i was in process of replacing manifold/downpipe gaskets today on my 86 4x4 pickup.

2 of the studs came out with the bolt, neither look reusable.

1 stayed in. The blind hole. it was so corroded on it wouldn't budge. I did a few tries of PBlaster and heated up with torch. Then I gave up and took pipe wrench which moved a slight amount before snapping.

I am assuming it's going to be impossible to remove the bolt. Don't think ez out will have enough torque, and since it's blind hole, im thinking its going to be too difficult to drill out as well.

I'm leaning towards just buying the cheap dorman exhaust kit off amazon.



what do you guys think?

 

Is that in the manifold or the downpipe I can't tell? And you can probably get a header for the price of a new manifold just saying lol

 

This is one of those things taking it off to fix this the correct way

Drilling the bolt out repairing the threads by either thread replacement or going larger .A drill press is a given as well as being able to clamp the manifold in a straight and secure way

It would be faster to just replace the manifold

 

argh, i just realized that since the Dorman manifold is technically an "aftermarket" manifold. I'm not sure if it would pass CA Smog visual inspection. maybe... not sure how thoroughly they would check. the one i took off says "made in usa", so i wonder if that was aftermarket as well, or made by toyota in the US.

I supposed drilling out to next size tap would be best bet.

and yeah, that's the manifold. not the downpipe.

 

If you heated with a torch good luck drilling it out. You hardened the piss out of it by putting the torch on it. Most drill bits will have trouble drilling it

 

Try a 50/50 mixture of acetone and ATF. I've had great results compared to many other products. Use a punch and whack it a few times after the stuff has a chance to soak, then use an easy out.

 

word. unless you have some damn nice drill bits, you'll give up on trying to drill it out. if you have an oxy-acetyline torch you can try and blow the old bolt out and then see if you can save the threads or step up a size.

 

Try drilling it out. You have nothing to lose.
Start with a pilot in the center and then use a bit small enough to not damage the threads.
An easy out or small chisel may then work and you could still use the same size stud.

 

If you have a mig welder,carefully hit the center of that with a few little blips of weld until you have a little raised dome,you need steady hands,don't weld the what's left of the bolt to the manifold. Then get the next size bigger nut and center it with the dome in the center of the nut. Set mig welder on a higher setting and start with the center of the dome and weld the hell out of it till the weld has filled up to the top of the nut. Don't burn the nut up. While it's still hot,get it glowing orange with the torch and start soaking it with water right away until it's completely cooled down. Then carefully try to unscrew it with a wrench. Sometimes this takes several attempts repeating this same process.

 

I feel your frustration. Last month I was taking apart some equipment at work and had 2 bolts snap off in a significantly worse location - like up against the wall of the machine, so can't even get a drill to go in straight, let alone get any other hand tool in there.

Anyways, I suggest you try reverse drill bits before trying an easy out. I had an easy out break on me when trying to remove the broken bolt - NOT fun to deal with that.

If you have a mig welder, I'd try taking a washer and weld through the center of it, onto the broken bolt. Then take a nut and weld the inside of that to the washer. Hopefully the heat from this will have broken it loose and you can now use a wrench. That's the next attempt I'm gonna try on my equipment, I've got 12 more bolts that need to come out and they have no heads on them, worn off from 50yrs of clay abrasion

Good luck!