Dripping fluid on cold start - RESOLVED w/ info

[Timmer92]

Hi all. I purchased my L3901 new almost a year ago. So this is my second winter with it. I store it an unheated shed. I'm diligent about letting it warm up for 20-30 mins in cold weather. On cold days, I would say maybe under 20 deg (F), I notice what I would describe as more than a few drips but less than a pool on my shed floor after warm up. The liquid is slightly greenish. It seems thicker to me than coolant. From a visual perspective, I cannot figure out where it is coming from. Admittedly, I have always had the need to get working, and then after working I don't want to run my hands in and around things when it's hot, so I haven't figured out the source. I do check my fluid levels to make sure I'm ok to run it. What do I need to worry about or fix?

It's coming off the left side. Picture is attached. You can see the fluid accumulated on the zip tie. Given it's on the outside, and I can't see anything obvious above it, I was thinking maybe it was spraying on the inside of the hood and then dripping, but I didn't see evidence of that.

Thanks for your help!

 

[dirtydeed]

Can't say for sure but I'd look/check the hose clamp and sending unit directly above your circle. You may just need to snug that hose clamp.

 

[SidecarFlip]

Tighten your hose clamps, all of them. Pretty common occurrence in the winter and why hose clamps are spring loaded on big trucks, so the clamp pressure maintains itself.

 

[BruceP]

DEFINANTLY antifreeze.... also check that the sensor just above the drip is not leaking where it screws into the block. You can pull off the wire from the connector and snug it up 1/4 turn or so.

BEWARE: that a known failure-mode for sensors is to leak where they are not supposed to.... so DO NOT over-tighten it while trying to eliminate leak. (breaking off a sensor is not fun to recover from)

also BEWARE: the leak may be elsewhere and is getting INTO the wire-harness and following it (like a hose) several feet before leaking out at this area.

Another approach is to slide clean paper-towel just above that wire-harness the next time you park it. Inspect for green 'spotting' later.

It may be a good idea to WASH the engine down so it is easier to isolate where leaks are coming from. That layer of dust may be hiding something. A bucket with water/dishsoap and a brush should be sufficent to get into nooks/crannies.

 

[Thunder chicken]

I had a similar leak last winter in the cold. The Kubota rad hoses/clamps seem to ‘move’ in the cold, as mentioned above, sort of a normal thing. It’s easier to add a bit of antifreeze. All last winter I lost maybe a 1/4 cup. Looked like a lot some days. I marked the expansion tank and kept an eye on it. So one day I changed the hoses. About $100 later, I’ve saved loosing a 1/4 cup of antifreeze! No leaks this cold winter so far...

The WSM for my machine says to replace the rad hoses and antifreeze every 2 years, fwiw. (This would have been going on 3 years) so I guess they’ve made things to last just the way they say

 

[Lil Foot]

I have often found various antifreeze leaks that looked too thick to be antifreeze. That's because engine heat often boils away the water and lighter elements, leaving only a heavier, oilier looking residue.

 

[North Idaho Wolfman]

Look at the Block heater very closely that's probably where your leak originates from.

 

[whitetiger]

Hi all. I purchased my L3901 new almost a year ago. So this is my second winter with it. I store it an unheated shed. I'm diligent about letting it warm up for 20-30 mins in cold weather. On cold days, I would say maybe under 20 deg (F), I notice what I would describe as more than a few drips but less than a pool on my shed floor after warm up. The liquid is slightly greenish. It seems thicker to me than coolant. From a visual perspective, I cannot figure out where it is coming from. Admittedly, I have always had the need to get working, and then after working I don't want to run my hands in and around things when it's hot, so I haven't figured out the source. I do check my fluid levels to make sure I'm ok to run it. What do I need to worry about or fix?

It's coming off the left side. Picture is attached. You can see the fluid accumulated on the zip tie. Given it's on the outside, and I can't see anything obvious above it, I was thinking maybe it was spraying on the inside of the hood and then dripping, but I didn't see evidence of that.

View attachment 52547

Thanks for your help!

Tighten your hose clamps and check to see that the lower hose is not coming off the nipple. Check around the block heater while you are at it. You do not need to worry about the engine oil pressure sender in the picture as they typically do not leak coolant.

Last week we had the fifth unit that I have seen come in with the lower hose clear off of the nipple, no coolant, and a scored engine. The clamps must be maintained!!!!!

 

[Timmer92]

Thanks guys. I will take a look tomorrow.

 

[Captain13]

One way I have found to track down leaks is to dust the area with baby powder. Then start it up and watch for the liquid trail to see where it originates. I agree that it’s probably your clamps but if you want to track it down, maybe this method will help.

 

[DogHandlerMN]

I’ve had the same problem intermittently, thanks for asking, helped me out too!

 

[Timmer92]

Ok, I have an update. First off, I used the tractor again with the same dripping, so the problem didn't magically go away. I usually solve mechanical problems through luck or turning up the radio and that isn't working for me!

I decided I was going to have to find the darn source. I spent quite a bit of time on it and am even more perplexed than I was when I had only casually looked at it.

I took the side cover off so I could get a clear look. I confirmed that the only place I am finding any residual fluid is in the red circle area. I visually inspected with an LED light, and ran my hand along the various electrical and other hoses above and towards the back of the spot and found no sign of liquid. This includes, I believe, the possibility of it running down the inside of any wire harness. I am fairly confident it's not coming from above or to the rear.

Next I LOOKED at the bolt just above and to the left of the spot. I admittedly didn't see anything so I didn't bother to feel it. Maybe this was shortsighted, so I will recheck. My gut at the moment is this isn't the spot as I think I would have seen some sign. I was kind of saving the horizontal hose coming from the radiator for last as I really expected this to be the culprit and was enjoying familiarizing myself more with the tractor while ruling things out. However, this is where my disappointment started. I gave the hose a strong wiggle and pull, and both ends appear to have a solid connection. I grabbed a screwdriver and found the clamps to be tight. More importantly, the dust was undisturbed around the clamps on both ends, as well as underneath and behind the hose. There was no sign of any liquid in the immediate surrounding area on either end.

So, my abilities seem to be limited to drawing red circles for you smart folks. Embarrassing question - some of you mentioned the block heater, and some of you mentioned the sensor. Is the circled bolt one or both of these? Maybe there is another heater bolt I need to find and check? What else?

Thanks to all!

 

[PoTreeBoy]

Ok, I have an update. First off, I used the tractor again with the same dripping, so the problem didn't magically go away. I usually solve mechanical problems through luck or turning up the radio and that isn't working for me!

I decided I was going to have to find the darn source. I spent quite a bit of time on it and am even more perplexed than I was when I had only casually looked at it.

I took the side cover off so I could get a clear look. I confirmed that the only place I am finding any residual fluid is in the red circle area. I visually inspected with an LED light, and ran my hand along the various electrical and other hoses above and towards the back of the spot and found no sign of liquid. This includes, I believe, the possibility of it running down the inside of any wire harness. I am fairly confident it's not coming from above or to the rear.

View attachment 52774


Next I LOOKED at the bolt right above the spot. I admittedly didn't see anything so I didn't bother to feel it. Maybe this was shortsighted, so I will recheck. My gut at the moment is this isn't the spot as I think I would have seen some sign. I was kind of saving the horizontal hose coming from the radiator for last as I really expected this to be the culprit and was enjoying familiarizing myself more with the tractor while ruling things out. However, this is where my disappointment started. I gave the hose a strong wiggle and pull, and both ends appear to have a solid connection. I grabbed a screwdriver and found the clamps to be tight. More importantly, the dust was undisturbed around the clamps on both ends, as well as underneath and behind the hose. There was no sign of any liquid in the immediate surrounding area on either end.

View attachment 52778

So, my abilities seem to be limited to drawing red circles for you smart folks. Embarrassing question - some of you mentioned the block heater, and some of you mentioned the sensor. Is the circled bolt one or both of these? Maybe there is another heater bolt I need to find and check? What else?

Thanks to all!

If it's leaking green, it's coolant. That device you have circled is the oil pressure switch (not temp. sensor). The brass colored thing with the orange connector in the other picture is a block heater, I think.

You could borrow/rent a cooling system pressure tester from your parts store, clean up that area, pressure it up, and see where it leaks.

 

[BruceP]

You have circled the sensor I mentioned previously (the one with the wire attached and some blue paint) it SURE looks to me as if that may be the source of the leak.

Have you tried wrapping a sheet of paper towel around that sensor... then after working the tractor, check it for green stains.

My gut tells me there is a leak between the metal/plastic of that sensor. (again, this is a COMMON failure-mode for these sensors) I would verify it is screwed in snug first.

 

[Timmer92]

You have circled the sensor I mentioned previously (the one with the wire attached and some blue paint) it SURE looks to me as if that may be the source of the leak.

Have you tried wrapping a sheet of paper towel around that sensor... then after working the tractor, check it for green stains.

My gut tells me there is a leak between the metal/plastic of that sensor. (again, this is a COMMON failure-mode for these sensors) I would verify it is screwed in snug first.

This sounds more likely than anything else at this point. Maybe it's sneaking out between components and dripping straight off, thus not providing any visual proof. I will put some form of a towel around it, maybe zip tie it, and confirm if this is the source. Thanks!

 

[Russell King]

If you can’t locate the leak you can get a ultraviolet die to put into the radiator. Then a black light and special glasses will narrow it down quickly.

These are available online or at the local auto parts store.

Just be sure to get the correct kit since there are different kits for different fluids (oil for example)

 

[lugbolt]

I have seen hundreds of 3301/3901/4701's leaking coolant

99% of the time tightening the clamp(s) fixes the leak(s)

they use cheap worm drive clamps that don't hold constant tension on the hose and connection.

when u "check" them, use a socket. A screwdriver won't get them tight enough.

 

[whitetiger]

You have circled the sensor I mentioned previously (the one with the wire attached and some blue paint) it SURE looks to me as if that may be the source of the leak.

Have you tried wrapping a sheet of paper towel around that sensor... then after working the tractor, check it for green stains.

My gut tells me there is a leak between the metal/plastic of that sensor. (again, this is a COMMON failure-mode for these sensors) I would verify it is screwed in snug first.

This sounds more likely than anything else at this point. Maybe it's sneaking out between components and dripping straight off, thus not providing any visual proof. I will put some form of a towel around it, maybe zip tie it, and confirm if this is the source. Thanks!

Once again, the switch you have circled is an ENGINE OIL PRESSURE SWITCH. See pdf

 

[je1279]

I have seen hundreds of 3301/3901/4701's leaking coolant

99% of the time tightening the clamp(s) fixes the leak(s)

they use cheap worm drive clamps that don't hold constant tension on the hose and connection.

when u "check" them, use a socket. A screwdriver won't get them tight enough.

Another option I've used in the automotive world for hose clamps that love to loosen are t-bolt clamps. Just make sure that you have the room and do not overtighten them as they will crush whatever is underneath the hose.

 

[BruceP]

Once again, the switch you have circled is an ENGINE OIL PRESSURE SWITCH. See pdf

Thanks for that... I know that is a sensor, but not sure what it is sensing. Assuming that the leakage is indeed antifreeze, we can rule-out the oil-pressure-sensor as the issue.

It would not hurt to follow-through with wrapping it with a sheet of paper towel to eliminate it as source of leakage.