#4051018 - 03/09/20 08:07 AM
Rear Air Suspension Retrofit - by BigPip
3 Orange Whips
Loc: Cleveland, OH
The following article was compiled from various posts by BigPip and can be found HERE.
Thanks to RF_Overlord for recommending this one to the BOK.
I have given it a lot of thought and I believe I can make this work. I had the rear air suspension in both of my Continentals and my Mark VIII and I loved it! About a year ago I picked up a low mileage cream puff and the rear is starting to sag😢.
I first looked at air shocks, work perfect for my truck! Then I came across the airlift 1000 bag you stuff in your coil spring. Pair it up with the gauge, pressure sensor and compressor and your golden.
However, I have gone a step further and thought about installing factory style air bags and and using a kit like the airlift compressor kit but this is where things get complicated. The factory bags have a solenoid attached to them that open and close which means a pressure switch in the line between the bags and compressor will not work. Then I thought maybe an aftermarket level kit to trigger the compressor to fill/purge. I am also leaking towards a factory style compressor also mounted under the hood in factory location under air box. I have studied to Ford Factory Service Manual with the wiring diagram and know that I am not going to use the air suspension computer or levels but I really think I can use the compressor and bags.
I've done some more reading and found that converting to factory RAS is not that hard so that is the route I am going. I already confirmed that the wiring is present for the compressor, the fuse and relay are already wired and installed, and the wiring is already in the cab. The wires come in the car into a plug in passenger for area. I just need to add 3 wires to that plug for the module. I didn't find the 7 wires for the solenoids and hight level unit yet because of a terrible headache- laying on the floor board didn't help so I will attack them later and search for them. Even if I have to run these wires, it will be a walk it the park.
I'm excited to convert to air ride- exciting times
Today I spent some time at the bone yard gathering my parts. I picked up the air hose/line, control module, compressor and all the wiring including the trunk switch. I think the worst part so far is the wiring... only because I didn't bring a blade with me and having to unravel the tape from the trunk to the glove box was a major PITA! nonetheless, I feel pretty good about it now. I already ordered new bags and solenoid valves. Tomorrow I might either run the wiring or air line. Bags won't be in until next week so I figure a couple days to do the install should be a breeze. I will probably run the wiring to get it out of the way.
Time for the wiring, one thing I am going to change is the switch wires run on driver side factory and the other 7 wires for the solenoids and height sensor run on passenger side. I am going to run everything on passenger side. There is also one wire from the switch that splices into the height sensor wire just a few inches from the module- probably because they run on opposite sides of the car- I am going to splice it in in the back of the car.
I am going to install the switch first and work my way around to the plug for the height sensor and solenoids, make my splice and continue to run the wires through the factory jamb wire safe and get everything up front.
Today, I had a little bit of time so I finally got started running the wires. I still need to repin the harnesses to the RAS box but all the wires are ran through the car and under the dash behind the glovebox.
Switch is installed:
Wired soldered back together:
So the wires safe 👍🏼
This box will be replaced with the RAS box very soon
More to come soon. I hope to get the wiring finished tomorrow then I can run the air lines install compressor, pull rear springs and install new bags!
I won't bore you with all the wiring details but I did finally get the wiring complete! De-pinned original plug to repin to the new plugs and ran the wires to the bulkheads under the dash. One bulkhead needed 3 wires and the big bulkhead needed one plugged in and one wire tapped into one of the wires.
Wiring mess: now is a good time to be a soldering junkie
All cleaned up with RAS box installed and all wires wrapped up nice and neat
I took more pictures along the way I can post if any one is interested. If I get a chance tomorrow, I want to run the air hose from front to back and install the compressor. My new bags came in today along with a solenoid which I hope I can install on Thursday but may be Friday depending on how tomorrow goes. I really think the hard part is over with at this point, everything else should really be plug and play.
BigMerc, I get it.... Completely! I loved the air ride I had in my Continental and for people to say it to expensive to replace an air bag and just cut everything out is just stupid. I literally paid $58 for a PAIR of air bags which is a whole lot cheaper then a set of springs. And the air ride is so much nicer!
I did get the compressor and air hose installed today! The compressor wire harness was already wired in behind the windshield fluid bottle:
Here it is all bolted in, holes were already there
I didn't take any pictures installing the air hose, that's just one of those things that was a little but trickier than I wanted since I was working with the whole line front to back. My advice would be start in the left rear wheel well with the tire removed and push the house through there. You can run the section that goes over the the sub frame and then run the forward section through.
TOMORROW... I get to install the air bags and flip the switch. So exciting!
The final piece of the puzzle is heat/header wrap on the exhaust pipes closest to the bags. I should be receiving it tomorrow. I hope it comes early because I believe it will be easier to wrap with the bags off.
That's all I got for tonight.
Nevermind about the level thing, I was looking at the passenger side, once I slide to the driver side it all made sense again...
This was about easy step, holes were already there. Now The Excitement Gets Intense... Time for the bags
Awesomeness! Fired her up and noticed the light was working, good to know that got wired in correctly
Rear is sitting a little... Okay maybe A lot higher. Almost 2 inches, I pulled the whole level sensor and brackets off a Town Car so my thought is maybe their brackets are different??
Either way- total win! I installed a Ford Factory RAS in a car not originally installed on and it works and functions! Level sensor is mine detail that will be worked out.
In case anyone is interested in cost break down, here it goes.
Air compressor, air hose, one solenoid, rear switch,RAS module and all wiring were picked up at the junkyard for a solid $100
Rear airbags from Amazon were $58 for the pair, one solenoid was $24 from Amazon and the exhaust wrap was air $20 from Amazon. So just a touch over $200 and I couldn't be happier. Of course, none of this would have been possible without the Ford Factory Service Manual, I picked the complete 3 book set off eBay for about $40 I think last year.
So I figured out why it was so high, I had the bottom bracket booked on upside-down which in turn means- for those of you who want to lift you air ride cars- I had at least a 3 inch lift by having that bracket upside-down. And I had it all the way outboard which is to lower, bring it inboard to raise it up.
I would say I feel like an idiot for that small mishap but honestly I don't, the Ford manual doesn't show a good representation of it installed and when I pulled it at the boneyard, I just removed it so take it from me- take pictures...
Anyways, factory RAS CONVERSION is complete. Front wheel well height matches rear wheel well height.
'91 LTD Country Squire (POTM Mar. '19) | '03 Marauder (POTM Nov. '10, Jul. '20) | 2010 P7B (POTM Feb. '21) formerly: '02 MGM, '04 MGM, '04 MGM v2.0, '04 MM, '07 P71 (POTM Feb. '18), '04 CVLX (POTM Jun. '19 and the best car ever), '03 SAP P71