Tried ultrasonic cleaning on a set of injectors and one came out seized solid

Last month I had a set of Bosch injectors from a 6.7 Powerstroke that were all gummed up with carbon and old fuel deposits. Figured I'd throw them in my new ultrasonic cleaner with some heavy duty diesel cleaner for 30 minutes at 140 degrees. Five of them came out looking brand new and sprayed clean. But the sixth one had something weird happen. The ultrasonic vibrations must have loosened up some grit deep inside the nozzle and it wedged the needle valve shut. I couldn't even get it to budge with a brass punch. Now I'm wondering if I should have pulled the nozzles apart before cleaning them or if the cleaner was just too strong for that one injector. Has anyone else wrecked a part with an ultrasonic bath?

2 comments

2 Comments

the_elizabeth2d ago

That grit wedging the needle shut makes me think you should have pulled the nozzles first.

zaranelson2d ago

The grit you're talking about could actually be from a bad batch of resin, not just a dirty job. I've seen it where the pigment clumps up and feels like sand when it cures, especially with those cheaper fast-set epoxies. If they didn't filter the resin before mixing, those little lumps can get in the needle and jam it just like grit would. Pulling the nozzles helps, but if the resin itself is the problem, you'll just clog the new ones right away too. Maybe they should have strained the mix through a paint filter first.