pwsusi

This may be a stupid question, but what's the best way to remove a set of exhaust manifold plugs? It looks like a 1/4'' rachet fits but there is a little play and i'm afraid of stripping them and causing a bigger problem. I wasn't sure if a Robertson bit would be better?

Greg

Put some heat on them first and they'll come out easy, or else the center will probably round out.

pwsusi

Thanks. So sounds like 1/4'' rachet is the right tool? One is already slightly rounded and i'm afraid to mess with it.

leadfoot4

Apply some heat to the manifold itself, then drip some candle wax into the threads of the plug, while it's hot. The wax will wick down into the threads, and help the plug unscrew.


(I'm serious!!)

DUB

I use this method A LOT!

Also using some valve lapping compound on the tool you install into this plug will also aid in filling in any voids and provide added grip. I use it when i am removing Allen head set screws.

DUB

bmotojoe

Get that plug red hot, just don't drip some wax on it, stab the large end of the candle right on the plug for a second or two.

DUB

??? Maybe you do it differently than I do but I see that there is no reason to get the plug red hot.

Actually the way I do it is to heat up the cast iron quickly so it can expand slightly BEFORE the plug can expand.

DUB

68notray

Yes, per Dub, quickly heat the casting around the plug but not the plug itself. You want as big a temperature differential as you can get. Heating slowly gets everything hot and gets you nowhere. Another tip is to rap the plug with a hammer first to shock and separate the threads.

fede

I've never heard about the wax thing...
What's the difference with using some penetrating oil or other lubricant? Same result?

cor66vette

dmaxx3500

and use a real torch[welding ],heat the manifold up and stick a large candle in it,,we used that to take out plugs in eng blocks ,before cleaning them

Cavu2u

The wax thing is interesting!
I'd love to know who and how it was First discovered.

Here's what I've had real good results with.

Steve

stingr69

Similar problem - Those threaded block plugs are basically impossible to get out unless you use an oxy acetylene torch to heat it cherry red then spray it with PB Blaster. They will almost unscrew themselves at that point. Kind of fun once you know how to do it.

DUB

I see we all have methods that we prefer. I still do not like to heat up the melt to cherry red...but whatever works I guess.

I do agree with shocking the part by tapping on it to help break any tension. I have also heated it up and immediately cooled it with a water soaked towel to shock it also....then heat again.

Also...check this out: Look at the results in the first post.

https://www.garagejournal.com/forum/...d.php?t=182271

I have stopped buying penetrating oils and make my own using a 50/50 mix of ATF and acetone. Just another option. YES it works.

DUB

cor66vette

Cavemen