I was flipping through my Honda’s owner’s manual when I came across instructions to properly jump start the battery. The directions say to disconnect a metal strap or two connected to (or touching?) the power steering reservoir. Why would this be?
…Unfortunately, I read this tip too late. 
It’s the grounding strap. Is your Honda an Odyssey?
Unless it burned a hole in it I can’t imagine anything else. So what happened???
Is that what it says, or does it say “Remove the power steering resevoir from the bracket. Pull it away from the grounding strap.”
Because that’s different.
What you said implies they want to electrically isolate the reservoir for some reason. What I’m reading in a manual (what it says above) tells me the connection point they want you to use is under the reservoir and the only way to get at it is to lift it off the bracket, exposing a ground strap (that has nothing to do with the reservoir itself).
I have seen cases where metal woven hydraulic lines comming off of the p/s were the only available grounds and they burned up starting the fluid on fire. But I would think that a ground strap should prevent that.
The metal brake lines touch to the body, and may start to cook if the engines proper ground strap is not working. The engines ground strap can be damaged by the constant vibration it gets… Or it can be damaged by rocks, or corrosion, or being covered in oil/grease, I guess.
In practice, a meteorite might hit you too
Also, all this talk about ground straps may seem irrevevant, if you didn’t also read the note saying
"connect +ve’s of the battery together first,
THEN connect from the -ve of the working car to the chassis or motor of the “flat” battery car, clipping on the black (-ve) wire to the flat car LAST.
When disconnecting, Disconnect that black wire from the flat car FIRST
The reason is to prevent sparking near the battery, because the battery may be producing lots of Hydrogen gas.May. Sometimes. Of course you’ve done this 1000 times with no problem… it might someday, one in a million, explode ?
So thats why the ground strip between chassis and engine gets involved… And the brake lines may be the path the current takes…
When I first opened this post, I thought it was something about the new electric power assist steering on a lot of vehicles. However they don’t have reservoirs so it must be about the old hydraulic pump systems.