You mean the deluxe, locking caps, right? Larry, I think your links are talking about the standard Van's fuel caps, which have some serviceability issues. I have the deluxe locking caps too Dave, and they seem to be very "loose" but held up well during pressure testing on my tanks, just the way they came out of the box. No adjustments and no soapy bubbles...
One place they can leak (blow bubbles during soap test) is around the shaft - you will find a small O ring that seal against the shaft - I have applied fuel lube on it - and on the large visible O ring .. then no issues ...
You mean the deluxe, locking caps, right? Larry, I think your links are talking about the standard Van's fuel caps, which have some serviceability issues. I have the deluxe locking caps too Dave, and they seem to be very "loose" but held up well during pressure testing on my tanks, just the way they came out of the box. No adjustments and no soapy bubbles...
Here's the Deluxe Locking Fuel Cap all in pieces. The pieces go together in the direction shown.
Tightening the nut only tightens the large o-ring against the filler neck riveted in the wing. There is no adjustment that lets you tighten the small o-ring that's around the stem. Lubricating it with Lubriplate doesn't stop air leakage past it.
There's another possible leak path around the lock's rotation cam but I haven't had the lock out so I have no information about that.
I drilled the black part to accept the lanyard. That's not stock.