Exhaust manifold issue

[SeaRay24Sorrento]

Ive got a pair of Merc exhaust manifolds for an '88 4.3l that have broken plastic drain/elbow fittings on the bottom. Anyone have any tips or tricks on getting the broken plastic theads out. They both are sheared off right at the base of the manifold. Seems brittle and well adhered to the metal threads, I don't want to mess up the female threads. Many thanks for all your postings and input so far, I've been learning alot from all of you.

 

[Haut Medoc]

Re: Exhaust manifold issue

An ez out should work....Get the biggest one close to the size of the opening...<br />Shouldn'd be hard to drill through plastic....JK

 

[mkast]

Re: Exhaust manifold issue

The plastic should break away from the threads if you take your time and use a small steel pin punch with a hammer. Remember, you're working with plastic, the hammer size should match the task.

 

[SeaRay24Sorrento]

Re: Exhaust manifold issue

Inside diameter of the broken plastic fitting is 3/4". My ez-out set only goes to 1/2" Maybe I'll check Harbor Freight for a bigger size. Any luck with any other approaches?

 

[Haut Medoc]

Re: Exhaust manifold issue

How about a hacksaw blade to cut through most of it is several places, then use a suitable punch...<br />As long as you don't get into the threads, you'll be ok......JK

 

[tashasdaddy]

Re: Exhaust manifold issue

the hack saw trick worked for me. it was brass fitting into the elbow. 3 cuts then a punch.

 

[SeaRay24Sorrento]

Re: Exhaust manifold issue

Well I got one side done. Tap,tap,pick,pick,chisel,pick,TORCH,pick,pick...TORCH. That plastic must have been loctited in! The torch helped to make it more brittle after I got it red hot (the plastic would not melt),then picked it out. Used a steel male threaded pipe fitting and cleaned the rest out like a tap. Don't think I'm going to use the new plastic fittings, I have a pair used bronze ones I think I'll use instead. Plastic sucks! Thanks for your input.

 

[Bondo]

Re: Exhaust manifold issue

Ayuh,........ Brass is the Only Way To Go.......... <br /><br />When I 1st heard about those Plastic drains,......... I figured they'd be a Problem............

 

[JIm Cook]

Re: Exhaust manifold issue

I am heeding Bondos words above and changing mine to<br />brass. Every fall I cringe when removing these<br />plastic pieces thinking that it's my turn to dig<br />them out after they break.

 

[crazy charlie]

Re: Exhaust manifold issue

Just spray carb cleaner on the plastic and you will be able to easily pick it right out, if it does not crumble and fall out by itself.