Best way to take off rusty manifold???

B

benracin

New member
Howdy guys, I need to take the head off my 89 E350 and the bolts on the exhaust manifold are really rusty. I'm basically worried that I'm going to be breaking bolts all over the place and having a really really bad time. I've already broken off a tap in the head which is why I've got to take that head off. I've been hosing it down with some bolt loosener stuff, any tips out there on how to get this thing off?
 
Heat is your friend for stuff like this. Get a oxy torch with a small tip so you can control the flame and keep it in a small area.

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Doug Hillmann
 
Shouldn't you be on your honeymoon?

PB Blaster. Hose it down, wait, hose it down, wait, repeat. If that fails, then heat, spray with PB Blaster (yes, it makes a little fire, but), repeat. The last method has never, ever failed me for getting out a stuck fastener.

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Bill
Planet 6 Racing
bill (at) planet6racing (dot) com
 
If you have to take the head off & deal w/ the broken tap, why not just deal w/ broken studs too? If they are that rusty, they probably need to be replaced? I've seen people just get on it w/ the impact gun, break it or remove it is the same result - manifold is off head goes to the machine shop.

Otherwise heat it until its dull orange.
 
Now we're talking about heating the bolts right? I've done this on other stuff, but maybe you guys could explain it to me. Wouldn't heating the bolt cause the bolt to expand, making it a tighter fit in the hole? Or am I smoking crack and I should be heating the head instead. I'm guessing the bolt because heating the head is a lot of thick metal to heat.

Just got back from the honeymoon in fact! I've got a lot of van and car work to do if I want to get my first race in this august. It's funny how fast your mind changes once you get all that wedding stuff taken care of. Now I can get back to the important stuff.
smile.gif


I guess I need to add this: "if she'll let me" since I'm married now.
 
Oh! I know! Is it Pie - 1!!?? I have no idea.

So does the head or the bolt get the fire? Something is going to get toasted on this engine!
 
Ben:

The heat goes to the bolt. The differential temperature causes the bolt to expand, essentially crushing the corrosion. After it all cools, the corrosion should theoretically be broken free and the bolt should come out. I like to hit it while still hot with the spray penetrant (PB Blaster) because it seems to wick in quicker and the hot gases force stuff out (maybe, not real sure, but always seems to work).

August race at Road America?

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Bill
Planet 6 Racing
bill (at) planet6racing (dot) com
 
Yep, that's the race I'm working towards, and so should you too!

So should I let the bolt cool before going at it or just try working on it while it's hot?
 
If you have got to start asking the theory and physics of using a "hot wrench", you will continue to break the studs...

Just try it. Afterall, you already have at least one broken stud.

CHEERS
 
After you use the heat and pb blaster or whatever--hit the bolts with a brass hammer to shock them. If you hit them straight and watch the threads it will just spin out. I have a brass insert in my air chisel that works wonders. Breaks all the rust loose in the hole.
 
See, this is good stuff. And I've used the old hot wrench before, I just wanted to know what worked for other people out there. Breaking bolts is getting a little old so I wanted to try something new.

Got some PB Blaster last night and I've started soaking bolts. I kind of doubt this is going to help get out the broken tap I have lodged in a bolt hole since it's not really held there by rust, but we'll see! If I can get that p.o.s out I can leave the exhaust manifold just the way it is. Cross your fingers!
 
I had never heard of smacking the hot bolt to loosen the rust. Good idea. I assume the brass hammer head is to keep from peening over the threads.

I have also heard that the heating of the whole mess has an effect on the rust itself and causes it to change chemically or crystal structure wise such that it bonds less and becomes more slipery. (Kind of like graphite slides on itself.) I have never seen this demonstrated or written down, it only came from my uncle who is a wizard on the physics behind how & why things work.
 
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