Spent a whole year torquing injector lines wrong on our Detroit 60s

Always did the final torque on the line nuts with the engine hot, figured it was the right way to account for expansion. Had a weird leak on a Series 60 last week that wouldn't go away. The old head tech from the Freightliner dealer in Boise was in and just asked, 'You doing those cold or hot?' Turns out the manual specifically says final torque at ambient temp. I must have missed that page. How many other little things like that are we all just doing wrong?

3 comments

3 Comments

ward.tara1mo ago

Oh man, that's a classic. The hot torque thing makes so much sense in your head, right? I've seen guys do the same on aftercooler housings, thinking they need to be snugged up hot. The manuals are so picky about ambient spec for a reason, it's all about the clamp load settling right as things cool down.

avery_allen1mo ago

Yeah it's such an easy trap to fall into lol. I watched a guy fight a turbo exhaust flange for an hour because he kept trying to torque it while the engine was hot. The bolts just kept stretching and it never sealed right until he let it cool.

janag431mo ago

Honestly, feel your pain on that one. Tbh we've all been burned by a tiny detail in the manual.