1973 472 exhaust manifold bolts ?

[Morella]

I ended up unbolting that triangle shaped thing and can get to the bolts now and one came loose with the impact but the others will not budge

Triangle-shaped thing? The upper control arm? I don't see any clearance problem with those bolts in the photos...if you can't get a socket and breaker bar on them, just use a pro-quality box end wrench and a cheater bar, piece of pipe or whatever. If you're not familiar with removing broken bolts, don't remove an exhaust manifold (I've forgotten why you're removing them).

-d

[Paradox]

If you look at the first picture I can't get a socket on them. I don't have any 6 point wrenches to use. I am removing them because 2 are broken off and I have basically open engine on that side of the block. Very loud in a bad way.

[spastic_chicken]

I'd use a box end wrench. I rarely use universal sockets for much, they break too easy.

[spastic_chicken]

And soak those fuckers in liquid wrench or penetrating fluid for DAYS before you even try to break them loose.

[Paradox]

I have 6 point impact sockets and a craftsman prof. impact and it won't budge. I even tried the cheater bar on a ratchet. I don't think a wrench will budge either but I'll try.

Been soaked in PB blaster for a good week.

[Paradox]

two more just broke off. All the 9/16 wrenches I have will round off the bolt heads. I have like 5 different brands and none will work.

[spastic_chicken]

You are going to have to soak the shit out of them with penetrating fluid for DAYS... It also helps to heat the bolts so they are red hot, and let them fully cool. In between soaking them with penetrating fluid. If you don't do this, you'll just keep breaking them off. Break too many of them off, and you'll have to pull the head and have it sent to the machine shop to get them out. If an end wrench is breaking the heads off, using a universal isn't going to make it any better.

[Paradox]

I soaked them for a week. I don't have a way of getting them red hot I only have a heat gun. The impact gun only got one loose the rest I had to do with hand tools. I got 3 out and the rest broke. The manifold is still attached somehow though. If I have to pull the head to get the manifold off are the headbolts reusable and is the gasket reusable?

[Morella]

Sometimes head bolts are reusable, sometimes they are not. If they're not rusted, and they will hold the rated torque when you tighten them, which, if memory serves correctly, is 105, but double-check that, they'll be OK. You will need a head gasket set, and you should check for warpage of the deck and the head, which, I believe, is outlined in the service manual.

-d

[Paradox]

I don't have any of the service info for this yet. I need to see if they have a downloadable one for this.

[pyro]

Some folks insist on using stainless steel bolts to solve the rusted bolt problem. The stainless steel bolts are grade 2 bolts. GM used grade 5 & grade 8 bolts only. Its gonna suck, but pull the heads for all the broke bolts.

[Paradox]

I can't pull the heads on this because I can't afford the new gaskets and head bolts right now.

Well this has to be the most time I have ever spent on any one specific problem. I still don't have it off but the manifold moves a fair amount more.

[Paradox]

After a couple weeks working on and off I got it. I had 2 mechanic friends look at it and fail too. Below is all it took.

Broken/used
5 bolts
2 cans of pb blaster
4 drill bits
3 broken bolt extractors
2 hacksaw blades
DAYS OF MY LIFE!

Used but still alive
sledge hammer
drill
drill press
crowbar
metal bar/ punch
air chisel / impact

I still have the 5 bolts that are broken off inside the head to go but the manifold is off.







Should I remove what i guess is the head bolt before drilling out the bolts stuck in the head? Do they go up against each other? See below.

[Morella]

Should I remove what i guess is the head bolt before drilling out the bolts stuck in the head? Do they go up against each other?

No, and no. Just don't drill too deep. Use a stop, or wrap masking tape around the drill bit to limit its depth.

Don't drill too large, and don't let the drill bit to crooked, or you will damage the threads. Removing bolts is a precise operation which requires experience.

-d

[spastic_chicken]

I may sound like a pansy, but this has happened to me in the past, and I just bring the pile of parts to the machine shop and let them take care of it. It can be done just like Morella says, but there are times I've tried it myself and made the problem worse and ended up having to take them to the machine shop anyway. The cost for them to do it is pretty low. So you have a couple options.