Will acid harm any part of my truck such as hydralic hoses, tires, glass, wiring, plastic lights, or anything else? Should i be careful to only spray metal surfaces?

Yes, you should be very cautious about where you spray it. Make sure that you only spray it on someones pump that you hate. It is such a bad idea, for too many reasons to even get into........  {;~(

That answers my Q. Thanks guys!

Not really,think about it.Depends on where and how much.What is acid going to do with hydrualic cylinder Chrome?.Rubber and wear parts?.Trust me,nothing can beat proper pump hygine.There is nothing that can beat a scraper and hard work.Yes I have used,but gently to brighten paint.Just think about your eyes,should you get lax.I know it was a special at the hardware store for .99.Acid is not the only answer.

I almost forgot,with my failing brain.I remember a operator (not by name) that thought he could get the grout out of his waterbox by leaving acid in it over the weekend.Any guesss as to the outcome?