Hey guys and gals,
My smog pump had its pulley removed, and the fresh air injection hard lines that come off of the exhaust manifold joined into one rubber hose, and the metal piping was split in half.


The previous owner put some sort of exhaust tape around it, but it still lets a lot of exhaust into the cabin.


I initially wanted to replace this system, but the air injection piping doesn't seem to be available new. I was searching for 'emissions' components, and 'air injection' to no avail. I'll wait until I have more time and money to restore this system, as I do appreciate clean exhaust. Not only for the environment, but for the sake of idling at the stop light :P It would be possible to buy hard lines and make my own flanges, and recreate the tubing, but I'm not at that point yet.

I'm trying to plug the air line threads in the exhaust manifolds. I visited a few auto parts stores, and ACE Hardware... I can't find a correctly sized bolt. Their generic bolt sizing grids didn't help, and they had threads to test, yet they didn't have this size. They didn't even have big enough nuts for me to thread onto this guy. Almost looks like a 9/16" tranny line flange.






The entire bolt measures at 1/2" - outer diameter of the threads.


Am I measuring this correctly? Thread pitch looks to be 20 threads per inch [I only measured a quarter inch and multiplied by four]. Would that call for a 1/2 x 20 bolt? Of which case would be... 1/2 x 20 Grade 8 Bolt

I know this may be elementary, but please let me know if this is correct Also, if anyone cares to correct the typo in the title, that would be good.

Thank you all,
-TunaTrky

 

try 1/4 inch NPT brass pipe plugs

They'll screw in, then after a few turns begin to get into the taper and seal.

 

I'll have to look into that, that's good to know. Unsure of using Grade 8 bolts will hold up, but we'll see. Air injection plug size: 1/2" x 20 threads per inch - in case anybody finds this. I found some 1/2" long grade 8 bolts at ace hardware. Manifolds are plugged and exhaust leak has been repaired.

 

Pretty sure what you have done is just begun to cross thread the bolts...but it it doesn't leak, what the heck!

 

You're right, as long as it doesn't leak!

 

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