Sticky or Best Thread for Air Supsension Diagnostics?
#1
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Thanks for the great posts. Having air suspension issues myself for the first time - has someone written a step-by-step, how to diagnose issues? I don't have a good indie in my town, dealer is horrible, and I'm just starting to get the 'too low' and "air suspension fault" indicators. I suspect the control system, but don't know how to go about checking it out, piece by piece. Thanks - 2004 XJ8
#3
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As far as I can recall, there have been no documented cases of Air Suspension Control Module (ASM) failure. By far the most common issues are air leaks and a worn piston ring seal in the air compressor.
What are the circumstances when you get the Vehicle Too Low and Air Suspension Fault warnings? Is it shortly after starting the car and commencing to drive, or is it after you've been driving awhile?
Don
#4
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HI. I spent the day on it, and while it does seem to periodically vent all air, I have developed a large leak, up front, which is now my focus. Once I get it pressurized, it cycles between running the compressor for 10 seconds, then lasting 25 seconds, then running the pump for 10 again, and so on. Pretty large leak that lets out enough air in 25 secs. Have sprayed soapy water over fittings, but no leak there. I can't figure out how to access front struts to see if they are the source of the leak. I asked on another thread how to get to them (short of simply removing them)?
Thanks.
Thanks.
#5
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HI. I spent the day on it, and while it does seem to periodically vent all air, I have developed a large leak, up front, which is now my focus. Once I get it pressurized, it cycles between running the compressor for 10 seconds, then lasting 25 seconds, then running the pump for 10 again, and so on. Pretty large leak that lets out enough air in 25 secs. Have sprayed soapy water over fittings, but no leak there. I can't figure out how to access front struts to see if they are the source of the leak. I asked on another thread how to get to them (short of simply removing them)?
Thanks.
Thanks.
I have moved your posts to your own thread.
The most common leak points in the air spring/shock absorber units are at the top seal or the air bladder itself. The edge of the top seal can be seen around the perimeter of the circular recess in the top of the unit around the electrical connector for the ECATS solenoid valve. You can spritz soapy water around that edge to check for leaks, just take care not to wet the electrical connector.
The air bladders are hidden by a cylindrical cover, so you can't visually confirm a leak, but you may be able to hear the leak in the wheel well when the system is charged or charging.
Thus far, there is no DIY solution for a leaking top seal or bladder, so the only permanent solution is to replace the air spring/shock absorber, and unless you can find a good used or rebuilt OE Bilstein unit, you will probably need to replace both front units so their performance will match.
OE Bilstein units are available from Jaguar dealers and other sources, and at least one or two companies offer aftermarket units, including Arnott Industries. Arnott used to also rebuild OE units, but no longer do. However, I have heard reports of another company that is now rebuilding Bilstein units. Search the forum for other options.
Cheers,
Don
Last edited by Don B; 05-21-2017 at 04:19 PM.
#6
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Thanks for taking the time. I was hoping to avoid having to remove both front struts to figure out which is leaking, but guess I have no choice.
I remember someone talking about a new remanufacturer of struts - RMI or RMP or something like that. I"ll see if I can find that name.
Thanks again.
I remember someone talking about a new remanufacturer of struts - RMI or RMP or something like that. I"ll see if I can find that name.
Thanks again.
#7
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RMT, haven't used them just keeping them book marketed as a possible source when the day comes.
Jaguar XJ-Series 2004-2010 Air Suspension Parts & Conversion Kits
Jaguar XJ-Series 2004-2010 Air Suspension Parts & Conversion Kits
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#8
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RMT, haven't used them just keeping them book marketed as a possible source when the day comes.
Jaguar XJ-Series 2004-2010 Air Suspension Parts & Conversion Kits
Jaguar XJ-Series 2004-2010 Air Suspension Parts & Conversion Kits
#10
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Don B (05-21-2017)
#11
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Thanks for all the info.
Actually, my front leak is so bad the front drops noticeably within 30 seconds. No need for a fancy gauge over time for detecting a slow leak.
I just need to figure a way to plug up the airhose on one side, and then the other. If I have a blow shock (fronts only have 30,000 miles on them) then I should be able to tell pretty quickly if can plug one side then the other. Maybe I can find a brass fitting that I can screw onto the brass nipple at the end of the air tube. I'll experiment and let you know.
Thanks for the support. Still going to build a gauge, as I want to keep the air suspension and figure I'll have issues again.
Dave
Actually, my front leak is so bad the front drops noticeably within 30 seconds. No need for a fancy gauge over time for detecting a slow leak.
I just need to figure a way to plug up the airhose on one side, and then the other. If I have a blow shock (fronts only have 30,000 miles on them) then I should be able to tell pretty quickly if can plug one side then the other. Maybe I can find a brass fitting that I can screw onto the brass nipple at the end of the air tube. I'll experiment and let you know.
Thanks for the support. Still going to build a gauge, as I want to keep the air suspension and figure I'll have issues again.
Dave
#12
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Cheers,
Don
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#14
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Thanks for the help. My leak was so bad that I only had to isolate which side it was on, and if for sure it was the strut. So, I went to Ace Hardware, and for $3.50 they had a brass 'cap' - a 1/8" plumbing line cap. I disconnected the air hose at the top of the strut, screwed on the cap tightly, which made for an air-tight seal. I then started the car, pressurized the system, and it didn't leak, so I know I need a new right side strut.
Former owner replaced the strut 4 years and 28,000 miles ago. Not too impressed with Jaguar struts. They are only warrantied for 12 months!
Former owner replaced the strut 4 years and 28,000 miles ago. Not too impressed with Jaguar struts. They are only warrantied for 12 months!
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#15
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Well done on your diagnostics and great tip on the 1/8 in. pipe fitting brass caps!
Cheers,
Don
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