If you own an older Cessna 172, similar to my 1981 model, you may not know that your primer O rings have dried out and are non-functioning when you prime your engine to start it. Figuring out which O rings are the right ones to replace them was a job that Aircraft Spruce did for me and saved me time and money. Mine were MS29513-012 Aviation Fuel Resistant O-Ring and .30 cents each.

Pacific L Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

*****

James M Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

AAA

Mark C Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

Outside oring on feul drain on wings

Dj S Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

They fit perfect for my original 68 Cardinal fuel caps

Travis S Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

Ditto.

Siskiyou A Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

Perfect fit!

Mario A Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

Replacement o ring to fix the gas drain valve.

Antonio G Verified Purchase

MS29513-012 AVIATION FUEL RESISTANT O-RING

good product

Worked great

Great service

As ordered, and fast delivery. Thank you for reasonable pricing of such small orders.

Did the trick!

Small but mighty! Good quality O rings!

These O rings fit and performed perfectly on the sump drain of my Kiowa helicopter.

These are o-rings. The -12 are the ones used on Scott fuel valves in some Senecas, Aztecs, and Seminoles. The maintenance manual says to lube them with stop lock grease, which is a made up term that no one is familiar with. The correct grease is DuPont Krytox 240AC, which is very expensive. Dont use anything else though, since the o-rings have to slide on every flight (if the checklist is followed), and failure of these o-rings could cause the fuel selector to get stuck on off, or crossfeed into the other tank. Kinda important. If the selector valve is hard to move, or you notice fuel cross feeding into opposite tank while parked, then these valves need overhaul. Takes forever to remove and reinstall.