TIL why my old mentor hated impact wrenches on injector cups

Back in 2018 at Pete's Diesel in Omaha, I used to zip out injector cups with my 1/2 inch impact every time... thought I was saving time. Took me 3 years and a cracked cylinder head on an old Cummins ISX to realize how much harmonic stress I was putting on the block. Now I only use a breaker bar and torque wrench, even if it takes twice as long. Anyone else have a tool habit you had to unlearn the hard way?

2 comments

2 Comments

wesley87329d ago

Used to be exactly the other way with me. Thought impacts saved time and figured the old timers were just set in their ways. Then a coworker of mine had a similar issue to what @xena_williams mentioned with a Freightliner, hairline crack showed up after a long haul. Changed my mind real quick when I saw the repair bill and the downtime. Now it's strictly hand tools for anything that touches the head.

xena_williams29d ago

Oh man, I feel this one hard. I had a buddy who swore by impacts on injector cups and laughed at me for being slow with a breaker bar, then he ended up with a cracked head on a Freightliner and had to eat crow and a 4k repair bill. I read somewhere that those impacts send shockwaves through the cast iron that can cause stress fractures over time, especially on older blocks that are already a little tired. It's wild how something that feels like a shortcut can actually cost you more in the long run, you know? Now I'm the same way, I'll take the extra 15 minutes with a torque wrench over gambling with a $3,000 head any day.