BX25d proper coolant level and leak?

Mike1964

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Kubota BX25d
Dec 10, 2023
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I'm brand new to this forum, having just purchased a used 2016 BX 25d with 700 hours on it. The dealer told me the machine was fully serviced and ready to go, and in the first few hours I've used it, it has run without incident.

I checked the fluid levels throughout yesterday, and I noticed that the coolant level in the radiator was low (it was at the top of the core, but not to the top of the fill cap). Thinking it was low, I added coolant to the radiator directly (my bad) along with the reservoir (between the + and -). Coolant (mostly water) poured out all over my garage floor, and the levels returned back to the top of the core. Is this normal for a BX (i.e., is this a low fill radiator)?

I ran the thing for about 30 minutes, and the engine was slightly hot but the radiator and upper hoses remained cool. Bad thermostat? Caused by low coolant level?

I'd bring it back to the dealer, but they are a five-hours from me. Any help is appreciated.
 

85Hokie

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When you say you ran it for 30 minutes - did you RUN it or idle it? Did you work it hard? Diesels are funny critters - let them idle around and nothing will get hot. Run them as they should be and the fluids will get to temps.

Go back and run it - IF you have the MMM hooked up, run it -even if not cutting grass ;) - run it at 3,000 rpms and "cut" wind and see if it get hot.

If MMM not hooked up - move something with FEL and work the hydraulics, you will need to get the machine up to temps to see IF it is working as it should. In your neck of the woods it might take a little longer to get there depending on the temp outside.
 
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Mike1964

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Kubota BX25d
Dec 10, 2023
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Thanks for the replies. I ran the machine for about 25 minutes at 3000 RPM, but didn't actually go to work with it. The upper hose was beginning to warm, so I imagine I haven't really pushed it enough to get the temp on the motor up. It was about 35 degrees out, too, so I'm sure that had an effect on things as well.

Thanks to imnukensc for the links to the manuals. I downloaded the BX25DLB and read through that awhile back, but looking at the BX25, it's a lot more detailed (448 pp. as opposed to 115 for the DLB).

I'm still curious about the overflow in the radiator above the core. I've never had a radiator flood simply by filling it to the cap. That troubles me. Machine does seem to run fine, but I don't want to burn up the engine if there's something easy that I can catch now.
 

cthomas

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LX2610 HSDC
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is the overflow hose hooked up? Does it have a hole in it. It is easier to replace the radiator cap than it is to test it.
 

Russell King

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Where did the water leak out of? I think it should’ve filled the reservoir completely before it started leaking onto the floor.
 

DustyRusty

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2020 BX23S, BX2822 Snowblower, Curtis Deluxe Cab,
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It is a closed system and you are not supposed to open the cap. The cap is designed to purge excess coolant into the reservoir when the engine is hot and suck coolant out of the reservoir when the engine cools, just like on your car, unless your car was built in the 1960s or before. Closed coolant systems have been around since the 1970s.
 
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Mike1964

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Kubota BX25d
Dec 10, 2023
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Hi all,

Thanks all. Clearly, there is a radiator leak somewhere in the system that was not caught by the company that sold me the tractor. I added new fluid to the radiator, and the system ran normally (no tstat issue). When I shut it down and opened the cap to check the fluid level in the radiator, it leaked like a sieve.

Looks like either a radiator or hose issue to me, or possibly a clamp. Doesn't look like it's coming from the block, but it's difficult to see much of anything.

I reached back to the company that sold me the unit ("fully serviced" before purchase), so we'll see where it goes from here. Disappointed in this, to say the least, but, again, thanks to everyone for your responses.
 

85Hokie

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" opened the cap to check the fluid level in the radiator, it leaked like a sieve. "

where did it leak FROM? From the the top of the radiator, at the neck?
 

cthomas

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Jan 1, 2017
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Did you open it while is was hot/pressurized? If so that is normal. Really need more information other than it leaked on the garage floor.......
 

DustyRusty

Well-known member

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2020 BX23S, BX2822 Snowblower, Curtis Deluxe Cab,
Nov 8, 2015
6,237
4,816
113
North East CT
Hi all,

Thanks all. Clearly, there is a radiator leak somewhere in the system that was not caught by the company that sold me the tractor. I added new fluid to the radiator, and the system ran normally (no tstat issue). When I shut it down and opened the cap to check the fluid level in the radiator, it leaked like a sieve.

Looks like either a radiator or hose issue to me, or possibly a clamp. Doesn't look like it's coming from the block, but it's difficult to see much of anything.

I reached back to the company that sold me the unit ("fully serviced" before purchase), so we'll see where it goes from here. Disappointed in this, to say the least, but, again, thanks to everyone for your responses.
Did you read my response to your original question above? I clearly explained why you don't open the cap under any condition. You check the coolant level by checking the overflow tank.
 

jaxs

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B1750HST
Jun 22, 2023
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522
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Texas
I second the motion on not loosening nor removing radiator cap any time coolant is above ambient temperature. Aside from not being correct way to check coolant level, you risk seriously injuring yourself. Adding cold water to radiator while engine is hot is also bad,it can crack head or block. If you must add water while engine is at operating temperture,only put it in overflow reservoir.