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  1. Vehicle Suspension
  2. Firestone
  3. Air Springs
  4. Towing/Load Leveling
  5. Rear Axle Suspension Enhancement
  6. Light Duty
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2005 Ford Explorer
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Firestone

Firestone Coil-Rite Air Helper Springs - Rear Axle

Part Number: F4134
In Stock
$139.78
Retail:$208.83
You Save: $69.05
Vehicle Suspension
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2005 Ford Explorer

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For safety and stability, air springs are the perfect partner for your rear suspension when you are hauling heavy loads. Springs fit inside existing coil springs to help level your vehicle, improve braking and handling, and reduce tire wear. Great Prices for the best vehicle suspension from Firestone. Firestone Coil-Rite Air Helper Springs - Rear Axle part number F4134 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (762)
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  • Videos (2)
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Firestone Vehicle Suspension - F4134

Highlights

  • Custom Fit for Your Vehicle: Mounts to existing attachment points
  • 1,000-lb Load Support: Levels your vehicle to prevent rear-end sag and improve handling when hauling.
  • Steadier Steering and Braking: Keeps suspension balanced so braking and control stay consistent.
  • Adjustable Air Pressure (5–35 psi): Fine-tune for heavy or uneven loads to maintain a smooth ride.
  • Prevents Bottoming Out: Adds cushion inside coil springs to absorb road shock under load.
  • Durable Polyurethane Construction: Provides long-term reliability for daily or heavy-use conditions.
Made in USA

Features to know about

Stay Level and Confident: Load-Leveling Support up to 1,000 lbs

When your rear suspension starts to sag under heavy loads, these Coil-Rite air springs step in to keep things level. Working with your existing coil springs, they add up to 1,000 lbs of load-leveling support so your ride height stays even when the bed’s full or a trailer’s hooked up. Keeping the vehicle level means better steering response, balanced braking, and headlight beams that stay aimed where they should.

Smooth Out Rough Roads: Air Pressure Adjustable from 5 psi to 35 psi

Not every haul is the same, and that’s where adjustable air pressure makes a real difference. These air springs let you fine-tune support from 5 psi up to 35 psi, so you can dial in stability for a heavy load or ease it off for everyday driving. Because each side adjusts independently with its own inflation valve, you can correct off-center loads to reduce body roll and keep the ride smooth and steady.

Keep Tires on the Ground and Handing Predictable: Helper Support Inside Your Coil Springs

By fitting directly inside your factory coil springs, this setup boosts suspension performance without changing your ride height or geometry. The added cushion helps reduce tire wear by keeping even contact with the road, especially when towing or hauling uneven loads. You’ll feel more control through the wheel with less bounce and sway when the pavement gets rough.

Built to Last Through Real Work: Durable Polyurethane Construction

These air bags are made from elastic polyurethane that flexes with your suspension instead of fighting it. That durable material holds up under heavy use and rough conditions while keeping its shape for consistent performance. Each kit includes the air springs, hardware, air line, and separate valves for manual inflation—everything needed to get up and running with dependable support for years of use.

Specs

Weight and Capacity

  • Load-leveling capacity: at least 500 lbs (at most 1,000 lbs)

Adjustability

  • Adjustable air pressure: 5 psi to 35 psi

Firestone Coil-Rite Air Helper Springs airline installation diagram showing tubing routed for manual inflation valve access at vehicle bumper

Warranty

  • Air springs: Limited lifetime warranty
  • Hardware: 2-Year limited warranty

Note

The construction material of the fittings may vary.

Firestone Coil-Rite Air Helper Spring kit components including air springs, brackets, tubing, and installation hardware for rear axle suspension enhancement

W237604134 Firestone Coil Rite Air Bags - Suspension Kit - Rear Axle

4134

Installation Details F4134 Installation instructions

This Product Fits The Following Vehicles




Video of Firestone Coil-Rite Air Helper Springs - Rear Axle
Video Thumbnail Video Player Dialog

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Checking Out the Firestone Coil-Rite Air Helper Springs

Today we're going to be taking a look at the Firestone coil rite line of air helper springs. Be sure to see eTrailer's fit guide for your application.Our springs are designed for a wide variety of vehicles. They're going to fit most passenger vehicles, vans, some light duty pickup trucks and motor homes. Whenever you haul a heavy load, have a lot of equipment in your vehicle or have a heavy trailer hooked up to it, it's going to cause the back end to sag down which is putting a lot of strain on your rear suspension, not to mention you're taking the contact off the front tires and misalignment your headlights. Our coil rite springs are going to take a lot of that effect out and help the sag in the rear end.Your air springs may look a little bit different than we have here, so you want to make sure you check each other's fit guide for your specific application, but these are going to provide us a smoother ride for vehicles that have coil springs in the back. They're designed to fit inside the spring, which is going to create a variable spring rate and help prevent the sag when we're loaded down and take stress off the rear suspension.

Our springs are going to be made out of a polyurethane, so they're going to be durable and last a long time. They are rated for working in temperatures from negative 40 degrees Fahrenheit all the way up to 180 degrees Fahrenheit. Each set is designed to support 500 to 1000 pounds and having an operating range of five PSI all the way up to 35 PSI.One thing I do want to mention is that our coil rite springs are not going to increase the payload of our vehicle. They're just there to help support the extra weight. So you always want to double check your vehicle's owner's manual and never exceed the manufacturer's recommended weight.Compared to other style of EHRs springs these are specifically made for the coil spring suspension, opposed to the leaf spring where that would sit on top.

These are gonna help out a lot with the SAG and prevent bottoming out and give us a smoother ride even when we're unloaded.Our kit's gonna come with two manual inflation valves. That way the bags can work independently from each other so we can inflate each one to our desired amount. That's going to help a lot with those off center loads, or if we take an evasive maneuver, it's going to take out some of that body roll. Our helper spring kits is going to come with everything you need to get it installed. Both springs, any brackets necessary, the lines, and the inflation valves.Ryan wrote in saying the install was easy on his 2014 FJ cruiser.

A year later he wrote back in and saying after a year of regular use, the bags had been great. They keep as FJ level where he's towing, and as a result, the steering while towing is vastly better.If you've had the back end of your vehicle sag down, rough ride, uneven tire wear, or even misaligned headlights our coil rite springs are going to help out a lot. All while giving us a smoother ride.

Customer Satisfaction Score:

Ratings & Reviews

4.4

762 reviews
Review sort icon
For safety and stability, air springs are the perfect partner for your rear suspension when you are hauling heavy loads. Springs fit inside existing coil springs to help level your vehicle, improve braking and handling, and reduce tire wear.

by:

I learned the hard way that towing with independent rear suspension ends up wearing out the inside edge of the rear tires due to the sag changing the toe-in of the rear tires. I purchased these to raise up the back end when towing. Just finished installing. Went smoothly. I may have missed it in the directions, but on my RAV4, the upper coil spring bumper (They call it the upper protector) can be installed up thru the bottom support of the coil spring. I tried unsuccessfully to slip it between coil springs. It would not fit. It was a bear slipping the collapsed air spring between the coil springs. But with the aid of a very blunt tire iron, it went fairly quickly. Thumbs up so far. Time will tell if tire wear goes away, but I'm sure this will help. Thank You!



by:

I've yet to install these, I will update once complete. But I've heard from numerous people that if you life the van at the jackpot and let the weight of the tire extend the spring, you can remove the stopper with channel locks and slide the bag in using a liberal amount of soap, so you don't need to disassemble the axle. Again, I will update when completed.



by:

THE SERVICE IS AMAZING IHAD A SMALL ISSUE AND IT WAS HANGELED BY PAULA IMEDIATELY THANK YOU THE PRODUCT IS INSTALLED ON A 2014 VW BEETLE THERE IS A HOLE IN THE BOTTOM OF THE SPRING HOLDER SO I INSTALLED THE AIR SPRING WITH THE LINE AT THE BOTT0M AND THREADED THE LINE STRAIGHT OUT THE HOLE PRETTY SMOOTH THANKS AGAIN



by:

my air bags for my 23 ram were easy to install, the service was excellent. I will be telling every body I know about how friendly and easy it was to order from you.



by:

Worked well. Second time I’ve installed them on a 4Runner. The result was a needed improvement in sway, dive and sag. It also helps the steering wander.



by:

Great upgrade for carrying weight in the back or towing a trailer. They are a bit tough to install. I found twisting the bag over in the middle and inserting it between the spring to the trick. Insert the top side on the passenger bag first. Insert the bottom side first on the driver side take care with the week ass tubing because if it folds over on itself in a coil, it will remain pinched which I can see will cause problems in the future. The tubing was better 20 years ago than what they give you today. One tube replacement over $30!! Ridiculous !! I like the right height adjustability and my truck feels more stable with a load of weight in the back of my truck advertised in the video shown below.



by:

Firestone airbags have worked well for my 2017 4Runner. When I'm not attached to my camper, I keep the airbags deflated to about 5 PSI. But when I put my trailer 3,500 lb. Onto the back of my 4Runner I get several in of sag. I pump up the airbags to about 20 psi and I level out the whole rig. What a perfect hybrid system to have. It's there when you need it. Perfect system for a sagging. Backside on a rear coil spring 4Runner. Thanks, e-trailer



by:

These were just as described as far as quality and look. The installation of them were a little more difficult than they show in the video but can easily be done by someone with basic skills. I would recommend if you have the ability to remove the springs and then just insert the bags that way as I couldn’t get one in without doing that. Otherwise the install is pretty straightforward. Haven’t used them with a load or towing yet but hopefully they will work as designed.



by:

Parts are very good quality but installation instructions for my 14 Jetta were very poor. Had to air to 25 psi to keep air bag from shifting in spring but did help stabilize vehicle.



by:

It fit great. And works like a champ... I couldn't be happier with these air helper springs! E trailer made it easy and they followed up with me to make sure i'm pleased with the product... Very happy with the service.



by:

Great product. I must say that they were a little tough to install. A very tight fit. Fortunately for me I had the availability of a vacuum pump. With that I was able to evacuate all the air out of the bags which made them flatter, with that, it made it easier to slide them between the coil springs. I tow a small camper trailer, I usually run around 20 psi in the bags. This keeps my vehicle level and adds for a smooth ride. A great product.



by:

I initially ordered the wrong airbags. I called eTrailer and Jeremy H. was very understanding. He got the right ones immediately shipped out and sent me a return label and info while I was on the phone with him. The bags seem good quality comparable to my previous Airlift bags. Instructions were well written and all hardware was accounted for in the shipment.



by:

Easy install on lc200, it’s only been a couple days but test run with a trailer was great. Recommend getting getting inflation bracket (Firestone WR17607560) to reduce the need for any drilling if you don’t go with onboard compressor.



by:

The airbags were difficult to install on a 2021 Sienna. It required removing the rubber stopper from inside the coil spring. Once that was out, install was easy. However, these need to be installed with the valve down as the plastic spacers fall out when the van is lifted for service when installed right side up as recommended. Upside down the air hose is routed thru the center of the plastic donut spacer which holds it in place when the van is lifted. However, once installed "upside down" the valves tend to pinch on the suspension as they move around. The pinching lets the air out and requires the bags to be frequently repositioned especially after the van is lifted for service. It is a good product, just unreliable and requires much inspection and maintenance to work properly. Will be loading up again for a summer trip and will need to reposition them so they work as I just had the oil changed.



by:

These bags along with minor adjustments to my load leveling hitch made towing my 19.4 No Bo trailer so much more relaxing!I am running 20 PSI and 3/4 of an inch higher than stock ride hight. Easy peasy



by:

I bought this set because I was having problems with one of the airbags I previously had gotten. It was on the right side of my forerunner. It had a slow leak. When I replaced the airbag this time it had a very fast leak. I finally found That if I used NAPA Sil-Glyde to insert tube it seems to be holding air. And I squeezed air bag into the spring. Use soap for sliding it in.



by:

Phone service was excellent. Air bags helped a lot with stability. I found it easier to remove the spring from the Avalanche than to fight with it in chassis. Removing the spring also gave me a chance to clean the dirt and rocks out of the hose routing area. It was a little more work to drop the axle down but it really wasn't that bad. I was able to do it all without a hoist. Just used two floor jacks. I just let one side down at a time. Remove your swaybar link and shock and let one side down. Pull the spring and do the work in a vise. Its much easier than fighting with it on your back. Also put the air hose in really hot water and it will relax its memory.



by:

Installer couldn't get them to hold air for more than a day.
And if pressure falls below 5 psi, there's a risk of damaging them.
Installation was difficult.
But they do fix the ride height issue when towing.
If I had it to do over, I'd get Sumo springs.



by:

Well I did not expect to have a one year follow up from ETrailer! I’m a 5 Star happy with these airbags over the AirLift 1000’s I had that blew out just after the warranty was up! These bags are more than twice the product, as you can inflate to >60 psi and that makes for a way more steady ride with weight! I typically run mine at around 45 psi now, the AirLift are limited to 28 psi. The construction is far superior and quality is excellent!!!



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by:

Had trouble getting them not to leak off finally think. I’ve got it.also I am having a problem trying to get them set where they.need to be when towing my rv. But I believe Iam making progress



by:

works very well, improved the ride on my truck towing or not! buy the tubing cutter. you must have straight cuts. other wise easy install.



by:

Very fast delivery! Great Prices! These were a snap to install (less than an hour) and worked perfectly to level truck/trailer. Already ordered from them again and will continue too anytime I need something. Thanks ETRAILER!

Auguat profile picture

Auguat

4/17/2013

Well.... right bag blew after one week. will contact etrailer on warrenty.... Might switch to rubber snubbers and leveling hitch instead. May have just got a bad one........

Patrick B. profile picture

Patrick B.

4/25/2013

Thanks for the follow up. I see that you went with the Timbren kit instead, please let us know how you like it.


by:

Fit my 2001 Expedition perfectly. Took away all the sag when towing and like others have said I like the way it rides better even unloaded with 5PSI in the bags. Well worth the money, easy install. FYI this was my first time using bags on any vehicle, I was nervous and these were fabtastic!

Heather A. profile picture
Etrailer Expert

Heather A.

4/11/2026

That’s awesome to hear, especially for your first time running air bags. Sounds like they did exactly what you were hoping for. Getting rid of that sag makes a huge difference when towing, and once people use air bags, they usually don’t go back to those dense rubber suspension springs because the ride unloaded is so rough. Glad the install went smooth for you as well. That’s a solid upgrade on an Expedition. What are you usually towing with it?


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See what our Experts say about this Firestone Vehicle Suspension

  • Coil Spring Air Bag Kit Comparison for a 1997 Ford Expedition 4WD
    The Firestone Coil-Rite Air Helper Springs, # F4134 and the AirLift 1000 Air Helper Springs, # AL61792, are essentially the same product. The main differences between the two kits are the included parts. Both kits come with everything needed to complete the installation, but the Airlift 1000 kit includes two additional round air bag supports for the top of the bag. The Coil-Rite kit provides bag supports for the bottom of the bag only. I have attached the installation instructions for...
    view full answer...
  • Installation Information For Firestone Coil-Rite Air Helper Springs # F4134 on 1999 Ford Expedition
    You will not need to remove the springs on your 1999 Ford Expedition in order to install the Firestone Coil-Rite Air Helper Springs # F4134. You will insert the deflated air bags into the coiled springs from the bottom as shown in the graphic I have provided. I have also provided a link to the full installation instructions for this product. These air springs will help reduce tire wear but will not increase your vehicles weight-carrying capacity. The weight capacity of these springs are...
    view full answer...
    Image 1 for
  • Air Bag Suspension System and Air Compressor for a 1999 Ford F-350
    Sorry you weren't able to find that old question. For your 1999 Ford F-350 I recommend the Air Lift LoadLifter 5000 Ultimate Air Helper Springs with Internal Jounce Bumpers item # AL88390. These have a 5,000-lb weight capacity they will work well with a weight distribution system to keep your truck level. The air bags reduce the strain on your rear suspension, increase safety, and compensate for uneven loads. They level your truck from front to back and adjust independently for side-to-side...
    view full answer...


Info for this part was:

Employee Leah B
Updated by:
Leah B
Employee Mary K
Updated by:
Mary K
Employee Wilson B
Updated by:
Wilson B
Employee Daron K
Updated by:
Daron K
Employee Alex H
Updated by:
Alex H
Employee Tyler C
Written by:
Tyler C
Employee Jacob T
Video Edited:
Jacob T
Employee Chris R
Video Edited:
Chris R
Employee John H
Expert Research:
John H
Employee Brandon M
Expert Research:
Brandon M
Employee Jonathan Y
Video by:
Jonathan Y
Employee Robert C
Installed by:
Robert C

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