Hi fellows,

My 2004 UL with air suspension has leaking oil on the top of the strut as the photo shows.


I did some research online, the air strut used to fulfill with air and no hydraulic oil in it.
I will clean the oil to see if it will appear again.

Do you guys have any idea of this.
Should I need to replace the air strut in this situation?

Thanks,

 

The air-strut does have oil in it for the damping. It uses air for the spring and oil for the damping.
If the strut is suffering from poor damping then it will need to be replaced.
Otherwise it could be whoever fitted the strut oiled the top of it for some reason.

The little motor on top of the strut is controlled by the suspension computer and adjusts the amount of damping.

 

Thanks a lot, BigBoomer!
I will check them again carefully.

 

I had one leaking air strut in the front and one leaking in the rear, meaning I faced having to replace all 4. At the time, mail order was like $1.2k each, list around $2k each. I decided to replace the suspension with OEM coils/struts. PM me if you want the parts list. Cost me around $3.3k for parts including new lower control arm ball joints using a CL discount code, about 12 hrs for installation ($1.6k) back in 2018. So about $5k for a car that drove like new at 131k miles. Now have 195k miles, still drives great. Roads where I live now in No VA are well-maintained, and speeds are much slower (50-60mph vs 80-85 in NM), so much less wear & tear on the suspension.