1980 F350, 300 6.....There is a pipe that goes from the intake to exhaust. The fittings are stuck. Can't figure out what size the fitting is either. 1 1/8 is too small. 1 1/4 is too big. Could it be 1 3/16, if so can't find anyone who makes a wrench that size? Have tried a pipe wrench with a 3 foot pipe on the handle and can't break it loose. Don't have access to a torch to heat it. Any ideas?

 

PB Blaster or Kroil. I've got the same thing on my 1985 F150, 4.9L. I changed it a few years back, but I had to change the exhaust manifold gasket too. So, I removed it and replaced them both at the same time. I really don't remember what size or tool I used. I do remember that I got really frustrated putting it back on and had to get my wife to help me (both fittings had to be threaded in simultaneously).

 

The 300 has a gasket between the intake and exhaust manifold. The only way to change it is to get one end of that pipe loose. I can't afford to take it to a shop. I wonder if a small propane torch would heat it enough to loosen it?

 

That woulkd be a possibility, although I used some PB Blaster (alot of it). Oh yeah, and a cheater bar.

 

That is the EGR Valve Crossover pipe.

They are indeed a pain. Use PB Blaster or any other type of penetrating oil to loosen them. When you reinstall it, use some anti seize lubricant on the fittings.

If it's really welded together, only thing to do will be to take the manifolds off the head.

 

Taking the manifold off the head won't accomplish anything. There is a gasket between the exhaust and intake manifolds that needs to be changed. They have to be seperated by at least 3 " to change this gasket because of studs. The only way to accomplish that is to pull at least one end of the pipe loose. So even when I pull the manifolds off, I won't have enough clearance.

 

I have to beg the question, are you replacing the spacer to manifold gasket, or the exaust to intake manifold gasket? If you are replacing just the spacer to manifold gasket, you are right, you just need to loosen the one fitting to gain clearance.

If you are changing the exaust to intake manifold gasket, you have to remove the intake and exaust manifold from the engine, no way around it.

However, You will have enough clearence to get a better grip at the pipe fittings with the manifolds off the engine.

To change the gasket between the exaust and intake manifolds, where they connect together (The small manifold gasket below the carb spacer where the two manifolds connect) the manifolds need to be seperated, and to do that the manifolds need to be loosened and removed from the head and a new intake manifold gasket installed.

1: Remove the carb

2: Unbolt the intake and exaust manifolds, remove from engine.

3: Loosen the EGR pipe fitting at the carb spacer or intake manifold (depending on calibration), or at the exaust manifold.

4: remove the carb spacer, and the bolts and nuts holding the two manifolds together, seperate them.

5: Check the intake manifold and exaust manifold for cracks. Especially where the heat from the exaust manifold touches the intake manifold when the heat riser spring is open.

6: replace the gasket that goes between the two manifolds, and put the two manifolds back together, but do not tighten them yet. Hook up the EGR tube and replace the spacer to manifold gasket.

7: Put a new intake manifold gasket on the engine, and line up the manifolds and torque them down to specs.

8: tighten where the two manifolds hook together to the proper torque.

9: replace the carb to spacer gasket, and bolt up the carb.