Broken manifold bolt

[jedgell]

The seal between the riser and manifold on my GT-40 has been leaking a little water lately, so I decided to replace the gasket. Of course the last bolt broke off, one of the long ones. So, my question is, how do I get the broken bolt out of the manifold. I'm thinking I can drill it and put in a reverse tap to get it out, but are there any other tricks? Should I heat it up? Just wondering, what's the best way to remove bolts like that, that haven't been moved in 12 years and have rust on them?
Thanks for your help.

[Andrew]

RE: Broken manifold bolt

if the bolt sits flush or above the top, u can weld the inside of a washer to the bolt and then weld a nut to the washer, then back it out with a wrench.

[Miljack]

RE: Broken manifold bolt

I'd be careful trying to get that bolt out of cast iron without some help. Soak it with a good penetrating oil, and use a torch to get the manifold hot, then try to grab it if you can with stud removal tool if you have one, vice grips as a last resort. If the bolt is below the surface, then you will have to resort to drilling. Just remember if you break an "easy out" in the manifold, it's probably game over for that manifold.
Jack

[TRDon]

RE: Broken manifold bolt

take it from me, I do a lot of work on cars and I have dealt with thi s a few times. Nothing was worse than when I broke an easy out in the bolt hole, at that point you cant drill it out cause the shtrngth of the easy out is better than the drill bit. Your best bet is to drill the bot out and tap it out new again if it is below the surface. If not try to soak with penetrant and heat it out.

[jedgell]

RE: Broken manifold bolt

The bolt is flush with the top surface, so I'll have to use an easy out, or drill it out. How do I go about drilling it out, without damaging the threads. I'm assuming you start with a small drill and work your way up, until you can get the bolt out.
In the future, how do I loosen these bolts without breaking them?

[M3Fan]

Re: RE: Broken manifold bolt

In the future, how do I loosen these bolts without breaking them?

Just be liberal with the anti-seize when you replace the bolts, which will make it easier next time. The torque on those is very low- about 24 ft/lbs so if you're expending large amounts of effort to un-do the bolts, then you're well over the 24 ft/lbs and should probably let it soak with penetrating oil before going any further with the wrench.

[Andrew]

Re: RE: Broken manifold bolt

The bolt is flush with the top surface, so I'll have to use an easy out, or drill it out. How do I go about drilling it out, without damaging the threads. I'm assuming you start with a small drill and work your way up, until you can get the bolt out.
In the future, how do I loosen these bolts without breaking them?

when loosening, don't use slow proggressive pressure, use short bursts. kinda "bounce" on the wrench with ur weight or use a hammer to tap the wrench around until loose.

[boatech]

RE: Re: RE: Broken manifold bolt

change riser gaskets more often and you wont have that problem!