This from the 1995 Chevrolet Motor Home Chassis Service Guide. It was omitted by GM in the later 1997 version which is on the Barth CD.

Chevy P32 Vaporlock Issues - vapor_lock_App7-7.pdf

link to 1979-1986 Chev Chassis Service Guide, which covers at least all the Winnebagos of that time

Bouncing forward because it's hard to find

https://barthmobile.com/groupe...ide_PG_1979-1986.pdf