I'm sure this topic has been covered many times before...but I am lazy on the searching tonight.

I need to remove the exhaust on an 85 GT. What is the best way to remove the two bolts that connect it to the Y-pipe without breaking them?

Obviously I will soak them for a week with PB Blaster first. I will hit what is exposed on the back of the bolt with a wire brush to clean them up as much as I can. A couple things I am considering....

Impact gun or hand tools? Impact gun sounds easy....but is it more likely to break the bolt than a hand tool?

Heat....good or bad here? If I use a torch, is PB Blaster flammable? Do I heat the bolt, the metal around it, or both?

What about cutting the back of the bolt? I could cut the bolt with a cut-off wheel on the Dremel...cut it right behind the nut on the Y-pipe. Then I only have to remove the bolt the distance of the nut rather than running the rest of the bolt through it. Will the potential rough edge of the cut be worse than the rest of the bolt?

If I do break this bolt....can I just drill it out and use a standard nut behind the one welded to the Y-pipe?

I've had good luck using the impact gun on an "extremely low torque setting".

I have an air gun, and dial it down to where it's just barely ratcheting. I usually cycle it loosen than tighten, rocking back and forth. This seems to help break the bolts free. (Similar to tapping on the bolts to breaking the rust bonds).

It usually ends up breaking the bolt free, or breaking off the bolt head!

Good luck, Marc

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Marc in sunny Titusville, FL

• 84 SE son's car, loaded
  
• 85 Coup w/V6 transplant
  
• 85 GT newly on the road
  
• 86 SE/GT "The Chameleon" - big plans!

I wouldn't worry too much about them. I would just try to get them free and if they don't come out, let them break and just drill out the bolt/nut that is left on the manifold. Replace with a stainless steal bolt and friction locking nut (not the nylon insert type).

J.

PB Blaster is your friend
spray all the nuts and bolts with it, let it set for a day and then go after it.
Good luck!
D.

quote Originally posted by jaskispyder: I wouldn't worry too much about them. I would just try to get them free and if they don't come out, let them break and just drill out the bolt/nut that is left on the manifold. Replace with a stainless steal bolt and friction locking nut (not the nylon insert type). J.

yup. tho - you can get the actual proper bolts from GM. they have a special anti-seize compound on them.

Clean them. soak them. take a torch and heat the nuts up a few times to allow expansion and contraction for the oil to soak in further.

If all else fails break the bolts off, cut them flush with the nut on then remove them from the sub of the bolt sticking out from the back of the nut.

work them back and forth by hand a little bit each way. There tiny, so they will break easy. Recommend you replace them if they look any bit questionable with higher grade or stainless ones for next time. Saturn studs fit perfectly and are much better than stock ones.

quote Originally posted by rogergarrison: work them back and forth by hand a little bit each way. There tiny, so they will break easy. Recommend you replace them if they look any bit questionable with higher grade or stainless ones for next time. Saturn studs fit perfectly and are much better than stock ones.

The saturn studs won't work, as he was talking about the manifold to y-pipe connection (I believe)
J.

Just soak them in penetrant ,,then brush any threads that protrude,I keep old hard tooth brushes,I cut bristles in half.. Take the time to clean exposed threads ,,you can jack up passeger side,,hang,em high,,this will assist penetrant in downward flo ..The stuff will just not flo properly, unless at a downward angle,,I,ve checked !!
For what I think will be stubborn bolts ..I hold something under the bolt threads while I spray to obtain a buildup or puddle to assist flow...If it is really rusty and I think I may have a serious problem..I will drill a hole in a soda bottle cap(tight fit), place it over the nasty bolt,, sometimes I attach it in some manner so the penetrant puddles up..doing this sort of thing is much shorter time wise ,than extraction..

I had a difficult time with one of mine, an evil spirit was living in it

[This message has been edited by uhlanstan (edited 01-29-2010).]

quote Originally posted by Hank is Here: Clean them. soak them. take a torch and heat the nuts up a few times to allow expansion and contraction for the oil to soak in further. If all else fails break the bolts off, cut them flush with the nut on then remove them from the sub of the bolt sticking out from the back of the nut.

Exactly.

I had mine cherry red from MAP gas and quenched them down with the PB Blaster (fire extinguisher at the ready) and repeated a couple of times. On my other Fiero, I just took a cut off wheel and cut them off, paid the nice man at the machine shop to extract them along with the welding and sand the mating surfaces flat on the manifolds.

There's something about working with fire that gets to me on a deep primal level, besides, it's fun.

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jetman
Silver 86 SE 2M6 4-speed, with "check wallet light"
Now fortified with 8 essential slices of bacon goodness

My mistake, carry on

Wanted to come back and thank everyone for their advice.

I sprayed them from the back with PB blaster every night for 6 nights. Sprayed it from the top, which allowed it to soak in nicely. I intended to hit it with a wire brush....but....chalk it up to lack of work space or just laziness (often the same thing), but it didn't happen. Hit them with the impact gun. IR Titanium series @ 40 psi. That banged on it a bit, but didn't accomplish anything. Upped it to 90 psi....eased into the trigger. Both of them came out smooth and clean. Not sure why I thought this was going to be difficult. I intend to replace with new bolts.

Moral of the story: Air tools are a gift from the Gods. You know those 6 days that the PB Blaster soaked the part? Yeah....that is a perfect time to build an air supply system in the garage.

Hey, you're on a roll. Try taking the exhaust manifold bolts out of the heads now!

Best to have two people when doing this. Heat the nuts cherry red with a MAP/Oxygen torch. When they are glowing red, have your assistant turn them out with his socket wrench (6 point socket) They will come out with a very reasonable, not heavy, force. And they will squeak loudly at first. You might have to start by working them back in forth, tighter and loser till they spin more freely. Work them back and forth to the point that they turn hard. You will get a bit more travel with each reversal. You may need to add more heat if they cool before you get the bolts all the way out. Watch out, both the bolts and the sockets will be hot for a while after you get the bolts out. Don't even think of even giving them a slap to move them untill they cool.