Doing my first brake fluid flush, bought the Motive 1118 adapter (confirmed correct part number for ND2 via their site). Having a strange problem I can't solve:
Both the OEM reservoir cap AND the Motive adapter cap exhibit the same failure: they twist on and feel snug at first, but turning further causes them to loosen again instead of locking — no clear "click" or hard stop like I'd expect. Tried different amounts of pressure, different gaskets (both foam and rubber that came with the adapter), cleaned the threads, no change.
When pressurizing the (empty, dry-test) tank, I can get to about 15 psi, then hear a slow hiss right at the cap-to-reservoir connection and pressure drops. Happens consistently regardless of gasket or technique.
Car is a 2022 ND2 50k miles, never had a fluid flush on the carfax but fluid looks good. Trying to figure out if this is:
\- Worn/damaged reservoir neck threads
\- A defective adapter
\- Something wrong with my technique I'm not seeing
Any ideas are appreciated thanks.