I bought a 1994 580sk. When I pop the hood, on the left, facing forward, is the diesel cap. On the right is the hydraulic fluid cap. But I have a tank in the middle, that looks to be plumbed into the diesel tank. Is this an auxiliary fuel tank? I can't find anything on the webs about it, and it's not in the operation manual, or the maintenance chart on the hood. I'll post a pic when I figure that out...
You are correct about it being an auxiliary fuel tank. It has an additional hose on the bottom of it also.
Cool, I like it when things turn out to be simple! Thanks, Tinkerer.
The plastic tank was affectionately called a buddy tank, but in the manuals it was listed as an “optional tank” in the fuel capacities specifications. It was installed to provide the SK with enough fuel to run a full workday of production digging without refueling, which is probably overkill as many jobs don’t utilize a backhoe for constant digging. As Tinkerer noted, it is plumbed in parallel with the main fuel tank. If you completely fill your main tank, you will see the fuel rise in the buddy tank. I usually remove the buddy tank cap when filling my SK as it will then give you a visual indication of when to slow down the flow on the fuel pump nozzle filling the main tank to avoid backsplash/overflow.
Oh. Handy to know! I usually just add a few 5 gallon cans, when it has been a while since I have added fuel. The guages haven't worked since before I bought it. BTW, does anyone know what fittings the hydraulic test ports are set up for? I'm trying to tool up for future troubleshooting, and that seems like a good place to start. I picked up a variety of JIC fittings, plugs, some guages, and a few spare hoses. All from surplus supply, online. Relatively cheap and fast. But I have to break into a circuit, (and spill hydraulic fluid) to measure hydraulic pressure, because I don't have a clue about these test ports.
Google Parker PD test port fittings. Most common size adaptor to use is 1/4"