Met a diesel guy at a truck stop in Flagstaff who fixed my injector issue with a rubber mallet

I was stuck on a job near Flagstaff last month, chasing a rough idle on a 7.3L that no scanner could pin down. Guy in the next bay over at the repair spot saw me frustrated and asked if I checked the return line fittings. I said yeah, they looked fine. He just grabbed a rubber mallet, tapped each injector line once, and one of them clicked loose. Apparently the banjo bolt was snug but the washer had a hairline crack that only showed under heat. He said he learned that from a fleet guy in Phoenix who used to do it blind. Saved my whole afternoon. Anyone else got a weird old school trick that beats a diagnostic tool every time?

1 comments

1 Comment

the_emery21d ago

I mean sure, tapping stuff is old school and all, but a cracked washer that only shows under heat is still gonna bite you down the road. The mallet just told you where to look, it didn't fix the problem. I'd rather spend an hour with a good scan tool than trust a lucky hit on a part that's already half dead.