Mice Chewed a Coolant Hose on My Kubota L2501: Replacing the Water Return Hose

Short answer: Mice chewed through the small rubber water return hose on my Kubota L2501, which caused a coolant leak. The radiator hoses were fine. I replaced the water return hose, topped off the coolant and ran the tractor until the thermostat opened, then rechecked the level.

The damage

While nobody was around the shop for a while, mice moved in and chewed on everything. They even ate the handles of screwdrivers lying next to one of my projects. On the tractor, they went after one small hose: the water return hose (Kubota calls the part the water return pipe). It's a short piece of rubber hose, but once it's chewed through, coolant leaks out.

Getting to the hose

1. Pull the small pin and slide the panel back.
2. Release the hook at the bottom right and lift the panel straight up.
3. The water return hose runs up and to the right. It's held by two hose clamps, one at each end.

Replacing it

The plan was to squeeze both clamps with pliers, slide them back and pull the hose off. The old hose wouldn't release, so I cut it off. Once it was off, the damage was obvious: the mice had chewed it apart. The new hose went on much more easily than the old one came off. I slid the clamps back into place over both ends.

Refilling and checking

I filled the coolant reservoir back up. Then I needed the thermostat to open so the coolant would circulate and the level could settle. I drove the tractor out and back until the temperature gauge rose, which showed the thermostat had opened. When I checked the coolant again, it was still full, so it hadn't lost as much as I expected.

Common practice: use the coolant type your owner's manual calls for, check the level only when the engine is cool, and look over the other hoses and wiring while you're in there, since rodents rarely stop at one part.

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