Can't keep air in DNM USD-6 Fat fork on DIY build

[bombadero]

Hi, put an inverted fork on a DIY build I'm working on, a DNM USD-6 Fat fork. I cannot keep air in the fork, it will lose all air within about 24 hours. I have replaced the valve core and lightly greased the lowers, which did not work. I'm unsure what else to do as there is scant information in the fork manual or online regarding how to troubleshoot or take apart a USD fork. There are some diagrams that indicate they are built a bit differently; for instance, it seems like they would not be prone to oil leakage as the oil is contained in a cartridge. The seals seem fine, the fork is brand new with no obvious flaws, and it has zero mileage. I've contacted Kyle of Bolton E-bikes, since he owns a bike with the same fork, emailed DNM, and messaged the Amazon seller who sold it to me. Is there anything to be done besides trying to RMA the fork?

 

[fatty]

Not surprising, given their reputation.

You can try their US distributor -- very responsive:
CyclingDeal USA INC
sales@cyclingdealusa.com
PH: 909-397-4025

But you're probably best off returning it and getting a real shock, used on eBay or Pinkbike

 

[motomech]

Given that they are loosing that much air, pump them up and put them in a bathtub and see where they are leaking.
It's really has to be the fork seals and I'm not sure how one could determine they are fine by looking at them.They could not be leaking oil, but still leak air.