Newton retrofit caps

[Taltruda]

Helping a buddy with those locking Newton retrofit caps that glue in with proseal.. we replaced both O-rings and they still leak.. visibly in flight. I don’t see a way to adjust them tighter.. any ideas with someone who’s been down this path?

 

[Flying EMT]

Tom, Check if its the proseal around the insert that is the leak. I had a regular cap that leaked. I finally fixed it (after changing o-rings and adjusting!) by cleaning under the ring the best i could and forcing proseal with a gloved hand up from the inside out. -Ben

 

[clam]

I installed these recently. First, I had minor leaks around the insert. This I fixed with additional proseal inserted with an animal syringe and needle from Tractor Supply. This allowed me to "poke" and "push" the proseal into voids. I thought I had a good bead originally, but I guess not. That sealed up well...

Now the caps leak slightly through the center of the cap when the tanks are full or near full with high ambient temperatures while inflight. I have not attempted to disassemble the caps, but that is next. I had hoped these would be an "upgrade", but the stock el cheapo kit caps look good in hindsight.

Tomorrow I'll take the caps apart, if that's possible, and look at the internals.
Not sure any of this helps you. Maybe others have solutions.