I worked for farmer O/O's who for the most part, did their own repairs and maintenance. As a company driver, it was expected of me too. It's just the way they do things. I kept a tool kit, jumper cables and my WD-40 and duct tape with me, and I did my own trailer greasing and brake adjustments.
There were a few times on the road I needed to figure things out for myself. One time it was my own fault, as I ran out of fuel about 5 miles from the truck stop I was trying to make it to.
I had to drain some fuel from my reefer tank to save myself from a big roadside rescue bill. No way my boss was going to pay for this screw up, and I wasn't sure I wanted to tell him, but I did and he laughed, and said he ran out of fuel once in Chicago.