Removing air suspension, replacing with coils

[Egan]

Replacing the H2 air suspension with coil springs:

This is actually a really straightforward project and should only take an hour or so. This eliminates the sagging in the rear end when the air system leaks, because, well, there is no more air to leak! The parts can be had from gmpartsdirect.com:

Left coil: 25956182
Right coil: 25956183
Spacers (x4): 15713853

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01951.jpg

Step 1: Remove the rear wheels (will make your life easier) and get the H2 up in the air. Then support the rear end. You?re going to disconnect the rear end and axle from the suspension so without support it will fall to the floor!

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01944.jpg

[Egan]

Step 2: Disconnect the shock and swaybar from the axle. For the shocks, remove the bolts at the bottom. For the swaybars, it will be easier to remove the bolt up top.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01945.jpg

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01946.jpg

Step 3: Lift the rest of the truck off the axle and/or lower the axle.

Step 4: Next I went after the air system itself, dropping the compressor and tank, disconnecting the wires, and cutting the airline feeds to both airbags as well as the tire inflator in the bed.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01947.jpg

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01948.jpg

I just taped up the wiring harness and zip-tied it up under the bumper.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01949.jpg

[Egan]

Step 5: Now take out the airbags. Simply turn clockwise and they will come free.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01950.jpg

You should also remove the spacers the airbags rested on.

Step 6: Install the bottom spacers, install the coil springs with the top spacers on them, and then lower the H2/raise the axle.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01952.jpg


Step 7: Reconnect the shock and swaybar bolts. 77 ft-lbs for the lower shock bolt, 53 ft-lbs for the swaybar bolt.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01953.jpg

[Egan]

Finished product:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01954.jpg

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01955.jpg

Once it settles in, I may have to raise the front end at the keys to level it out.

[HummerJim]

Nice write-up!! Well done!!

[VegasGuy]

I agree. Great write up and excellent pics, Egan. Kudos!

[pdxrealtor]

Great info! Thanks!

Is it possible to keep the compressor operational? A few uses for air a side from the suspension. Even though it is a week compressor system....

[Egan]

Great info! Thanks!

Is it possible to keep the compressor operational? A few uses for air a side from the suspension. Even though it is a week compressor system....

You could keep it in although I think it is controlled off the level sensors and switch in the cab. It probably weighs 30 lbs so I tore it out. I'm going to use the mount the compressors were on to mount my air horns, tank, and compressor. I'm going to see if I can tee the bed inflator port into the air line off the tank. But that write-up is for next weekend. :)

[fyr145]

Thats what I was wondering, I have the spring set up but got the compressor to have on board in case I needed air for my tires or any other inflatable goodies and just use it for that alone.

Egan,

If you arent going to use your old harness, is there anyway that I could get it from you so I could use it for this purpose?

fyr145

[Egan]

Thats what I was wondering, I have the spring set up but got the compressor to have on board in case I needed air for my tires or any other inflatable goodies and just use it for that alone.

Egan,

If you arent going to use your old harness, is there anyway that I could get it from you so I could use it for this purpose?

fyr145

It looks like the wiring on the truck joins up with a much larger wiring loom at the bumper and then runs to the front of the H2. Pulling out just the air controls may be difficult. As for the wiring at the compressor end, I have it all pulled apart and you're welcome to any of it.

In fact, if anyone needs spare parts (compressor x2, tank, airbags x2) let me know.

[RJ03]

How much would you want for the air compressor assembly? Thanks, RJ

[Easy Ed]

Pulled all mine out in 2007 :D

http://www.elcovaforums.com/forums/attachment.php?attachmentid=36217&stc=1&d=1171244765

Link to post http://www.elcovaforums.com/forums/showthread.php?t=24471

[fyr145]

It looks like the wiring on the truck joins up with a much larger wiring loom at the bumper and then runs to the front of the H2. Pulling out just the air controls may be difficult. As for the wiring at the compressor end, I have it all pulled apart and you're welcome to any of it.

In fact, if anyone needs spare parts (compressor x2, tank, airbags x2) let me know.

I need the wiring at the compressor end that it plugs into. It looks like is a 24 pin connection and theres another smaller 2 pin connector near it as well. You show it in one of your pics that says you zip tied it to the rear bumper.

Do you still have the bolts to the compressor too, so that I can get mine mounted?

Let me how much shipping is and I can send you payment via Paypal.

Thx,

fyr145

[Joe]

I'd be interested in your ride height sensors (both sides) if they are good and not broken (which looking at how clean your under carriage is I guess they are perfect :) ).

Just PM me if interested w.price

Thanks

[Egan]

I need the wiring at the compressor end that it plugs into. It looks like is a 24 pin connection and theres another smaller 2 pin connector near it as well. You show it in one of your pics that says you zip tied it to the rear bumper.

Do you still have the bolts to the compressor too, so that I can get mine mounted?

Let me how much shipping is and I can send you payment via Paypal.

Thx,

fyr145

If you need the wiring that goes from the harness I tied up under the bumper to the compressor & solenoid, I have that. I also have the nuts and bolts for the compressors (nuts&bolts for the front of each, nut only for the rear - there are studs built into the mounting plate).

Keep in mind that this is the 2 compressor setup.

Send me a PM with your zip and I'll get a freight quote.

[Egan]

I'd be interested in your ride height sensors (both sides) if they are good and not broken (which looking at how clean your under carriage is I guess they are perfect :) ).

Just PM me if interested w.price

Thanks

I left these in place, so let me see if I can pull them out tomorrow. I'll check the service manual, but do you have a picture of what they look like / where they are.

[Joe]

If you look inside rear wheel wells towards front of truck you should see them. Looks like a little piston like thing attached to rear suspension and connected with a cable/plug. Mine are covered with an undercoating from previous owner but I think they simply bolt in with one or two bolts. I don't necessarily need the wiring harness from the sensors back but if you find its easy to take that out as well i'd be interested in it as well. Really just need the sensors themselves though.

[fyr145]

If you need the wiring that goes from the harness I tied up under the bumper to the compressor & solenoid, I have that. I also have the nuts and bolts for the compressors (nuts&bolts for the front of each, nut only for the rear - there are studs built into the mounting plate).

Keep in mind that this is the 2 compressor setup.

Send me a PM with your zip and I'll get a freight quote.


PM sent

[Egan]

If you look inside rear wheel wells towards front of truck you should see them. Looks like a little piston like thing attached to rear suspension and connected with a cable/plug. Mine are covered with an undercoating from previous owner but I think they simply bolt in with one or two bolts. I don't necessarily need the wiring harness from the sensors back but if you find its easy to take that out as well i'd be interested in it as well. Really just need the sensors themselves though.

Got it. I'll take a look tomorrow when I have the truck back up in the air.

[Egan]

If you look inside rear wheel wells towards front of truck you should see them. Looks like a little piston like thing attached to rear suspension and connected with a cable/plug. Mine are covered with an undercoating from previous owner but I think they simply bolt in with one or two bolts. I don't necessarily need the wiring harness from the sensors back but if you find its easy to take that out as well i'd be interested in it as well. Really just need the sensors themselves though.

I found them no problem, but I read that if I take them out I'll get a trouble light on the dash. Is there a way to avoid this?

[Joe]

I found them no problem, but I read that if I take them out I'll get a trouble light on the dash. Is there a way to avoid this?


I'll be honest, I'm not sure. I think since you pulled the compressor and don't plan to use you may be able to pull the fuse and recycle the power to clear the Service Air Suspension you will get when the sensors are removed. I think once cleared it won't come back.

Probably best to see if someone who has done this already can answer the question.

[USMC_Buckaroo]

Howdy Egan,

'Boy Howdy' was that a great post!!! :perfect10s:

I have been babying and milkin' my '03 for months, attempting to figure out how best to extend the life of the rear air suspension system. Figured out for a while that if I left the door ajar {in my driveway} the bags wouldn't deflate {worked for a while} Tried several other gyrations until the compressors finally gave out.

I'm retired and pushin' 60 so wasn't excited about jumping under a vehicle again but...after reading your article and how easy you made it seem, I think I'm gonna 'Cowboy Up' and do it myself!

I really want to thank you for taking the time to post that wee tutorial, it really ABC'd me and pushed me into taking the project on...again, Thanks!



Buck.

[pdxrealtor]

Anyone know how to get the 'service air suspension code' off the dash, after removing the height sensors and compressor?

[USMC_Buckaroo]

Bump!


I'm interested in the potential answer to this as well.......




TIA.




Buck. :D

[USMC_Buckaroo]

Howdy All,


Further, I was hoping to get some friendly feedback from the great members here on this particular set of rear coil springs....
http://ecx.images-amazon.com/images/I/51Y5KHhqAkL._SS500_.jpg
http://www.amazon.com/Hummer-Rear-Suspension-Spring-Conversion/dp/B009K2FWGQ


Their Amazon 'Storefront'
http://www.amazon.com/gp/browse.html?ie=UTF8&marketplaceID=ATVPDKIKX0DER&me=A2E9UMXG1PX9OB



Thanks in advance!



Buck. :D

[iwillnc]

To get rid of service message take it to HUMMER to have them reprogram the ecm

[pdxrealtor]

To get rid of service message take it to HUMMER to have them reprogram the ecm

Actually, it does not. Maybe I got lucky, but after a program, revert to OEM, and program I no longer receive the air suspension message. It's been at least a month.

Note I've also run the battery dead for two days, yet no error message.

[suesue10]

Can anyone tell me if it rides better or worse with the coils??? I have an 03' with a "service air suspension" and the garage says he thinks its the sensor but no way to tell for sure. A new sensor is 500 bucks and I can get the whole coil set up for that, but I'm worried it will ride really stiff. Any feed back would be greatly appreciated! I also need a new exhaust for it but can't seem to find a stock exhaust for a hummer. It has a flow master now and its pretty pricey to replace.

[Egan]

Can anyone tell me if it rides better or worse with the coils??? I have an 03' with a "service air suspension" and the garage says he thinks its the sensor but no way to tell for sure. A new sensor is 500 bucks and I can get the whole coil set up for that, but I'm worried it will ride really stiff. Any feed back would be greatly appreciated! I also need a new exhaust for it but can't seem to find a stock exhaust for a hummer. It has a flow master now and its pretty pricey to replace.

I noticed very little difference, if any, after switching to coils.

[suesue10]

Thanks egan... Seems better long term to change them to coils.. If I don't next will be the bags or compressor..

[fyr145]

While the coils may not offer a better "ride", they do offer less maintenance of the rear suspension system overall. To stay with the air bags and compressor means to have to guard against eventual air bag leaks, sensor malfunctions, and compressor burnout.

For the cost of the springs to be purchased and installed, seems to me you'd be much better off with the coils and not the older air system......just my .02.

fyr145

[USMC_Buckaroo]

Guess I'll figure it out myself...thanks anyway.



Buck.

[fyr145]

Guess I'll figure it out myself...thanks anyway.



Buck.


Buck,

What was it you were looking for???

[Easy Ed]

As long as the springs each have a different part number or they are a "set" and state right and left and you get the four rubber pcs. go for it.

I went with OEM springs and there is a difference between the two.

Some info links below, good luck, Ed

http://www.elcovaforums.com/forums/showthread.php?t=40631

http://www.elcovaforums.com/forums/showthread.php?t=24471

http://www.elcovaforums.com/forums/showthread.php?t=38979


Howdy All,


Further, I was hoping to get some friendly feedback from the great members here on this particular set of rear coil springs....
http://ecx.images-amazon.com/images/I/51Y5KHhqAkL._SS500_.jpg
http://www.amazon.com/Hummer-Rear-Suspension-Spring-Conversion/dp/B009K2FWGQ


Their Amazon 'Storefront'
http://www.amazon.com/gp/browse.html?ie=UTF8&marketplaceID=ATVPDKIKX0DER&me=A2E9UMXG1PX9OB



Thanks in advance!



Buck. :D

[USMC_Buckaroo]

Howdy Easy Ed,

Mucho thanks for reaching out a helping hand pard', and providing those links. :beerchug:

In one of them you said " pulled the compressor and leveling sensors out completly "...I don't suppose a more detailed description of precisely how you do this exists anywhere? I'm recently retired from the home building trades and could easily design/build you your own personal cathedral, but, it's been MANY years since my days of tinkering with race cars and hot rods....heck, the only mechanical tools I own are a set of Husky brand sockets my kind wife bought me for Christmas. Sufficient for household undertakings but for anything more than that they are :lame:


Buck.

[Easy Ed]

Sorry Buck but all the stuff that I removed is not something I would recommend to anyone unless they really feel comfortable in doing so and also sorry to say there is no detailed "how to" to remove it all, I just got crazy in removing mine as seen in the pic's cause it pissed me off for the last time ;)

Pulling the compressor is not hard, few bolts and electrical connectors and hoses to the bags, rest of the replacement is in the links. Anything left in the way of wiring harness to the compressor and to the sensors can be wire tied up. Removing the relay up on the front frame rail along with disconnecting the battery for a few may prevent the "Service Suspension" light from coming on.

Best of luck, Ed



Howdy Easy Ed,

Mucho thanks for reaching out a helping hand pard', and providing those links. :beerchug:

In one of them you said " pulled the compressor and leveling sensors out completly "...I don't suppose a more detailed description of precisely how you do this exists anywhere? I'm recently retired from the home building trades and could easily design/build you your own personal cathedral, but, it's been MANY years since my days of tinkering with race cars and hot rods....heck, the only mechanical tools I own are a set of Husky brand sockets my kind wife bought me for Christmas. Sufficient for household undertakings but for anything more than that they are :lame:


Buck.

[USMC_Buckaroo]

Howdy Ed,

Again, thanks for the advice. :)

I just now ordered those specific part #'s from gmpartsdirect.com that Egan listed in his original post...guess I'll just have to cross my fingers and 'soldier thru' any difficulties.

I don't suppose anybody knows/remembers exactly what size the bolt/nuts were that our good Egan mentioned...? " For the shocks, remove the bolts at the bottom. For the swaybars, it will be easier to remove the bolt up top " I'll be taking it to one of those DIY shops ( Don't Laugh!) where you can either do it yourself, have them help, or let them do it for you, and just wanted to make sure I brought the correct tools with me (to potentially lessen the 'chuckle' factor).


Thanks in advance for any help.



Regards,

Buck.

[Easy Ed]

Buck, Even though it is kinda cold out here in Ohio I went on out to the garage crawled around on the floor :giggling: and check what size sockets you would need for those bolts. The shock bolt takes a 21 mm socket, the upper sway bar bolt takes a 18 mm socket. Might be a good idea to also have box end wrench's in those sizes also to hold the other end of the bolt. (This is on a 2003 and do not know if different on newer models)

Good luck, Ed


Howdy Ed,

Again, thanks for the advice. :)

I just now ordered those specific part #'s from gmpartsdirect.com that Egan listed in his original post...guess I'll just have to cross my fingers and 'soldier thru' any difficulties.

I don't suppose anybody knows/remembers exactly what size the bolt/nuts were that our good Egan mentioned...? " For the shocks, remove the bolts at the bottom. For the swaybars, it will be easier to remove the bolt up top " I'll be taking it to one of those DIY shops ( Don't Laugh!) where you can either do it yourself, have them help, or let them do it for you, and just wanted to make sure I brought the correct tools with me (to potentially lessen the 'chuckle' factor).


Thanks in advance for any help.



Regards,

Buck.

[USMC_Buckaroo]

Ed, you are a Prince!! :perfect10s:


I genuinely appreciate your determined endurance against both the chilly garage floor and the mid-west's piercing cold and send you a Titanic-sized "Thank You!" pard'...... 21mm & 18mm box end wrenches it is!



Buck.

[pdxrealtor]

Just RE-DID my rear springs today. Don't ask!

In any event when installing the OEM rear springs you do have to disconnect the sway bar at the upper mount as mentioned above, AND , you have to get the rear end down low enough to insert the springs. Lower than you have to get it for removing the OEM air bags!

On another note. I STILL have not received an error message on the DIC about the air suspension.

My battery has gone dead for more than 3 days, I've changed batteries, I've gone from lowered to OEM height springs, ............ nothing on the DIC regarding the air suspension.

I'm not sure if installing the custom diablew tune has anything to do with it or if after you re-set a number of times it just goes away but in any event I haven't had the error message in months.

[USMC_Buckaroo]

"...AND , you have to get the rear end down low enough to insert the springs. Lower than you have to get it for removing the OEM air bags!..."



I assumed that would be the case, but thanks for the confirmation...I guess I'll be letting everyone know later on, since TODAY is the day I'll be doin' mine. :raar:



Buck.

[Easy Ed]

How did it go ?

"...AND , you have to get the rear end down low enough to insert the springs. Lower than you have to get it for removing the OEM air bags!..."





I assumed that would be the case, but thanks for the confirmation...I guess I'll be letting everyone know later on, since TODAY is the day I'll be doin' mine. :raar:



Buck.

[USMC_Buckaroo]

Howdy Ed,


"...How did it go?..."

I'm almost ashamed to admit that the whole thing went as smooooth as silk! :excited:

But, as the head mechanic said (funny how the presence of a Hummer in a crowd tends to gather the gearheads...) " Usually the anticipation of doing something, is more stressful than the actual DOING of something"

The DIY shop I went to was fabulous, and having the support at arms length was priceless even though I did all the work myself. Once I got it up on the lift I was entertained to see that the air bags were so completely deflated that they weren't even in contact with the lower seat (axle), but instead were all shriveled up and hangin' by the upper body mounts! Sheeeesh!

All in all, subtracting yakkity-yak time with the other mechanics, I think it took me all of 30-35 minutes. And that included removing the air compressor pan, tie wrapping up all the harnessess, and pulling all of the air lines.


OH!...almost forgot, 1) I didn't need to disconnect the battery cables to allow the system to 'reset'...everything just settled down all by itself with no 'air suspension' warnings.
And 2) I didn't have to remove the height level sensors either. Figured they weren't in my way, and it wasn't really worth the affort if it wasn't going to set off any alarm bells.

Next up, replacement of the driver's side rear window mechanism (recent break-in).



Can't tell ya all how GOOD it is to not be runnin' on the bump stops anymore!


Thanks again for all the sage advice, and the kind encouragement.


Warm regards,


Buck. :beerchug:


PostScript: FYI, I tried to post a couple of photos, but for some reason I can't get ElcovaForum to accept the link addy....

[Easy Ed]

Congrats Buck, Ed :beerchug: