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Old 01-01-2019, 11:39 PM   #1
SilveradoDude
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Question Smog pump removal

I have already poured through all of the existing threads and i couldn't find any answers to the following question pertaining to smog pump removal.

What size plugs are used in the manifolds after the injection pipe removals?

Last edited by SilveradoDude; 01-02-2019 at 12:11 PM.
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Old 01-02-2019, 05:41 PM   #2
andyh1956
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Re: Smog pump removal

If I remember right they are Inverted Flare Plugs but don't remember if they were 3/8" or 5/16" but I bet they were 3/8".
I've seen no end of folks crank 1/4" Pipe plugs down in there.
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Old 01-04-2019, 08:37 PM   #3
kwmech
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Re: Smog pump removal

5/16 flare plug. Do not use a 1/4 pipe plug, threads are different even though you can jam them in and possibly crack the manifold if too tight.


Since you are removing the pump, do you have a catalytic convertor?
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Old 01-04-2019, 09:45 PM   #4
SilveradoDude
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Question Re: Smog pump removal

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Originally Posted by kwmech View Post
5/16 flare plug. Do not use a 1/4 pipe plug, threads are different even though you can jam them in and possibly crack the manifold if too tight.

Since you are removing the pump, do you have a catalytic convertor?
Yes I still have the converter. What else needs to go? And can i get these plugs at Lowes or Home Depot? (Brass or Stainless??)
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Old 01-05-2019, 03:00 AM   #5
Gregski
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Re: Smog pump removal

Quote:
Originally Posted by SilveradoDude View Post
I have already poured through all of the existing threads and i couldn't find any answers to the following question pertaining to smog pump removal.

What size plugs are used in the manifolds after the injection pipe removals?
starts around thread #93

http://67-72chevytrucks.com/vboard/s...=645440&page=3

then it was off to Home Depot (well two of em since the first only had 5 of the fittings)

thanks to the good folks on this forum sharing their know how I was able to determine I needed the Brass Pipe LFA-737 plugs

can you see my plug in the red 1/4 inch (8mm) slot I screwed in to the store to show you guys what we need
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Old 01-05-2019, 03:24 AM   #6
kwmech
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Re: Smog pump removal

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Originally Posted by SilveradoDude View Post
Yes I still have the converter. What else needs to go? And can i get these plugs at Lowes or Home Depot? (Brass or Stainless??)
May as well ditch the convertor then, removing the air pump will make the convertor run colder negating what it is supposed to do.
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Old 01-05-2019, 10:50 AM   #7
SilveradoDude
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Question Re: Smog pump removal

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Originally Posted by kwmech View Post
May as well ditch the convertor then, removing the air pump will make the convertor run colder negating what it is supposed to do.
So Gregski is saying 1/4 and you are saying 5/16, which is i? I am pretty sure HD doesn't carry 5/16 plugs anyway.


I want to get rid of the EFE/TVS plugs on the intake manifold do you know what plug size will work for these?
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Old 01-05-2019, 06:14 PM   #8
SilveradoDude
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Question Re: Smog pump removal

So after spending an hour and a half searching I can tell you that neither Lowes nor HD carry the plugs for this which are 5/8 and FINE THREAD. I ended up just pinching the line the close them off.

I did encounter a problem with the truck cutting off when I put her in drive (but not reverse) am I missing something vacuum wise??
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