Best stuff I ever used was the purple liquid the Navy Non Destruct Test (NDT) guys used looking from cracks. Stuff was so thin it would soak through your skin! Had a small bottle that lasted me twenty plus years. Probably still used but not for us civilians. Sorry,, don't know what it was called.
The best way to get the real CCC is to load up with fluids and people then drive to a CAT scale. CAT scales certify their accuracy.
Then once loaded go get a 4-wheel weigh so you know which parts of your load need to shift from one corner to another.
You rig will drive so nicely once you adjust everything.
I had spares of just about anything a person would need when I had the Freightliner, I am building my spare parts package for the Pete, today when I bought the filters I also got an air governor and a full set of spare belts. I am getting there with this truck, when I sold the Freightliner, Gene and Kat, were pleasantly surprised by all the spare parts that came with the truck to include both cam and crank sensors, which will be added to the Pete's spare parts kit.
Having the 18 speed makes mountain driving a real treat, being able to split gears makes it easy to maintain speed with out having to rev the heck out of the engine, I really do love this truck.