The debate on using thread locker on injector hold-down bolts...

Last week at the shop in Spokane, I had a guy swear red Loctite was the only way to keep injectors from backing out, but my lead tech from 3 years ago told me never use anything but dry torque. I just had a 6.7 Powerstroke come in where the red stuff made the bolts a nightmare to break loose after winter. So, is thread locker worth the risk on injector bolts or should we stick to clean dry threads for the torque spec?

2 comments

2 Comments

paige4271mo ago

You're making a solid point, and I've been down that same road more times than I can count. Take it with a grain of salt, but in my own shop, I've seen red Loctite cause way more problems than it solves on injector hold-down bolts. A couple winters ago, a Dodge Cummins came through here with bolts that were practically welded in place from the stuff, and I had to heat them up just to get them out without snapping. My rule of thumb is clean, dry threads and a good torque wrench every time, because the bolt stretch and clamping force do the real work if your torque values are right. Blue thread locker can be a middle ground if you're worried about vibration, but that red stuff is a headache waiting to happen on any smaller bolt you might need to remove later.

felix8241mo ago

Man I feel you on that. I had a Ford 6.0 come through a few years back and someone had gone nuts with red Loctite on the injector bolts and it was a total nightmare. Had to use a torch and a lot of patience just to get them to budge without twisting them off. Your point about clean dry threads and a good torque wrench is exactly what I've landed on too after learning the hard way. It's one of those things where the simpler approach just works better in the long run and saves you a ton of grief later.