At about 70 hours I noticed the coolant overflow tank level was dropping. I don't run the machine hard, in a little under 2 years I only have 110 hours on it. Took it to the dealer, still under warranty, and they had it for a couple of weeks using it in their yard to find the leak. They did not notice the level dropping until after a couple of hours of use. Once they recognized there was an issue, they could not find any leak. Dye in coolant, new radiator cap, "pressure" test, no sign of leak. I brought it back home and have continue to monitor, between the time they had it and now, 110 hours, the level is still dropping. not to the point where I need to add coolant, but it is still going down. Anyone have any experience like this? One of the service advisors told me that, "sometimes you just have to add coolant once in a while." Any advice would be helpful.
Dropping by how much? How much coolant are you adding and are you going to the full mark on the tank every time..................over how long??
It's real intermittent, from 70 hours to around 85 hours it has dropped about half a tanks worth, from the full mark. I have attached a pic with the marks that I noted. This was over about five months.
It may have such a small leak that a pressure test is unable to pick it up yet. That also depends on how the pressure test was performed. To do it properly, the system would need to be checked while cold, then hot..........while engine is stopped, idling, and running. I even like to do the next step and watch a pressure test with the engine under a load and heated up good. No more than you are using this machine a determination may take a while.
Thanks for that reply, wish I was close to OK to have you take a look at it. LoL The shop is trying, but they don't have the time to devote to it and I'm sure Kubota is not real willing to pay them for all that diagnosis based on how little it is losing. I think the new radiator cap was just a way to get Kubota to pay for the shop labor for what they did so far.