Air Suspension & ECATS System Summary: Components & Operation
#21
05-08-2018, 04:11 AM
Hi JHB,
So far, the consensus is that the cold air leak occurs at the top seal of one or more air springs, typically one or both of the fronts. The top seal is a large rubber molding that is permanently compressed between inner and outer components in the air spring/shock absorber and is not replaceable. You can see part of the seal as a rubber ring around the circumference of the recess of your air springs, in the center of which is the ECATS solenoid electrical connector.
You can check for leaks at the top seal on a cold day by running the engine to charge the air suspension, then spritz some soapy water around the recess in the air spring, taking care not to wet the ECATS connector. Bubbles indicate a leak.
A few owners have attempted repairs by packing this recess with epoxy resin to seal the area where the seal is visible. Only time will tell if these repairs will last. I have considered attempting to apply a high-pressure sealant to that area while pulling a slight vacuum on the air spring to help draw the sealant into the leak(s), but the only suitable high-pressure sealant I've found is expensive, so I keep putting off the attempt.
The most expedient solution is to replace one or both air springs/shock absorbers.
Cheers,
Don
So far, the consensus is that the cold air leak occurs at the top seal of one or more air springs, typically one or both of the fronts. The top seal is a large rubber molding that is permanently compressed between inner and outer components in the air spring/shock absorber and is not replaceable. You can see part of the seal as a rubber ring around the circumference of the recess of your air springs, in the center of which is the ECATS solenoid electrical connector.
You can check for leaks at the top seal on a cold day by running the engine to charge the air suspension, then spritz some soapy water around the recess in the air spring, taking care not to wet the ECATS connector. Bubbles indicate a leak.
A few owners have attempted repairs by packing this recess with epoxy resin to seal the area where the seal is visible. Only time will tell if these repairs will last. I have considered attempting to apply a high-pressure sealant to that area while pulling a slight vacuum on the air spring to help draw the sealant into the leak(s), but the only suitable high-pressure sealant I've found is expensive, so I keep putting off the attempt.
The most expedient solution is to replace one or both air springs/shock absorbers.
Cheers,
Don
#22
05-08-2018, 08:49 AM
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A quick search of Sikaflex 260N seems to indicate that it is primarily used for bonding glass. I didn't see a pressure rating.... Do you know if it can withstand the 20 bar / 290 psi maximum bump pressure the air springs bladders can experience?
Cheers,
Don
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#23
05-08-2018, 03:33 PM
Hi Don, you are right, I think it was Sikaflex 11 FC or similar and not 260N.
I have used it to seal my gasoline inlet in my Volvo and also to seal for bit tanks. Of couse I don't know, if it could also seal up to 20 bar, but take a look on the datasheet, 1,5 N/mm² is the pulling force.
This should be equal to 15 bars.
I would give it a try, because the leak is very tiny and it can even better seal it. And it's quite cheap with 10 €.
I have used it to seal my gasoline inlet in my Volvo and also to seal for bit tanks. Of couse I don't know, if it could also seal up to 20 bar, but take a look on the datasheet, 1,5 N/mm² is the pulling force.
This should be equal to 15 bars.
I would give it a try, because the leak is very tiny and it can even better seal it. And it's quite cheap with 10 €.
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Don B (05-08-2018)
#24
09-15-2019, 07:20 AM
Member
Thanks so much for posting this, I've been trying to get an understanding for a while now about how the damping works. Everybody on the Facebook X350 page talks about the springs but not the damping. My car seems to have functional springs in so far as the ride height is correct but the car just rides badly in much the same way as a conventionaly sprung car would if the shock absorbers ( but not the springs ) were knackered.
Now , thanks to you I've established that there is indeed a 'conventional' hydraulic damping system inside the strut it seems not unreasonable to assume that damping can fail whilst the 'springs' are still OK.
Interestingly however, now I understand there's vertical accelerometers in the equation, then it seems possible that false information from them would case a similar symptom ( ie; the car is bouncy and feels underdamped ) is that likely?
I'm tempted to go down the conventional suspension conversion but can't find a supplier in the UK that actually answers the phone.
Now , thanks to you I've established that there is indeed a 'conventional' hydraulic damping system inside the strut it seems not unreasonable to assume that damping can fail whilst the 'springs' are still OK.
Interestingly however, now I understand there's vertical accelerometers in the equation, then it seems possible that false information from them would case a similar symptom ( ie; the car is bouncy and feels underdamped ) is that likely?
I'm tempted to go down the conventional suspension conversion but can't find a supplier in the UK that actually answers the phone.
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Don B (09-15-2019)
#25
10-21-2019, 04:35 PM
Thank you very much! I just bought a beautiful 2005 XJR with about 112,000 miles the front shocks did to absorb impact and the seller told me the Jag Shop said it needed new front air shocks. The ride height seemed to be good about 14 1/2” center to lip. I just installed new Bilstein front shocks and followed the Bilstein factory instructions to install them. Now i still have my car on my lift but the shocks are not raising the car or reacting in any way. Do you have any ideas what to do next? Thanks ,Mark
#26
10-21-2019, 05:48 PM
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#27
10-21-2019, 09:00 PM
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Thank you very much! I just bought a beautiful 2005 XJR with about 112,000 miles the front shocks did to absorb impact and the seller told me the Jag Shop said it needed new front air shocks. The ride height seemed to be good about 14 1/2” center to lip. I just installed new Bilstein front shocks and followed the Bilstein factory instructions to install them. Now i still have my car on my lift but the shocks are not raising the car or reacting in any way. Do you have any ideas what to do next? Thanks ,Mark
Your suspension is probably just in Jacking Mode, and as trampintransit mentioned, you may just need to drive the car to exceed 2 mph so it will exit Jacking Mode and resume proper operation.
Cheers,
Donh
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#28
10-21-2019, 10:11 PM
#30
08-24-2020, 04:05 PM
Junior Member
Front suspension drops when the temperature drops.
Hi There, I'm the proud Jaguar owner of a 2006 XJ8, and enjoy reading the articles that have ben posted regarding the air suspension problems. This is without a doubt the most comfortable ride I have experienced, and cannot understand why anybody would want to change it. Having said that, the question about it dropping in cold weather, is this normal or could the seal show that a greater problem is looming on the horizon?
As a young lad I left school and worked for the local bus/coach company and these vehicles like a lot of HGV use air bags and they go down due to small leaks around the mountings/pipes/connections, this would be normal as the compressor would always supply air to replenish the reservoir tanks.
The vehicle has mechanical warranty and I wonder if I should be asking for the offending strut/struts to be replaced. Any thoughts would be much appreciated.
As a young lad I left school and worked for the local bus/coach company and these vehicles like a lot of HGV use air bags and they go down due to small leaks around the mountings/pipes/connections, this would be normal as the compressor would always supply air to replenish the reservoir tanks.
The vehicle has mechanical warranty and I wonder if I should be asking for the offending strut/struts to be replaced. Any thoughts would be much appreciated.
#31
08-24-2020, 07:13 PM
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Welcome to the Jaguar Forums! It's great to have you with us.
The most common cause of the vehicle dropping in cold weather is a leak in the top seal of one or both front air springs. The top seals wrap around the aluminum top plate to seal the top end of the air spring bladder. My theory is that as the seal rubber hardens with age, when the aluminum top plate contracts in cold weather, the seal loses contact with the aluminum, allowing air to escape. You can test for this in cold weather by starting the engine and allowing the air compressor to run until it shuts off (typically 2 minutes), then spritz soapy water around the perimeter of the recess in the top of the air spring. Avoid getting water on the electrical connector for the CATS solenoid. Watch for bubbles in the soapy water - if you see them, you've found your leak.
The top seals are not replaceable, so new air spring/damper units are the typical solution, and for safety they really should be replaced in pairs, since having front dampers that behave differently can lead to vehicle instability on rough surfaces and while cornering.
Cheers,
Don
Jaguar suspension issues
#33
01-17-2021, 07:46 AM
Senior Member
Fantastic Don
Wow Don thank you for such a complete summary of info .
Believe it is rather good to get to know the air suspension before getting in trouble with it. .
Just got new tyres on my 2003 xj8 .After i paid the bill ,both lights orange and red lit up , I waited a minute in P mode then drove carefully around the bloc , still . Chut of the engine ,started again and the red one was gone.
next morning the orange light was gone as well.
Believe it is rather good to get to know the air suspension before getting in trouble with it. .
Just got new tyres on my 2003 xj8 .After i paid the bill ,both lights orange and red lit up , I waited a minute in P mode then drove carefully around the bloc , still . Chut of the engine ,started again and the red one was gone.
next morning the orange light was gone as well.
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Don B (01-17-2021)
#34
02-24-2021, 02:13 PM
Junior Member
Hi Don, not sure if I replied to your answer, but thanks for the reply. It's been nearly 7 months since the puchase of the XJ8 and things have been going well, the weather is warm and the suspension is fine, there did seem to be a slight drop in ride height but not an issue, will have to wait for the cold weather to return see if it gets worse.
Thanks again.
Thanks again.
Last edited by BRITABROAD; 02-24-2021 at 02:14 PM. Reason: spelling mistake
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Don B (02-25-2021)
#35
07-23-2021, 06:55 PM
#36
07-23-2021, 10:08 PM
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Welcome to the Jaguar Forums! It's great to have you with us.
Yes, it would be possible to splice an inline fitting between the valve block and reservoir, but any loss of pressure caused by using the reservoir as an auxiliary air supply for other purposes would probably prompt the ASM to trigger leak-related diagnostic trouble codes, which would potentially disable the compressor, undermining your purpose. An inexpensive battery-operated air compressor would be a better option.
Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.
Cheers,
Don
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#37
02-23-2022, 05:00 PM
I would like to view the compressor brochure, but when I click the “WABCO Air Compressors Brochure” link it gives me an error message about the site not being available, or being moved, or some such thing. Maybe I have not been granted access to links yet? I am a relatively new member to the forum, so maybe that is the case? If so, could I get privilege to see the links?
here is the exact error message I get when I click the link:
here is the exact error message I get when I click the link:
404 - File or directory not found.
The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.
Last edited by MnLMcC; 02-23-2022 at 05:04 PM.
#38
02-23-2022, 07:05 PM
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I would like to view the compressor brochure, but when I click the “WABCO Air Compressors Brochure” link it gives me an error message about the site not being available, or being moved, or some such thing.
As so often happens, that link to a document on the WABCO website has gone dead.
I am attaching the WABCO ECAS Passenger Car system Brochure and will ask Graham to upload it to the forum's file storage so I can update the link in my original post.
Cheers,
Don
Last edited by Don B; 02-23-2022 at 07:09 PM.
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EssOess (04-17-2022)
#40
02-24-2022, 09:34 PM
Don,
Link for “WABCO Air Compressor Brochure” appears to be broken. (I don’t mean “WABCO ECAS Brochure”) I get this message when I try to open it:
Link for “WABCO Air Compressor Brochure” appears to be broken. (I don’t mean “WABCO ECAS Brochure”) I get this message when I try to open it:
404 - File or directory not found.
The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.
Last edited by MnLMcC; 02-24-2022 at 09:42 PM.