Vince
The R59681 Hygroscopic vent cap should thread on to the air vent until it stops. If the cap continues to spin there may be a problem with the threads on the air vent or inside the cap. The caps are supposed to come with the Hygroscopic discs in them (8 brown, 1 red) If these are missing from the cap when you get them please let us know. We can be reached at (414) 238-2360 ( Monday through Friday) or we can be reached via email at www.techsupport.us@caleffi.com
Vince
The R59681 Hygroscopic vent cap should thread on to the air vent until it stops. If the cap continues to spin there may be a problem with the threads on the air vent or inside the cap. The caps are supposed to come with the Hygroscopic discs in them (8 brown, 1 red) If these are missing from the cap when you get them please let us know. We can be reached at (414) 238-2360 ( Monday through Friday) or we can be reached via email at www.techsupport.us@caleffi.com