Anyone know who makes these valves with metal flaps inside, thanxs.

You could look at a NAPA CRB 229000. Not sure how they are made anymore. I do know they all break eventually and have to be replaced.

Anti-backfire valves used in vac-u-pan systems? Moroso still makes a kit and probably others may also. But it could be cheaper to cross-reference it to the emissions related OEM application, which, unfortunately, I don't recall. I use to use a bigger version. (Rock Auto?)

Summit vac-u-pan parts

I think that NAPA piece is correct. 3/4 nipple, 1/2"NPT. The Moroso valves are 20 couple dollars and I have no issue with anything they sell. Like I said, I consider those things to be consumables. Always had to replace a couple during the season.

STANDARD MOTOR PRODUCTS AV7T or AV7 about $9 @rockauto


Joe

Yep. Original application.....1983 Chrysler Fifth Avenue 318, (among many others).... A.I.R./smog pump check valve.

Breather caps-same, or pretty much any chrysler product down to 1970.

Some time ago I heard that the breathers can have different internal material. Avoid anything with foam because it clogs faster and those with metallic guts work best, which is like stainless, curly strands all bunched up inside.

Yea that's what I'm trying to find. Read somewhere that the furd check valves have a metal disc with stainless spring, but can't find anything.

NAPA website is good for looking stuff up by application and getting photos, specs, etc. I expect it will take a trip to the store to physically look at the thing to see how it's made. 3/4 nipple with 1/2NPT threads is the typical deal. Late 70s-80s GM used them on their AIR systems as well.

The breathers are not all the same. The breathers Moroso sells for the Vac-u-pan are different from the ones used strictly for a vent. Looser I believe to allow the system to be more efficient. At least that's how it used to be.