air pump removal

[guitarfreak235]

im trying to take off the air pump and related smog equipment in preparation for headers and exhaust, i know ive asked about this before. i think i remember somewhere someone said you could put a bolt in where the air tube goes in the manifold but i cant find it.... so does anyone know what im talkin about?? what bolt could i use?

 

[Jims86]

im trying to take off the air pump and related smog equipment in preparation for headers and exhaust, i know ive asked about this before. i think i remember somewhere someone said you could put a bolt in where the air tube goes in the manifold but i cant find it.... so does anyone know what im talkin about?? what bolt could i use?

when you get your air tube off of the manifold, take it to the hardware store and match up the threads and diameter with a cast iron or steel pipe plug.

 

[89Suburban]

when you get your air tube off of the manifold, take it to the hardware store and match up the threads and diameter with a cast iron or steel pipe plug.

Yeah, and then let us know what size it was, lol...





I always thought they were 3/4"....

 

[Swims350]

we did that very thing on the 84 used bolts in the air tube holes.

now on my 88 that did not work, one big hole in the front and it was like 1 inch dia. or so maybe 7/8 or something.

I want to say the bolts are like 1/2 maybe 7/16 or so.

 

[chengny]

im trying to take off the air pump and related smog equipment in preparation for headers

Not sure that we are reading this right.

If you're eliminating your stock manifolds (assuming that they're the stainless shaped tubing type - with 4 bosses to accept the AIR pipes) and replacing them with headers, where do you want to install a plug(s)?

If you pull your EPA stuff (i.e. air pumps, diverter valves, EFE valve, associated hoses, injection pipes, etc) and just run with headers bolted to the cylinder heads - you'll have a motor with the exhaust attached.

There would be no place to put any plugs.

Maybe what you're thinking about is a situation where the entire AIR system is removed but the factory manifolds are left in place. In that case, you need to plug the weld-o-lets on the manifolds - the bosses where the injection pipes were screwed into.

But, since you will be removing the stock manifolds, there isn't any need for plugs - there would be no place to put them.

 

[guitarfreak235]

im trying to take off the air pump and related smog equipment in preparation for headers

Not sure that we are reading this right.

If you're eliminating your stock manifolds (assuming that they're the stainless shaped tubing type - with 4 bosses to accept the AIR pipes) and replacing them with headers, where do you want to install a plug(s)?

If you pull your EPA stuff (i.e. air pumps, diverter valves, EFE valve, associated hoses, injection pipes, etc) and just run with headers bolted to the cylinder heads - you'll have a motor with the exhaust attached.

There would be no place to put any plugs.

Maybe what you're thinking about is a situation where the entire AIR system is removed but the factory manifolds are left in place. In that case, you need to plug the weld-o-lets on the manifolds - the bosses where the injection pipes were screwed into.

But, since you will be removing the stock manifolds, there isn't any need for plugs - there would be no place to put them.

maybe i should further explain myself, this is my daily driver and my only car, so i am removing all of this now, even though im gonna do headers. i am just trying to make the headers/exhaust upgrade as quick as possible because i need the truck eveyday. this way i dont have to fool with the smog stuff the day i do the headers. besides id like to clean up the engine bay now anyway

 

[chengny]

Ah-hah - now I get it.

Go ahead and pull everything out - except the injection manifolds and the check valves. You can leave them attached to the exhaust manifolds for now and just pull the entire assembly when you are ready to switch to headers.

Those check valves are extremely reliable. I've never found one stuck open.

With the air pumps (also diverter valves, brackets, associated hoses and decel valve) gone, you'll be left with a nice open engine compartment.

When you start up for the first time after decomissioning the AIR system do this:

Rev the engine and put your hand over what used to be the pressurized air inlet to the check valve. If the check valve is tight you won't feel any exhaust back feeding through it.

Don't check it at idle - it won't be a good test. Because there are no catalytic converters on these trucks and due to the capacity of the dual 2 1/2" exhausts, the venturi effect of the exhaust gasses causes the manifolds run under a slight vacuum at low engine load. As a test, remove the belts from the air pumps. You'll see that they actually rotate (slowly) as air is sucked through them and over to the manifolds.

If one does leak, just cut off a section of the old hose. Clamp one end to the check valve inlet and screw a 1" NPT pipe plug into the other end.