broken exhaust manifold bolts

[84CUCV]

this is on a 87 454 if it matters. the exhaust is about to fall of the truck. we cut it all off. since we were there he wanted to put headers on. so far 3 bolts broke right off. this is on one side.
how do we get the broken ones out? second how do we keep from breaking the rest?

any ideas? thanks

 

[dhcomp]

Getting the broken ones out sucks, ill let more experienced ppl give suggetsions.

In terms of getting the rest out, try this. Hit all with Penetrating oil for a few days.

Then, put a wrench on the bolt, and tap the end with a hammer lightly, a few hits in teh "tighter" direction, a few in the "looser" Direction, repeat. Each time hitting a little harder. Then, when you are confident you have broken up all the crap that might be holding the bolt, remove it. Worked on my burb! but it was a CA truck.

 

[84CUCV]

we did get Penetrating oil on it for a few days. Do things really rust in CA?

 

[4X4HIGH]

I successfully drill broken bolts all day long. The biggest mistake people make is not center punching the bolt and also not drilling COMPLETELY through the bolt. Once it is center punched then drill a 3/16" hole (squarely) completely through the bolt then step up in size until there is only a shell of the bolt left THEN you may try an EZ-out. I like the square EZ-outs the best, they tend to be stronger and less brittle. Worst case scenerio is that you have to heli coil the bolt hole.

 

[84CUCV]

great thanks

 

[dhcomp]

Which bolt locations broke? I've successfully drilled out bolts also, and as usual, 4x4high's directions are spot on. But it is easier said than done on the rear half of the bolts.

 

[84CUCV]

the hard one will be the one all the way in the back

 

[80' 427]

If there is any stuck out you can heat them bright red with a torch, squirt pentrating oil on them. Then let them sit and they will come out. Broken off flush is different but if you have a left handed drill bit sometimes they jump right out.

 

[84CUCV]

one has a bit stuck out.

 

[sweetk30]

next size bigger nut over broken bolt. then plug weld the nut to the broken bolt. let cool. then try it. if not heat the area up and then drench in cold water. try it.

sometimes it takes 2-3 nuts to get them out. worst case drill and retap to clean up crap in threads.

i do this all the time up hear in the rust belt . saved me tons of time and money for repairs. even do it in the vehicle and save pulling the heads off the motor.

 

[84CUCV]

thanks