Unintended lift with air bags?

[swatski]

I had the Firestone coil-rite kit (W23760464) installed, and noticed an approximately 1” maybe 2” rear “lift” (even with no air pressure in the bags).
Any suggestions?
TIA!

I love the kit, but need to be able to get the truck down to the original height, 1-2” lower, as I started hitting the height bump at my work garage...

I talked to Brad at M.T. Shiele who did the install, they are not sure why that would be.
Pretty much followed the @linuxgod thread as in here, everything went smoothly and no issues with the install. Wonder if anything needs to be compressed?

You need to buy a Firestone 4164 or 4129 kit. The 4164 kit is actually for the LC and is preferred if you already have a lift and haven't installed these before. The 4129 kit is (basically) the same, but the bags are 1" taller and can be used if you installed the 4164 kit on a stock truck previously. The rule is:

• With the 4164 kit, cut off all 4 segments of the bump stop for trucks with NO lift.
• With the 4164 kit, cut off 3 segments of the bump stop with a 1" lift. @Dan Higgins this is what you want to do
• If like me you already cut off 4 segments of bump stops, you can buy the 4129 kit (which is for an 85 Buick), cut off all 4 segments of the bump stop with a 1" lift, and throw away the clamps and plastic spacer.

As far as the installation goes, any reputable shop could do it. The installation takes about 2 hours. The shop simply does the following:

• Remove the springs as if you were swapping them.
• Remove the rubber jounce stop from the top of the spring
• Use a sawzall to cut off 3 of the 4 segments
• Use a file to de-burr the hole in the center and any rough edges from the cut
• Put the bag into the spring, fitting side up. Put the (now shortened) jounce stop back in the top of the spring
• Run the air lines from somewhere in the cabin (or wherever you want to mount a compressor or just the tire/schraeder valve) along the frame and zip tie them securely.
• Feed the air lines over the top of the spring perch and down into the spring area.
• Reinstall the springs. As you do, feed the air line through the center hole in the jounce stop and push it into the fitting in the air bag
• Inflate the bags and make sure they don't leak

If you're close to Slee and they can do it, I would take it there because they are trustworthy. If you're not, but you have a reputable local mechanic who is willing to give it a shot, there's a video at LandCruiser - Firestone coil-rite airbags - Project 200 which shows how to do this. Honestly the hardest part IMO is getting the PS side spring in and out - it's really a 2 person job (one to push down on a ~4' prying bar, the other to slide the spring in or out or to realign the sway bar). I'd offer to help but it's probably not worth the 1,000 mile drive to Chicago for you

One note is that the Firestone kit comes with two separate schraeder valves (one per bag). I bought a small compressor for $100 and installed it where my jack was. Because that only has one output line, I bought a T fitting (Amazon product ASIN B001F532PY) to tie them together. If you search around online there are mixed feeling about linking both air bags to one compressor (some people prefer it because it ensures the pressure is balanced, some dislike it because it's harder to isolate a leak or might result in odd handling as air transfers between bags. Personally I've found it takes 30 seconds or so to deflate these so I don't think the small tube lets a significant amount of air pressure move between either bag while bouncing around).

This is my install:

 

[indycole]

The first thing I would double-check is how many segments of the bump stop were cut...

 

[linuxgod]

Does that firestone kit come with 10" or 11" tall bags? I can't remember the model mapping.

Do you have a lift?

10" bags & no lift, cut off 4 bump stop rings
10" bag & 1" lift (i.e. Tough Dog standard duty) cut off 3 rings
11" bag & no lift will not work.
11" bag & 1" lift cut off 4 rings

 

[Sandroad]

For reference, my otherwise stock truck but with the Ride-Rite bags at 5 psi in the rear give me 21 3/4" from the center of the wheel to the lip of the fender directly above. I lost my piece of paper with before/after numbers from 2 years ago when I installed mine, but it was definitely not 2" of lift! It is a small "lift", but I'd be surprised if it's an inch.

On another thought......I can't tell for sure where your fill valves are, but if they are facing down make sure they are well sealed with the cap. Otherwise the caps will fill with water and corrode the valve stems. (Learned the hard way on mine).

 

[swatski]

Does that firestone kit come with 10" or 11" tall bags? I can't remember the model mapping.

Do you have a lift?

10" bags & no lift, cut off 4 bump stop rings
10" bag & 1" lift (i.e. Tough Dog standard duty) cut off 3 rings
11" bag & no lift will not work.
11" bag & 1" lift cut off 4 rings

This is VERY helpful! @linuxgod Thank you for prompt advice, much appreciated!
No lift, my truck is basically stock (other than wheels are powdercoated black,lol)

I'll double check with the guys who did the install, it is a first class shop and they already said to bring the truck back if it stays high, they will look into it. They know @linuxgod posts and the install thread, but if they cut 3 segments - that would be an issue. However, I also noticed the bags were still pressurized this afternoon (afetr my trip back home from work) - and after I thought all the air was out... so, still released a bunch of air. Will go remeasure, and will find see tomorrow morning - if I can fit in my bloody parking garage...

Thank you!

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[swatski]

For reference, my otherwise stock truck but with the Ride-Rite bags at 5 psi in the rear give me 21 3/4" from the center of the wheel to the lip of the fender directly above. I lost my piece of paper with before/after numbers from 2 years ago when I installed mine, but it was definitely not 2" of lift! It is a small "lift", but I'd be surprised if it's an inch.

On another thought......I can't tell for sure where your fill valves are, but if they are facing down make sure they are well sealed with the cap. Otherwise the caps will fill with water and corrode the valve stems. (Learned the hard way on mine).

Okay, that is helpful, thank you! I just ran out and measured this height - I'm at about 22"! This is after I released some leftover air so the bags were not empty, were still pressurized after I did a bunch of driving today.
If I have it right, I might have dropped almost an inch compared to what I saw yesterday (with partially filled bags, I guess) albeit I seem to see 1/2" difference between rides anyway.
I also need to to double check the shop removed all 4 segments, per @linuxgod.
Thank you!

EDIT: Thank you for the tip about the valves, yes mine are mounted at the bottom brace of the rear bumper, no T-tie, two separate valves with those nippy white covers (in pics above). I will put some grease on those valves.

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[JohnPW]

I had the same airbags installed in my 2016, and it raised the rear @1/2" to 1" with 5psi in the bags. It was motivation to install the OEM coil spacers in the front. With the spacers installed there is only a slight rake to the truck.

 

[swatski]

Quick update, after a couple days of riding on "empty" (depressurized) bags I seem to be back to the truck's regular height, measuring slightly below 22", somewhere around 21 3/4" (from the center of the wheel to the fender's lip) - so all is good!

I do not have a pressure gauge that would seem reliable to as low as 5psi, so I think I'm going to leave the bags alone and not worry about a possibility of "pinching".

EDIT: As a side note, I'm very happy to have found M.T. Schiele on Watson in St. Louis, MO. I'll be taking my business there for sure, it's a great shop - like you guys have said. Quick, extremely responsive, and very reasonably priced! And the guys ARE passionate about 4 wheeling Yotas, that's for sure.

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