As the title says the air pipe has a heavy leak where the lateral from the 6th cylinder exhaust attaches to the main pipe. I couldn't see the spot but it felt like a crappy weld/braze job from the factory gave out.

Has anyone had any success with any kind of epoxy/putty? I've read some threads and the prospects of that working seem dim. I figure there's just too much vibration and thermal expansion/contraction at that point since it seems to be a common failure point.

Aside from that the only other options seem to be replacing or deleting. I'd like to keep the system stock since I don't really have any reason to delete it. All else fails I can just grab a dubious aftermarket pipe online and start soaking the ferrules in pb blaster now... Might be a nice opportunity to stick a new valve cover gasket on and give the cover a nice coat of enamel.

Has anyone tried/heard of anyone removing the pipe without removing the upper manifold? Seemed like it might be possible, but it would probably turn an hour job into a four job to weasel it out of there.

May have started to ramble a bit here. Really I'm just fishing for some ideas or some direction from someone who has fixed their air pipe.

 

Yes, I've tried doing that with the intake on. Cylinders 2-5 came out with a light bite from a tongue & groove plier. 1 and 6 required removing the plenum and a bunch of other stuff, then 2 hours of hammering, drilling, and chiseling.

Highly recommend giving it a try with the plenum on, doesn't cost anything and there's a nonzero chance you'll get all 6 out.

Removing the assembly afterward was none of my concern, I cut it into a dozen pieces and it has been replaced with bolts. So I can't give ya any advice there.

 

Pull the plenum, not that hard.

Yes do a fresh cover gasket, Felpro's unit is nice. VHT makes Ford Industrial Grey paint too. I recommend having your fuel injectors serviced while access is easy.

As for me, all my vac lines for smog were broken and since truck is exempt from tests, I just removed all that stuff. I left the TAB/TAD plus the EVR in place and connected. This also includes removal of that AIR pipe. Buried within my build thread is the place that sells plugs to fill those holes.

Of course yours being OBD2 will toss codes with that stuff defeated. You might have that EGR pressure differential sensor too.

 

That might be geography-dependent. Here in the Northeast, I've pulled about 5 of these 4.9 manifolds, and every one was a 4+ hour job due to stuck bolts. Two of them were over 6 hours. Plus the cost of whatever parts break on their way out.

You're right tho, cuz on one of them I had to pull it a second time, and the second time was a ~20 minute affair.

OP, where are you located?

 

I’m in Texas so it probably won’t give me that much trouble to remove.

I may try to braze it myself once I get around to taking it out. From what aftermarket I’ve seen on this part the quality is very underwhelming so I figure that’s the best course of action. I looked around a little and I couldn’t find anyone else posting about trying that so it should be a nice experiment to see if it works. If I can manage to braze pretty much anyone could.

 

I too am in Texas. Where?

Maybe can lend a hand

 

I'm around the Waco area.

I may go to the junkyard and see if there's any 300's there that are mostly whole. Odds of an intact air pipe to use as a backup being there are slim but not zero.