Annoying new suspension problem

stjohnsmythe · Nov 4, 2012

Ok, so had an advisory on the MOT that the rear bags were looking a bit worse for wear. So I purchased two new OEM Dunlop bags and had them fitted by a local indy last week.

Before I went to pick the car up Saturday morning, they called and told me that the rear passenger side overnight had dropped slightly. They've re-checked the whole system externally for leaks and can't find any. They mentioned that it might be a valve in the EAS valve block but that doesn't make any sense as the suspension was fine with the old bags?

Any ideas?

Datatek · Nov 4, 2012

Yep you have a leak, probably where the pipe goes into the airbag. As they are Dunlops it could be the bag not well seated on the end cap.

stjohnsmythe · Nov 4, 2012

Datatek said:
Yep you have a leak, probably where the pipe goes into the airbag. As they are Dunlops it could be the bag not well seated on the end cap.

Thanks for replying. I always thought that if there was a leak then the whole car would drop as the system tries to compensate/self level? Wouldn't dropping in just one corner point towards a height sensor or calibration problem?

Datatek · Nov 4, 2012

stjohnsmythe said:
Thanks for replying. I always thought that if there was a leak then the whole car would drop as the system tries to compensate/self level? Wouldn't dropping in just one corner point towards a height sensor or calibration problem?

If the leak is too great the EAS will not compensate. Dropping when parked suggests a leak, however if a height sensor has been over run when the bags were done it could be giving erratic readings, but that would also show when driving, you could only tell with diagnostics.

stjohnsmythe · Nov 4, 2012

Datatek said:
If the leak is too great the EAS will not compensate. Dropping when parked suggests a leak, however if a height sensor has been over run when the bags were done it could be giving erratic readings, but that would also show when driving, you could only tell with diagnostics.

Yea, it's fine when driving. Looks like I'll be taking back to them to find the leak.

TAKdriver · Nov 4, 2012

Datatek said:
Yep you have a leak, probably where the pipe goes into the airbag. As they are Dunlops it could be the bag not well seated on the end cap.

Is that a known prob with Dunlops ? That's what I've fitted : I have a minor leak which is simply an inconvenience but I can's find it.
I had to cut/drill out the old bags due to severe rusting of pins and may have caused a minor deformation of the seat.
Would you recommend that I take the bag back out and ensure seat is precise ?

dave4x4 · Nov 4, 2012

I've used a temporary isolating valve in the past to help pinpoint a problem. I used a cheap plastic 6mm valve from Ebay.
De pressurise, fit the valve in the airline to the suspect air bag, re-pressurise, level the car, take out the EAS relay, close the isolating valve to the air bag. If it goes down overnight it is definitely the air bag. If it stays up it is a valve box problem.

wammers · Nov 5, 2012

TAKdriver said:
Is that a known prob with Dunlops ? That's what I've fitted : I have a minor leak which is simply an inconvenience but I can's find it.
I had to cut/drill out the old bags due to severe rusting of pins and may have caused a minor deformation of the seat.
Would you recommend that I take the bag back out and ensure seat is precise ?

Think he means the seating of the actual bag. Not the seating of the unit in the car.

Annoying new suspension problem

stjohnsmythe

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Datatek

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stjohnsmythe

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Datatek

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stjohnsmythe

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TAKdriver

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dave4x4

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wammers

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