4.9 Air Injection Tube Install on Head
 

I'm in the middle of a head replacement on a 1995 F-150 4.9, 5-speed, 2WD and am confused as to how the new air injection pipes attach. I bought new pipes F5TZ-9B445-B and 6 new union nuts E7TZ-9B471-A from Ford before I realized PCI sells them for a lot less. Do the nuts somehow crimp to the pipes as you tighten them? The pipes are smooth all the way down and there seems to be nothing to hold them to the union bolts or seal them. I've got the 1994 Volume 1 and 2 Helm shop manuals for Engine and Body but not the Emissions book. All it says is remove and install. Very helpful!

I've searched and found lots of info on how the air pipes don't come off in one piece and rust out but none on installation. I'd like to get these on before I torque the reman head down just in case something goes wrong. I'd also like to know what I'm doing before I damage $400 worth of parts.

Ford OE Replacement A.I.R. Manifold Tubes is the cost effective version of the pipes should anyone else need them. Their main page appears to have all of them from 1976-1996(7) for all the gas engines.

If I remember correctly the ferules do seal themselves to the pipe, something like a brass compression pipe fitting. If you look in the hole in the head for the ferule it should taper at the end of the threads and the end of the ferule should have a taper also. Make sure the pipe with the ferule is all the way into the hole in the head as far as it will go before you tighten the ferule. ou might want to get a tap and clean out the threads. Don't quote me on this but I think the thread is 9/16 by ?-- it was some time ago I did this and I just went to my tap collection and found the correct tap.

Going on what you say and looking at the ferrules, I believe you are correct. I'm not much of a plumber so I really didn't know what I was looking at. The pipe will bottom on the ferrule. This also explains whey the whole dumb setup is almost never reusable.

I ended up with an ATK reman head so everything is nice and clean on it. The original head was cracked on top of the #4 cylinder. Not the combustion chamber, but on the upper, oil side. I was surprised as I just thought it was a head gasket issue from poor cooling system maintenance. I had long suspected an issue but finally caught it with oil analysis.

After 2 more hours of searching and finally hitting the right key words I found another thread that agrees with what you say.

https://www.ford-trucks.com/forums/2...ctor-tube.html