That time a stuck injector on a Duramax in Flagstaff almost beat me

I was working on an L5P in a shop up in Flagstaff, and the number 7 injector was seized solid. My usual puller just bent. Out of ideas, I grabbed a can of penetrating oil and a heat gun, heated the area around it for a good five minutes, then tapped the puller with a small sledge. It popped free on the third hit. What's your go-to method for a truly stuck injector when the normal tools fail?

3 comments

3 Comments

hollyg591mo ago

Honestly, that method makes me nervous. Heating the head like that can cause real problems, like warping or cracking, especially on a diesel. In my experience, a better move is to let a good penetrant soak for days, not minutes, and use an injector puller with a real impact gun on a low setting. The vibration does the work without the heat risk.

sageross1mo agoMost Upvoted

Yeah, but you gotta get the heat right. A quick, even heat with a torch around the injector bore, not the whole head, breaks the carbon seal. Done it a dozen times on my old 7.3 without a single crack. Letting penetrant soak for days isn't an option when the truck needs to run tomorrow. The impact gun method just shocks the threads, it doesn't touch the carbon holding the body in.

terryh201mo ago

My old 6.0 cracked from torch heat, so I'm with you on the soak and vibe method.