted the completed assembly into the spring, making sure the line and disk snaked back up and everything remained unkinked. Again, the advantage of having the tire off. Oh, so how do you keep the bags flat for easy insertion? Snake all the lines first, compress the two bags, and plug them in. If everything is leak free, they will stay deflated!

5) I opted to have separate channels, so ran two lines with individual Schrader valves. Uneven weighted loads could have the effect of forcing air out of the heavy side and actually pumping up the light side. Not what you want! Even in a long sweeping turn the compression on the outside wheel could raise the pressure on the inside wheel, potentially increasing body lean. In our lab we have air suspension tables with feedback sensors and regulators. That hardware doesn’t exist here, so you need to adjust pressures to compensate, and only fully separate lines will allow for this. I thought about getting fancy and putting in a manual valve for easy equalization (I have one for this diameter hose), but figured that with a digital gauge I can fill them close enough to even (or offset if I feel the need).

6) Given the exhaust pipe running out the passengers side, I opted to run the right side line across the van following the hydraulic brake line attached to the body. At first I was going to follow the beam axle, but as the bags are mounted up and the top seat is fixed in place, it didn’t seem to make sense to then tether the line to a moving suspension parts. This does put it a little closer to the muffler, however. We’ll see if this was a good call or not…. I left a few inches of slack above each upper seat just in case I ever need to replace a failed bag.

7) Once over on the drivers side, the two lines run straight back on the outside of the seat well pan, next to the hitch mount, and to the rear bumper area. And that is where I ran out of line, so I ended up put the two Schrader valves in the rear valance a foot in from the left edge. To me, that is quite convenient, and well protected. The panel is reasonably strong, and doesn’t deflect much when pushed. I consider the kit to be a bit skimpy on hose, so be careful with your routing. If you go with my plan, you’ll need every inch.

8) You might notice that there isn’t much to attach the lines to when running along the outside of the van. I fabricated two attachment points. The first site I actually drilled a small hole in a thin metal spot along the weld seam. At the second there was a small hole in the outer sheet of a double layer panel, and I modified a plastic push rivet, added a plastic tie, and RTV’ed it into place. In retrospect, I’m afraid this run might be too exposed, and vulnerable to snow & ice packing. It might get a redo down the road.

9) I let my wife drive it today with 10 psi. Even with this little air, bouncing on the rear bumper produces less deflection. The static height of the bottom of the Curt hitch on an empty van is actually up about a half inch over fully deflated. She noticed no ill effects in driveability, but it wasn’t enough of a ‘lift’ to keep the van from bottoming out on a crude country driveway we regularly have trouble with. I guess I’ll try upping it a bit prior to next week’s flute lessons! We’ll have the van fully loaded in a few weeks, so that will be the real test.

Pictures to follow!

[fibber2]

Lets see if these adequately tell the story.

On the food lids - I did trim the little nubs away to provide a completely flat dish.