I would remove the solenoid and check the O-rings. Fluid would have to get past them in order to get into the solenoid itself.
I changed mine out with a kit from HWH, but you may be able to find a replacement from local hardware store.
Dan & Sharon (Zena-Our Yorkie Puppy)(Kasey-Our Yorkie Puppy RIP 9Jan05-26Jul17) On the Road (2012 Journey 36M, 2020 Chevy Equinox)
USN-Ret ('65-'93) Fulltimers, Class of 2012