Ok...it's a hitachi ex60urg. I accidentally put diesel in the hydraulic tank. It never was started after discovering the mistake. My question is, if I drain and refill the tank, is that enough? There will, no doubt, be a bit of residual. How big of an issue will that be? Do they mix? Thanks.
I assume you mean a tank that already had hydraulic oil in it and you just accidentally added diesel to it, no? If that's the case, and you have not started the machine, then go ahead and drain just the tank and re-fill with new oil, I doubt you'll have any issues. As for mixing, with the cost of parts now days, I wouldn't take the chance.
You are correct... The part I worry about is the small amount in the pickup tube for the pump, which is lower than the drain plug. It might be a half a gallon. The total amount of fuel added was maybe 10 gallons... and it was in there for maybe 3-4 hours. It was just by chance that the operator decided not to run it.
Even though the pipe that feeds the pumps goes directly into the bottom of the tank, the inlet on hydraulic tanks is typically several inches above the bottom of the tank, inside that tank that is. And they typically incorporate a mesh strainer on the inlet inside the tank. As long as there was oil already in the tank, and you haven't started/run the machine, I would have no worries about residual from draining the tank and re-fill with fresh oil.
Ah..ok...i get that. You don't want the pump sucking any sediment that settles in the tank. Thanks!
No problem atk_nut. And next time you drive by an equipment dealer you should wheel in and ask the parts guy for a "Hyd Oil" and "Diesel Fuel" decals to properly identify those two fill ports...just to (hopefully) prevent this from happening again in the future.
Thanks. Good tip!
I have two unsolicited things to say (anyone surprised?): First, since fuel is inherently lighter than hydraulic oil and the oil wasn't circulated, should it not stay more or less on top? Second, in the past it was not unusual for a manufacturer to suggest a mix of 50/50 oil/diesel for flushing a hydraulic system. Newer fuel may not be as compatible with seals and such, but I doubt a mix will do much harm unless you leave it in there.
Back in the '80s, I worked for a company that had 75-80 tractors pulling end dump trailers. We actually had a procedure for what to do if a truck blew a hydraulic hose a long way from home. Swap a hose from a truck that had already dumped, or get a hose made somewhere. If you didn't have enough hydraulic oil to raise the bed all the way up, fill hydraulic tank with diesel from fuel tank. If you only put in a little diesel, run it. If you put in a lot of diesel, finish the day, or the week, when you went to fuel truck at the shop, stick the wetline hose into the 10,000 gallon fuel tank and pump the hydraulic tank until it stopped flowing, refill w/ hydraulic oil, run it. A little diesel in the hydraulic oil, or a little hydraulic oil in the diesel never seemed to hurt their stuff.
That's some interesting info Mitch.
Gear pumps and mechanical engines... I'm all for some latitude in situations like this, but both hydraulics and fuel systems have gotten a lot tighter on tolerances, and the fuel is different chemically than it was then. Caution is the name of the game with newer equipment, YMMV
That's kinda where I'm coming from. If the engine wasn't started we're only talking about the oil in the tank, and on an EX60URG I can't imagine that would be more than 25 to 30 gallons. Besides, wouldn't hurt to put a fresh charge of oil in the tank anyway if the machine has some hours on it.
Oh, I agree, I should have been clearer. My point was that the possibility of a few ounces of residual fuel in a tank of new oil was highly unlikely to be a big deal. When we pumped 10-20 gallons of hydraulic oil into a 10,000 gallon fuel tank it probably wasn't even enough to count as a lubricity improvement
10-4!