I am trying to get the heads off of my 460 EFI in my 95 f250. I've gotten everything off that I need to with the exception of the following items:

1. Secondary Air Tube (I think)- Metal tube attached to the rear of the drivers side exhaust manifold under the EGR tube. It's attached to the manifold with a rusted/seized compression style fitting. I have been soaking this fitting with a PB Blaster soaked shop rag for about a week. I've tried heating it, using some freeze off stuff, and a long wrench. I cannot get it to budge but I have not yet rounded it off.

2. I thought that I might be able to take the drivers side head/exhaust manifold off with the secondary air tube attached to it once I disconnected all the rubber hoses from the thermactor system on the passenger side, only to find that this same metal tube is welded to a bracket that is attached to the firewall side of the passenger cylinder head. I stopped here today, It's 20 degrees out and I am working in my driveway and was just frustrated enough to call it a day and check in with some of you guys.

The reason the exhaust manifolds are coming off with the heads is because about half of the manifold to head bolts are broken off and I am going to probably need to remove what's left of them from a bench in my garage.

I've read a lot about just removing the entire thermactor system on this site, but have read varying opinions on what the results would be. I'd be very happy to take my sawz-all to these air tubes, pull the heads, plug the holes, chop out my cat, get rid of the air pump, leave the TAD and TAB electrical connections intact, remove all the thermactor vacuum lines and put it all back together without having to worry about all that crap making it so hard to work under the hood.

Has there been any definitive answer as to whether eliminating this system would affect my fuel/air mix enough to throw a CEL? Would I just be able to put a pipe plug in the drivers side exhaust manifold where this air tube is currently coming out of?

I will never have to have emissions tested on the truck. I do not want to have a check engine light on as a result of deleting the thermactor system.

The main reason I am considering this is that I'll probably end up destroying some of the metal air tubes anyways as I can't even get them to budge. I can't seem to take the heads off until the air tubes are disconnected (right, or am I missing something stupid?), and I'm wasting a ton of time sitting out in the snow staring at these tubes instead of turning wrenches and getting back inside.

Any thoughts are appreciated. If it matters, I am in Illinois and '95 and older vehicles aren't called up for emissions.

Thanks

 

You can remove the thermactor system and not trigger a Check Engine Light as long as the TAB/TAD are still electrically connected. You will fail the KOER test, but there will be no lingering CEL.

A PO had removed all that on my current '92 F350 when I purchased it a few years ago. They even did me the "favor" of gutting that huge single converter that comes from the factory. I am not sure how the EGR is hooked up on your 7.5L engine, mine is a 5.8L, but I suggest you keep that intact.

 

Has nothing to do with your Thermactor system question but I do have some advice on getting the nuts loose. I have a buddy that read of this piece of advice in a forum for the vehicle he was working with. He swears by it, but in the engine compartment it may not be wise. Heat up the fitting, heat up the bottom of the fitting, after its good and hot take a candle and rub around it and let the wax coat the threads all the way to the bottom, (where the majority of the heat was), after that with the wax coating the threads, ideally it will break loose. I have never personally used it but my friend has and he swears by it. Think he tried that working with exhaust as well. The other piece of advice is Kroyil, I am unsure of all the places you can buy it, but what I can tell you is that you can buy it at HVAC supply houses, (not locke supply, they'll look at you like your crazy) if they dont have it, they can get it. That stuff, I have seen it personally do alot of amazing stuff, I usually alternate between using that and PB, I like PB but Kroyil works alot slower, and unlike PB it doesnt eat at the Rust, it is a oil that creeps, it will take a good day or two to work, so dont be impatient, spray it down periodically for a couple of days then try supplying the torque to it. Good luck

 

RLA2005- Nice truck. Thanks for the info. Must be nice to be able to get to your passenger side valve cover without all the garbage in the way. Do you know whether your PO installed a dummy pulley where the air pump was or just used a shorter belt?

Dkrowland81- Thanks for the tip. I might give that a try at the connection to the exhaust manifold just to see whether it works or not. That tip will definitely be useful in future projects.

I think I am leaning towards just eliminating all the smog stuff because without pulling the entire engine out (I have no hoist or stand), it is too difficult to loosen the air tubes' hardware without destroying them.

Once I've cut the air tubes off, I should be getting close to getting the heads off.

Anyone know if you need to remove the engine lifting hooks to separate the heads from the block? That looks like another nice good spot to give yourself crippling forearm craps while loosening bolts.

Thanks again guys!