I have an intermittent problem with my air suspension as follows: Most of the time i can leave the car parked up for a week, and it will sit quite happily at proper ride height. Occasionally though, the front drivers corner will drop in a couple of days or so, but then it will be ok again. Any suggestions anyone?
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Intermittent air suspension leak
- Thread starter jimbob
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Strutmasters
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From what you described in your post, it sounds to me like the classic example of a leaking air bag. The leak is probably around the "fold" of the rubber at the bottom. Next time the car is up at proper ride height, turn the air ride switch in the trunk off. If the same results occurr then there is NO other option but an air bag leak. If you have any other questions, please let me know and I will be glad to help.
Thanks,
Strutmasters Team
Thanks,
Strutmasters Team
i'm just curious.. couldn't it be a leak at the F/Left air spring solenoid, in particular it's O-ring?
With the air-ride trunk switch off, all 4 air-spring solenoids should be 'closed'. But I'm thinking that if, aside from the O-ring, that the solenoid valve itself is leaking and in combination with another leak somewhere in the f/left air line, it would cause the front left (and only the front left) to drop.
So.. what am i missing?
With the air-ride trunk switch off, all 4 air-spring solenoids should be 'closed'. But I'm thinking that if, aside from the O-ring, that the solenoid valve itself is leaking and in combination with another leak somewhere in the f/left air line, it would cause the front left (and only the front left) to drop.
So.. what am i missing?
nevermind.. i think i got it.
If any of the 4 solenoids (or air lines) were leaking, all four springs will leak since they share a common manifold. Even with the air-switch ON and engine running, the pump would probably be running all the time and would eventually cut-out. And all 4 corners would drop.
If any of the 4 solenoids (or air lines) were leaking, all four springs will leak since they share a common manifold. Even with the air-switch ON and engine running, the pump would probably be running all the time and would eventually cut-out. And all 4 corners would drop.
Thanks guys,
I am just trying to understand if it could be the solenoid or not. Arent they mounted in the tops of each airbag? if so, i dont understand how, with the suspension turned off (and all solenoids closed), that if one of them is leaking all four corners would drop? surely the other 3 solenoids, being closed, would keep the other 3 bags inflated as being mounted in the tops of the airbags and closed, the air would not be able to get past them and out? Or am i not understanding exactly how the system works, im new to all this air suspension stuff!
One other thing that occured recently is that the 'check suspension' light would occasionally come on, but this has only happened within the last month (3 times in total) but this intermittent leak has been happening for 6 months (only occasionally too)? any thoughts?
I am just trying to understand if it could be the solenoid or not. Arent they mounted in the tops of each airbag? if so, i dont understand how, with the suspension turned off (and all solenoids closed), that if one of them is leaking all four corners would drop? surely the other 3 solenoids, being closed, would keep the other 3 bags inflated as being mounted in the tops of the airbags and closed, the air would not be able to get past them and out? Or am i not understanding exactly how the system works, im new to all this air suspension stuff!
One other thing that occured recently is that the 'check suspension' light would occasionally come on, but this has only happened within the last month (3 times in total) but this intermittent leak has been happening for 6 months (only occasionally too)? any thoughts?
Strutmasters
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If you have turned the switch off in the trunk, and the entire car drops, then you have bad news. In MOST cases that suggests that you have some type of leak in the air bags. You actually described it perfectly. With the switch in the trunk off, all of the solenoids are closed. All of the eloctronics are also off. As I said, in most cases, with the switch off if a bag drops you have a leak. The check air suspension light also suggests leaks. If you have any further questions, please let me know and I will be glad to help as much as possible.
Thanks,
Strutmasters Team
Thanks,
Strutmasters Team
jimbob.. check this out. I found it while messing with my air springs. It's a pretty good guide to the system. It differs slightly from the Service Manual and provided me with a little additional info. It has the diagnostic / troubleshooting procedure. It will familiarize you with the system components well enough to do some basic mechanical checks, and a lot more if you're so inclined..
http://www.lincolnvscadillac.com/tech/lincoln-mark-vii/AirSuspensionSystem/MarkVIISuspension.pdf
http://www.lincolnvscadillac.com/tech/lincoln-mark-vii/AirSuspensionSystem/MarkVIISuspension.pdf
Strutmasters
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Very, Very, nice link there joew!!!!!! Alot of good information in there.
Thanks again guys, that link looks excellent joew! ill be sure to read that through.
I have been doing the 'switch the suspension off and see if it drops' test. The same front corner has sunk, but it took a lot longer to drop than when the suspension was left switched on? does this indicate anything?
Strutmasters: Its looking like i may have to be ordering some parts for my car soonish, do you ship to the UK?
I have been doing the 'switch the suspension off and see if it drops' test. The same front corner has sunk, but it took a lot longer to drop than when the suspension was left switched on? does this indicate anything?
Strutmasters: Its looking like i may have to be ordering some parts for my car soonish, do you ship to the UK?
Strutmasters
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jimbob, yes we do! We ship world wide. Depending on the type of shipment there MAY be additional shipping charges, but I am sure we can work something out. IF you have any questions in the mean time, please feel free to ask. I will do my best to help in any way possible.
Thanks,
Strutmasters Team
Thanks,
Strutmasters Team
The solenoid might be just an additional leak avenue. If the solenoid is 'open', the bag leaks down faster than if a hole in the air-bag were the only way air could escape.. There could be more than one problem with the left side system.
But if activation or non-activation of the solenoid has a definate effect on it's own, it could be a clue.. perhaps the solenoid is defective in some way.
An fairly easy experiment would be to just switch the front left-right solenoids. If the right side bag inherits the enitre problem, you lucked out big time..
But if activation or non-activation of the solenoid has a definate effect on it's own, it could be a clue.. perhaps the solenoid is defective in some way.
An fairly easy experiment would be to just switch the front left-right solenoids. If the right side bag inherits the enitre problem, you lucked out big time..
Click
LVC Member
But if activation or non-activation of the solenoid has a definate effect on it's own, it could be a clue.. perhaps the solenoid is defective in some way.
An fairly easy experiment would be to just switch the front left-right solenoids. If the right side bag inherits the enitre problem, you lucked out big time..[/QUOTE]
Same problem here. In fact I don't see how it can be an air-bag leak when its so variable in timing.?
My rear-end goes down intermittently, sometimes while parked, sometimes on the road. By turning off, and on, the ignition it readjusts to the correct height for a while, then seems to loose its memory and sinks to the lowest level again. Other days it remains consistent with no problems at all. Therefore I believe its an electronic issue, possibly with some module that controls voltage for levelling.
Can anyone please shed more light on this part of system?
An fairly easy experiment would be to just switch the front left-right solenoids. If the right side bag inherits the enitre problem, you lucked out big time..[/QUOTE]
Same problem here. In fact I don't see how it can be an air-bag leak when its so variable in timing.?
My rear-end goes down intermittently, sometimes while parked, sometimes on the road. By turning off, and on, the ignition it readjusts to the correct height for a while, then seems to loose its memory and sinks to the lowest level again. Other days it remains consistent with no problems at all. Therefore I believe its an electronic issue, possibly with some module that controls voltage for levelling.
Can anyone please shed more light on this part of system?
There are little adjustable height controllers on each front wheels and one in the back in the center. Perhaps the one in back has a loose electrical connection or some other fault.
Grab that file
http://www.lincolnvscadillac.com/te...ISuspension.pdf
and go through the 10 (?) step testing proceedure... takes 10 minutes..
his is especially useful for diagnosing and pinpointing electrical-related faults. It's not so good at detecting leaks since the tests only feed back a PASS or FAIL on a particular component's operation.
Like if you can hear the front right solenoid clicking on and off, the test PASSes .. but the front right of the car can be on the ground due to a broken air line and it'll still pass that particular test.
Grab that file
http://www.lincolnvscadillac.com/te...ISuspension.pdf
and go through the 10 (?) step testing proceedure... takes 10 minutes..
his is especially useful for diagnosing and pinpointing electrical-related faults. It's not so good at detecting leaks since the tests only feed back a PASS or FAIL on a particular component's operation.
Like if you can hear the front right solenoid clicking on and off, the test PASSes .. but the front right of the car can be on the ground due to a broken air line and it'll still pass that particular test.
http://www.lincolnvscadillac.com/tech/lincoln-mark-vii/AirSuspensionSystem/MarkVIISuspension.pdf
link was broken.. this one works. So does the one in one of my previous messages.
This file comes from the "Announcement: Current Lincoln Mark VII Tech Articles " link on the main ...> Lincoln Mark VII forum page.
link was broken.. this one works. So does the one in one of my previous messages.
This file comes from the "Announcement: Current Lincoln Mark VII Tech Articles " link on the main ...> Lincoln Mark VII forum page.
I want to caution people about working under these cars.. If you accidentally cut or disconnect a air line or WHO KNOWS WHAT, the car might drop like a rock and trap bodies or body parts..
My front end is about one inch from the concrete when air fails and the car sinks. If you're under the oil pan when the air fails, you will be one inch thick.
Use support jacks and/or dont do stuff like stick your arm between a tire and the wheel well when dicking with the air springs.. BE freakin CAREFUL.. please..
My front end is about one inch from the concrete when air fails and the car sinks. If you're under the oil pan when the air fails, you will be one inch thick.
Use support jacks and/or dont do stuff like stick your arm between a tire and the wheel well when dicking with the air springs.. BE freakin CAREFUL.. please..
WALT
LVC Member
A few basic things that we must keep in mind is that the module will raise or lower the vehicle as it deems necessary from the height sensor inputs for ONE HOUR after the ignition is turned off and doors open / closed will affect what the module schedules. The logic for this is that as you remove load ( get out --remove stuff from trunk ) the system will trim ride height to compensate -- ever get some heavy stuff
out of the trunk then get " surprised " by the car moving ???? thats this key off adjustment taking place -- Turning the suspension switch off in the trunk cancels this 1 hr adjustment process but Many components still have HOT ALL TIMES power to them which can cause problems -- Leak check bags by pumping to ride height then disconnecting the battery to eliminate any possible shorted wiring / bad grounds
or corroded connections as the culprit ( Ford has extremely poor wiring harnesses especially on older vehicles-- insulation falls off / connectors not weather sealed ) -- let it sit overnight -- if you got a bad bag,
solenoid or solenoid seals -- they will show themselves --
Get a FACTORY manual ( Haynes / Chiltons just dont cut it for this kind of stuff )
Happy Hunting
out of the trunk then get " surprised " by the car moving ???? thats this key off adjustment taking place -- Turning the suspension switch off in the trunk cancels this 1 hr adjustment process but Many components still have HOT ALL TIMES power to them which can cause problems -- Leak check bags by pumping to ride height then disconnecting the battery to eliminate any possible shorted wiring / bad grounds
or corroded connections as the culprit ( Ford has extremely poor wiring harnesses especially on older vehicles-- insulation falls off / connectors not weather sealed ) -- let it sit overnight -- if you got a bad bag,
solenoid or solenoid seals -- they will show themselves --
Get a FACTORY manual ( Haynes / Chiltons just dont cut it for this kind of stuff )
Happy Hunting
American Air-1
Well-Known LVC Member
"IF" the solenoid has never been "disturbed", most likely its not going to be the leaking problem. If the leak is coming from the solenoid, it will be from the o-rings that seal the solenoid to the air spring.
Because the module goes to sleep after an hour, thus disabling the solenoids, you could actually disconnect the air lines from the solenoid altogether...and it wouldn't go down.
It is a really cheap fix if you want to try it first. You can match up the o-rings at any hardware store and give it a try. I don't really think its going to be your problem, but not knowing the cars history, who knows.
By all means, like any electronic device, turn the switch off before making any adjustments. With the switch off, the only way the vehicle will drop is if the solenoids are unlocked (twisted), thus letting all the air out.
Because the module goes to sleep after an hour, thus disabling the solenoids, you could actually disconnect the air lines from the solenoid altogether...and it wouldn't go down.
It is a really cheap fix if you want to try it first. You can match up the o-rings at any hardware store and give it a try. I don't really think its going to be your problem, but not knowing the cars history, who knows.
By all means, like any electronic device, turn the switch off before making any adjustments. With the switch off, the only way the vehicle will drop is if the solenoids are unlocked (twisted), thus letting all the air out.
I generally agree about the solenoid's o-ring being the only likely point for a leak, but the solenoid valve is just a valve.. and valves leak if some dirt or rust or something gets in there between the valve and it's seat. The combination of a leaking solenoid-valve and an air line or dryer-manifold leak can also do it.
As far as betting one's life on the trunk switch alone, i'd rather not.. I don't wanna admit being paranoid about it but after looking at the wiring diagrams ('88 Mk7), all it takes to open a solenoid is to accidentally ground it's ground wire while an air line is disconnected (or while the main exhaust solenoid in the pump is activated and venting).
What i see is that one of the solenoid's 2 wires goes directly to a fusible link near the starter relay and so would remain hot even with the trunk switch off. All that has to happen (if the battery is connected) is it's ground wire finds continuity with the frame someplace... and then the solenoid valve will pop open.
And, although i think this is unlikely, a little bit of stripped insulation on a solenoid's wire could actually be the source of a "leak", intermittantly grounding, bypassing the control system, opening a solenoid and dropping the car..
......
The Shop manual is riddled with cautions about working on the air spring system. Do they mention every possible way even a very careful person could avoid becoming a candidate for a Darwin Award? Probably not.
As far as betting one's life on the trunk switch alone, i'd rather not.. I don't wanna admit being paranoid about it but after looking at the wiring diagrams ('88 Mk7), all it takes to open a solenoid is to accidentally ground it's ground wire while an air line is disconnected (or while the main exhaust solenoid in the pump is activated and venting).
What i see is that one of the solenoid's 2 wires goes directly to a fusible link near the starter relay and so would remain hot even with the trunk switch off. All that has to happen (if the battery is connected) is it's ground wire finds continuity with the frame someplace... and then the solenoid valve will pop open.
And, although i think this is unlikely, a little bit of stripped insulation on a solenoid's wire could actually be the source of a "leak", intermittantly grounding, bypassing the control system, opening a solenoid and dropping the car..
......
The Shop manual is riddled with cautions about working on the air spring system. Do they mention every possible way even a very careful person could avoid becoming a candidate for a Darwin Award? Probably not.