and now, the exhaust manifolds.....

[4x4orbust]

are rusted on.   I have been spraying it with pb blaster daily for the past 3 days, and tried to remove the bolts.  they are rusted on like you wouldn't believe.   I tapped them with a hammer, heated it with a torch (tho never longer than 30 seconds) and pried as hard as i could on a 3/8 ratchet.  no dice.   it seems the head of the bolt is rusted to the manifold, can't see the seam from bolt head to manifold...

what else can i do to remove these bolts?  I have tried heating them, but i only put the torch to them for 30 seconds at a time,  (only on the bolt head, i may be doing it wrong) and tried removing the bolt in between heating.   more pb blaster?  harder blows of the hammer??  throw a breaker bar on them and hope they don't snap?

'thanks!!

phil

as mentioned in other threads, i have a donor truck that, if need be, i can take the heads off and put them on here, but that is an extreme last resort.... 

[frogman68]

Are you keeping the manifolds ?

If not grind the heads off then you will be able to get the PB on the threads then use a pair of vice grips

[Blazin]

Heat the manifold. You want to expand the metal surrounding the bolts. By heating the bolts you are expanding them and they are already stuck in the manifold. Heat all around the bolt area to cherry red. If that doesn't work torch the heads of the bolts off, slide the mainfolds off then you can heat the head around the bolt, and use Vise Grips to spin them out. Better to cut the head off, than break them trying to remove them. They will most likely break flush with the head. Then you will be looking at drilling and re taping.

[VileZambonie]

Use a breaker bar and try working the bolt free. Sharp blows will either strip the head or snap the bolt. Make sure it doesn't have the metal locking tabs on the bolts too. 30 seconds of heat won't do much.

[4x4orbust]

thanks for the replies,

i am not keeping the manifolds,  i am doing this to put headers on, not sure if they will be long tube or short tube yet....

i was a little nervous about heating the manifolds up (even tho they heat up a lot when driving) because i wasn't sure if there were any gaskets or something that would melt.  i will attempt heating them more tomorrow, i just sprayed them down with some more pb blaster today.  how long does it take to heat them up to cherry red??

i would hate to snap any of these, after my experience with my transmission pan, the last thing i want to do is drill and tap more holes....  one of the bolt heads already stripped, but i have some of these to grab the stripped head.  http://www.amazon.com/gp/product/B0000CCXVZ  they work pretty good too!!