I have a 1987 LT with carburated 305 motor. One of the cooling lines going to the firewall is T'd off and has a smaller line going to a hose barb fitting that threads into the back of the intake manifold, behind the carb. I've been unable to find anywhere defining what the purpose of this line is. Most pictures I've seen have a bolt in the manifold. My issue is that the fitting broke off and I need to get the remainder out (mostly the threads) of the intake without dropping any pieces into the manifold. I've seen many videos of a similar issue on newer engines but these are much bigger fittings (mine has a 3/8 hose barb) and seem to be on the side of the manifold, not the back. Any suggestions on how to remove without pulling the manifold and everything that goes along with that? I've been to the autoparts store and looked online and no where have I found this part identified other than by eyeballing it.

 

My guess is that it was a port for other makes like a truck for the heater hose... maybe someone just tapped into it?

My best hhope would be to try putting some pliers or something in there. open it and see if you can turn the fitting with the pliers opened and extract it.

 

Post a picture it might help

 

Here's where the fitting broke off, behind the carb, and beside the distributor cap which you can see on the right.

 

oh.. that looks pretty bad....

 

Purchase an easy out. watch some vids on it, go real slow and easy. Had to do the same with a brass oil pressure fitting for a sender by the dizzy. They work if your patient.

 

Heat and penetrating oil. Can't get too hot because the intake is probably aluminum (low melt temp). Might get it out with an extractor.

The other way to go is to clean it up so you can see what you're working with, drill most of the old fitting out, then pick the threads out of the intake. Alternatively, drill it all out, oversizing the hole, tap, and install a new fitting or plug.

 

Those fittings always go bad that way. It's inevitable. Has to do with the metal they're made out of, and being screwed into aluminum.

I've seen them fixed before by drilling out very carefully, then using a dental pick or whatever to pick as much of the remains out of the aluminum threads as possible, then running a 3/8" NPT tap down in it to clean whatever is left out of the threads. I've also seen them drilled & tapped to ½" NPT, which is probably what I'd do.

Don't think I'd try either with the intake still on the motor.

Your description of what's associated with the hole sounds like Stimpy has already been there. Should have been nothing but a 5/8" hose barb with 3/8" NPT threads. It's the hot water supply to the heater core. The other line at the heater core is ¾", and is the return from the heater to the cold side of the system. Goes to either the cold tank of the radiator or the water pump body. More likely the rad in a 87.