Town Car air suspension problems? Read this thread!

[sturgigk]

You have a slow leak in the suspension system.
97% chance it is the rubber air bags starting to leak at the fold.
2% chance there is a leak at rubber O rings.
1% chance it is something else.

If the system is pumping up during driving, what can be said is ....
The compressor is working because it is what is pumping air into the system
The module is working because it is getting signals that the body dropped
The height sensor is working because it gives the signal to the module
The actuator is working because it lets in air from the compressor.

Which only leaves the bags, lines and connectors.
Rare is a line or connector failure.

Which leaves the bag.

Also know that the actuator, the module, the compressor, lines and connectors are all independant. If an actuator fails, it can be replaced without removing the bag. Same with everything else. You can over repair if you want. However there isn't much to be gained other than your bank account showing a lower balance.

And I agree with you. Metal springs suck. Did I say that out loud?

Action

Action,
You were a great help on suggesting to replace the air bags. I had that done back in April along with the O rings. My problem has partially returned now with the rear dropping overnight although it usually pumps back up after letting the car engine run a few minutes. However on Thursday it raised on the right side but continued low on the left side and would not raise even after driving it awhile. Should my next step be replacing the actuator (is the the same part as the air suspension solenoid/valve? Are there 2 solenoid in the rear, one for each side or only one for the whole system? Anything else I should consider replacing? Thanks again for your advice!

 

[Action]

Unless you have a lot of cash you like to blow, diagnose first.

If it were me, I would raise the vehicle so I could get under it.
Remove, inspect and clean as needed electrical connectors
The start engine and operate the system until the pump is done. Shut off engine.
Spray soapy water on lines, the air springs and anything that handles air.

You are looking for a leak. (O ring or ???)
If no leak, then it is an electrical control issue. (actuator or height control if independent rear axle)

Action

 

[sturgigk]

Thanks so much! The O rings were replaced along with the air bags in April but I’ll ask the shop where I had it done to check for leaks. I unfortunately don’t have the tools and skill set to attempt this myself. For some reason though they let me buy parts usually at much less costs (esp. on Rock Auto) and install them for me. Maybe some of their work in April hasn’t held up. I won’t be going to traditional springs for sure!

 

[Dunkelbierkoenig]

Hi, I hope I'm adding to the correct thread: My Town Car (2005 Signature Limited) recently out of the blue developed a problem with the air suspension: The back is all the way to the ground, and even though the compressor is running (several times upon start up, until it turns on the "air suspension" light and throws code C1726, pneumatic failure which doesn't really help much) the rear doesn't lift a bit. Yesterday I did a quick inspection and couldn't find any obvious issues (airbags are 2-3 years old and look fine), all lines/cables are connected and don't seem to be broken. And given that the compressor dutifully starts up and tries to lift the car I'm thinking that sensor and RASM are working fine.
I'm a bit at a loss here and appreciate any input: If there was a leak it would normally show up slowly over time, right? And even then, wouldn't it only "lean" to one side as the sides are individually controlled by the solenoids?
So the only thing I can come up with (please add if I'm missing something):

- Vent solenoid stuck open (would this show up in the module self test?)
- unidentified leak in the line affecting both airbags
- Dryer suddenly completely clogged
- compressor failed even though it's still running (Can I just pull the airline and test if air is coming out, i.e., hold my thumb over it?)

I'm hoping to fix this soon as aim planning a longer trip at the end of September and I really don't won't to throw the coil spring kit in, so any help is much appreciated!! Thanks!

Edit: I should add that a week before it was working absolutely fine as I loaded a bunch of tiles and thinset and, to the amusement of the bystanders, enjoyed watching the car rise back to level in the home depot parking lot). Could this have somehow "broken" something?

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[Action]

Hi, I hope I'm adding to the correct thread: My Town Car (2005 Signature Limited) recently out of the blue developed a problem with the air suspension:

This is a thread with 300+ posts. What is a few more?

The back is all the way to the ground, and even though the compressor is running (several times upon start up, until it turns on the "air suspension" light and throws code C1726, pneumatic failure which doesn't really help much) the rear doesn't lift a bit.

Kudos for pulling and posting the code. Not really a shocker in what the code means. There is no air in the system for the rear if the vehicle if the rear is all the way down and does not come up. I would suggest turning off the system with the switch. (unless testing) Continued operation of the compressor will damage the compressor. The compressor is not designed for continous running. Only for topping off the system after a height adjustment.

Yesterday I did a quick inspection and couldn't find any obvious issues (airbags are 2-3 years old and look fine), all lines/cables are connected and don't seem to be broken. And given that the compressor dutifully starts up and tries to lift the car I'm thinking that sensor and RASM are working fine.
I'm a bit at a loss here and appreciate any input: If there was a leak it would normally show up slowly over time, right? And even then, wouldn't it only "lean" to one side as the sides are individually controlled by the solenoids?
So the only thing I can come up with (please add if I'm missing something):

- Vent solenoid stuck open (would this show up in the module self test?)
- unidentified leak in the line affecting both airbags
- Dryer suddenly completely clogged
- compressor failed even though it's still running (Can I just pull the airline and test if air is coming out, i.e., hold my thumb over it?)

Edit: I should add that a week before it was working absolutely fine as I loaded a bunch of tiles and thinset and, to the amusement of the bystanders, enjoyed watching the car rise back to level in the home depot parking lot). Could this have somehow "broken" something?

If the dryer was completely clogged, it would not allow the compressor to add air in the system. However it would also NOT allow air out. I do not think the dryer is the issue. However if it is original I might be inclined to replace as a maintenance thing if the opportunity is there.

The other 3 items you came up with are possibilities in my opinion. However the one that is the most common issue is the system has an air leak.
Yes a solenoid not functioning correctly (stuck in one position) would generate a code. That didn't happen.
Yes you can pull the line out of the end of the compressor and see if there is air pressure coming out. I would do this.

And the most common issue is an air leak.
One other item would be a leaking O ring(s). Which would generate an air leak. There are many. Even at the compressor/dryer
If you have a helper and compressed air, after I removed the air line from the compressor end to see if the compressor is pumping. I would blow some shop air into the line disconnected from the compressor. It won't be pretty and should work. Then spritz soapy water along all of the system with a focus on the two rear air spring assemblies.

Because the most common issue of the system is an air leak.

Action

 

[Dunkelbierkoenig]

Thanks for your reply! Yes, I wasn't really sure how to test for leaks if there's no air going to the rear. When I jacked it up yesterday and tried to see if anything was out of the ordinary, the airbags looked fine (I replaced them 2-3 years ago when I bought the car) and both felt equally "solid", like they didn't feel soft when I tried to push them in on the side with my thumb, as if there was still a bit of residual air in the system. I'll go and try disconnecting the line on the compressor to see if I can feel air coming out.
And yes, currently I turned the system off to prevent the compressor from overheating.
And I'll also try to pump it up using my shop air, but I guess I'd need to turn the system on and try to pump it up while the compressor is running to activate the solenoids on top of the bags?

In parallel I might stop by at the local junkyard, they have a 2006 in stock and see if i can pull the compressor, module, and sensor as it seems those would be the most expensive items... I'll report back!

 

[Action]

Testing.
To do that and not have the compressor run. Disconnect the wire harness to the compressor.
Then turn on the system switch.
Then at least move the ignition key to the on position.
That will activate the system and not fire up tghe compressor.

Action

 

[oktowncar]

Jack up the rear, Grab a bottle with soapy water and liberally soak down the bags top to bottom. Look for bubbles.

The bags usually develop leaks at the very bottom of the bags.

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[Dunkelbierkoenig]

Thank you Action! I did not know that I could test the system like that. I was able to remove the air line from the compressor and when I turned on the system I felt the remaining air from the bags coming out of the line while the suspension completely bottomed out and even though the compressor rumbled on in his broken rubber mounts I couldn't feel any air coming out. Turns out even though Ontario is absolutely beautiful, especially this time of the year, the salt on the streets in the winter slowly kills everything. The pump body was completely corroded, cracked and even burst open. Guess I'm in for a new pump.

Side note: While the pump was running I was able to use shop air and a blow out gun to raise the rear (has some 70s street machine vibe now lol) and turn off the system, so now I can at least drive while waiting for the new pump.

Summary: Even when the pump is seemingly running it might not be able to do it's job so it's worth checking!

 

[Action]

Glad to see you got to the cause.

Not exactly what I would have expected and that is what diagnosis is all about.
Inspect and find the cause then order parts.

As to the environment, if it were me, I would wax the metal areas and treat the rubber/plastic areas of the new part.
Will make it easier to do a future repair and the new parts may have a longer chance of survival.

Action

 

[Dunkelbierkoenig]

Yes, I wasn't expecting this either, but I guess it'll be an easy fix. And yes, I get my Town Car sprayed with "Crown" every year, some rust prevention stuff to extend it's life a little longer. I'll apply a thick layer to the new pump before it goes in!

 

[bubbbbbbbbbas]

Rear bags are constantly flat but i have zero check suspension light. What could cause this, two popped bags?

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[Action]

Rear bags are constantly flat but i have zero check suspension light. What could cause this, two popped bags?

Bags do not pop. They just leak.

Typically a leak is the issue.
Usually an air bag leaking at the fold.

There are other possibilities and the above is typical.
Someone has t get under the vehicle and inspect to confirm that issue or confirm something else.

Action

 

[bbf2530]

Bags do not pop. They just leak.

Typically a leak is the issue.
Usually an air bag leaking at the fold.

There are other possibilities and the above is typical.
Someone has t get under the vehicle and inspect to confirm that issue or confirm something else.

Action

Hi Action. While it’s not the situation in this case, I can speak from experience that the airbags can pop (and worse).
Had one explode in my 1990 Town Car. Sounded like a shotgun blast and the rear end immediately dropped onto the bump stops.

Again, it’s not the situation in the case we are discussing, but it can happen.

Good luck.

 

[Action]

Hi Action. While it’s not the situation in this case, I can speak from experience that the airbags can pop (and worse).
Had one explode in my 1990 Town Car. Sounded like a shotgun blast and the rear end immediately dropped onto the bump stops.

Again, it’s not the situation in the case we are discussing, but it can happen.

Good luck.

I have never heard of a Ford air spring bag exploding. Never seen it reported in any thread or by any techs.
You are the only one that I have ever heard of that reported that.

Action

 

[oktowncar]

Absence of a dash light means that
A- the system is working as it should
B- there is a fault in the height sensor
C- Dash light bulb is burned out

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[bbf2530]

I have never heard of a Ford air spring bag exploding. Never seen it reported in any thread or by any techs.
You are the only one that I have ever heard of that reported that.

Action

Hi Action. Then aren’t I the lucky one that it happened to me.
And now you have heard it. Not as loud as I and the people in the car at the time heard it though.

Good luck.

 

[Dunkelbierkoenig]

Rear bags are constantly flat but i have zero check suspension light. What could cause this, two popped bags?

Just had the exact same, car randomly dropped to the ground after driving over a speed bump. Turned out that the link between axle and ride height sensor got disconnected and was dangling freely, thus allowing the sensor to register the suspension being all the way up, which in turn caused the it to completely deflate and NOT turn on the air suspension light as the system thought that everything was fine. Jacked it up, reconnected the link and all is fixed.

 

[bubbbbbbbbbas]

Absence of a dash light means that
A- the system is working as it should
B- there is a fault in the height sensor
C- Dash light bulb is burned out

So it appears a height sensor is off of the post but i cant find the proper spot for it to latch on. I have a severed hose right next to the drivers side bag.

 

[bubbbbbbbbbas]

Is this going to be a air supply hose? If so i think i will call it quits with the air suspension and put in springs.