External Oil Cooler for BX?

[RickB]

Rick b, if you did a search on bxs, you would see that bx can show higher then normal heat d during summer under heavy load sure to sensor is mounted right next to muffler

So a Kubota BX series tractor has a hydraulic oil temperature gauge?

 

[MoreCowbell]

So a Kubota BX series tractor has a hydraulic oil temperature gauge?

The BX line only has an engine temp gauge, which is why I share the concern of the folks here that high trams fluid heat is bad, but there is no way to gauge the actual temp. I'm not inclined to assume that the Kubota engineers got it right (i.e. trams fan issue).

What I'd like to do is install a trams oil temp gauge on my BX and go from there.

Here is a question for the experts: the manual says to let the HST warm up before usage. Do HSTs run the risk of damage do to oil that is too cool?

 

[David_Kb7uns]

The early BXs had three lines going from left side under the tractor and up to valve on right side, the newer ones have the valve under the battery and steering wheel. Intercept the tank return line and run a few loops up and between the radiator and the bulkhead and it shoul be more than ok and get the coolest air as it flows from the rear to the front.

David Kb7uns

 

[uglyboywith11fingers]

The early BXs had three lines going from left side under the tractor and up to valve on right side, the newer ones have the valve under the battery and steering wheel. Intercept the tank return line and run a few loops up and between the radiator and the bulkhead and it shoul be more than ok and get the coolest air as it flows from the rear to the front.

David Kb7uns

This sounds almost do-able... many cars/SUVs use a simple loop or two in front of the rad for PS or trans cooling, so there must be a reasonable degree of fluid cooling. if I understand correctly, this return line should be low pressure... ?

Pete

 

[radioman]

Not hydrualic temp-- engine temp is what I meant. Thing is that the BX is nearly run completely on hydro oil except for engine. What I was getting at, is that when pto is bing used, or the tractor is pulling hard, the engine works harder thru the pto shaft, engine temps rises. Its kinda like these things are hand in hand.

 

[willi67]

The early BXs had three lines going from left side under the tractor and up to valve on right side, the newer ones have the valve under the battery and steering wheel. Intercept the tank return line and run a few loops up and between the radiator and the bulkhead and it shoul be more than ok and get the coolest air as it flows from the rear to the front.

David Kb7uns

I have seen heat sink oil coolers on the net, namely "Derale" brand heat sink coolers, they dont take up much space ... have not seen them on any machine though, anyone know about them?

 

[RickB]

Not hydrualic temp-- engine temp is what I meant. Thing is that the BX is nearly run completely on hydro oil except for engine. What I was getting at, is that when pto is bing used, or the tractor is pulling hard, the engine works harder thru the pto shaft, engine temps rises. Its kinda like these things are hand in hand.

I didn't figure the BX had a hydro oil temp gauge. I strongly suggest anyone contemplating an add-on hydro cooler to incluce such a temp gauge prior to buying a cooler. No gauge means the entire exercise is based on guesswork and TBN theorists' opinions. pickup trucks with towing packages often include trans temp gauges in instances where the base models do not; same deal here.

 

[oakdalecarl]

Gentlemen, when I first saw the mickey-mouse plastic fan for the hydrostatic unit on my new BX1860 I could not believe it. As I was going to use a Bush Hog clearing brush I was more than a little concerned. Well I am almost done with one lot so far two tie rod end boots shredded and one fan scratched (not broken thank God). An add on cooler would be a really good idea.

To get a baseline of fluid temperature why not use a digital grill thermometer with remote readout. It could be attached to a hydraulic line using some thermal conductive paste, a little tin foil and some tie wraps. While not as accurate a readout of actual temperature it would be close and could be moved from place to place. Double tape the readout to a fender and you have an on the go monitor.

Great site by the way, answered a lot of questions already (this is my first real tractor after my 38+ year old Gravely bit the dust).

 

[EE_Bota]

The BX line only has an engine temp gauge, which is why I share the concern of the folks here that high trams fluid heat is bad, but there is no way to gauge the actual temp. I'm not inclined to assume that the Kubota engineers got it right (i.e. trams fan issue).

What I'd like to do is install a trams oil temp gauge on my BX and go from there.

Here is a question for the experts: the manual says to let the HST warm up before usage. Do HSTs run the risk of damage do to oil that is too cool?

I am not an expert, but:

Multi-grade oil helps a lot, but even so, inlet filter screens and anything that is orifice based and relies on pilot flow may behave erratically for cold oil temperatures. I don't think there are many orifices or piloted devices in a BX.

The predominant issue I see with units getting too hot are rubber based issues...such as pump seals and motor seals, and o-rings an the like. At some point lubricity may be threatened, but that will depend on the oil used. I have not seen any reports of 0-ring and seal failure in the Kubota Hydrostatic trannies. If I saw a slew of those, and it was related by the operator to the unit getting hot, I would act.

So if comes down to best first money to me. I am far more worried about lost oil pressure to the engine, engine overheating noticed late, loss or low hydrostat make-up oil pressure, water in the hydrostatic transmission due to heat/cool cycles each day and from use. So, alarms, automatic shutdown, and desiccating filter-breather with color indication of depletion may be better "first money" than an external oil cooler, particularly one without thermostatic control. That's just my opinion, and I am happy for people to spend their own money as they wish.

 

[megaboz]

There are definitely some different thoughts on this topic, and there are definitely some things to consider.

• If under normal conditions and fluids are too hot, you have some other issue and a cooler is only a band-aid.
• Some people like to do these kind of projects and will do them anyway.
• Cooler fluids, in the long run are happier fluids and love to do their job even better when they are happy (I know not scientific, just trying to add a little humor).
• Also, taking fluid samples at certain intervals and having them analyzed is also not a bad idea. The intervals will just depend on how bad/hot you think the fluid is. A $10 test is worth the money, definitely cheaper than swapping fluids or adding a cooler. At least then you would know if you had issues.
• A good oil/hydraulic oil in the first place will do a lot to help with heat issues, not all oils are created equal and will not work equally well for everyone.
• That little plastic fan that everyone loves is a pain to replace and not too cheap, adding a cooler and separate fan (if needed) could be a better alternative then replacing.

But if anyone does decide to do it, post some pics, I would like to see it myself. Might just be the next little project I do to my JD.

 

[oldnslo]

Here is a question for the experts: the manual says to let the HST warm up before usage. Do HSTs run the risk of damage do to oil that is too cool?

If the oil is cold enough it will cavitate the charge pump which then cavitates the HST and all of this is very bad. 40 degrees F no problem. 0 degrees may be a problem. -30 degrees is a problem.

So long and short answer is both extremes in temperature are detrimental to the life of a HST or hydraulic system in general.

Air to oil heat exchangers are very inefficent since oil does NOT release heat to air easily. this is the reason tranny coolers on cars and trucks quite frequently use the antifreeze to cool the oil and then the air to cool the water.

If you interested do a google search for thermal transfer and look at the size of an air to oil cooler to remove 2-3 HP

 

[megaboz]

If the oil is cold enough it will cavitate the charge pump which then cavitates the HST and all of this is very bad. 40 degrees F no problem. 0 degrees may be a problem. -30 degrees is a problem.

So long and short answer is both extremes in temperature are detrimental to the life of a HST or hydraulic system in general.

Air to oil heat exchangers are very inefficent since oil does NOT release heat to air easily. this is the reason tranny coolers on cars and trucks quite frequently use the antifreeze to cool the oil and then the air to cool the water.

If you interested do a google search for thermal transfer and look at the size of an air to oil cooler to remove 2-3 HP

Really? I thought the reason was because car manufacturers were cheap. My truck came equipped with air coolers for the tranny.

 

[EE_Bota]

Really? I thought the reason was because car manufacturers were cheap. My truck came equipped with air coolers for the tranny.

I've heard of some nightmares with the embedded oil coolers, so I think the air coolers would offer me more piece of mind, so you are lucky.

On the Kubota front, the entire transmission housing is a oil to air exchanger, so I think it is pretty important to keep the transmission housing pretty clean. I don't let any gunk build up on the housing, and periodically, I direct jets of air in the area of the fan particularly to make sure grime is not insulating the housing from the air.

 

[kuboman]

Air to ??? heat exchangers are actually quite efficient. Oil is not as efficient at heat absorption/rejection as water/antifreeze but still quite good. I think the reason auto manufactures don't use them more has something to do with the profit margin.
Also using the radiator for the cooler also has the benefit of warming the oil in cold temperatures.

 

[Loudo]

Hello all from Oz, Thank you all for the info and suggestions and help:thumbsup::thumbsup: I should have said the cooler was for the tranny. In reply, I use my BX most days except when we go fishing:laughing: The temperature here is on average 73 to 85'F.After seeing the suggestion on another thread I thought it may be an alternative to replacing that stupid plastic fan as I have done this three times now.On our 40 acre bush block there are a lot of eucalypt trees that drop a lot of smaller sticks and in long grass they are hard to see and they get into the fan blades and they shear off, the neighbour also gets me to do his, I use a flail mower as the MMM is a PITA to attach and remove for me as I have limited movement in my back after arguing with a big tractor,it won, I have put a guard plate on to protect the fuel filters and pump as well as the fan,these have been damaged as well in the past. When this first happened I did not know until I checked that afternoon, almost very costly (see pix) I changed the tranny oil and purchased 2 new fans,one as a spare , I use Kubota UDT oil. As for mounting a cooler I was thinking of putting it in front of the radiator instead of on the side of the ROPS as done in another thread,had a look at it,nice job:thumbsup: very neat. She Who MUST be obeyed says I need a project to keep me out of the house and off the ##@%**! computer:laughing: Well it's a nice day so I am going to hook up my boat and go fishing,any jobs can wait until later Again thank you all for your information and wow what an awesome web site,there is just so much info and knowledge here. Hooroo fromB.R. Bear country

 

[uglyboywith11fingers]

Air to oil heat exchangers are very inefficent since oil does NOT release heat to air easily. this is the reason tranny coolers on cars and trucks quite frequently use the antifreeze to cool the oil and then the air to cool the water.

If you interested do a google search for thermal transfer and look at the size of an air to oil cooler to remove 2-3 HP

I'm not a fancy engineer, so maybe that's why I don't understand...
If the hydraulic oil is on the inside of the tubing, how does it know what's on the outside of the tubing... air or antifreeze ??? Either way, the heat transfer is from the oil to the metal tubing. The next step is then heat transfer from the metal tubing to air, or to the coolant... and one may be more efficient than the other. Ultimately, you've got to dissipate the heat to air...

Pete

 

[oldnslo]

I'm not a fancy engineer, so maybe that's why I don't understand...
If the hydraulic oil is on the inside of the tubing, how does it know what's on the outside of the tubing... air or antifreeze ??? Either way, the heat transfer is from the oil to the metal tubing. The next step is then heat transfer from the metal tubing to air, or to the coolant... and one may be more efficient than the other. Ultimately, you've got to dissipate the heat to air...

Pete

Pete,
I am not an engineer either. All I know is that typically air to oil heat exchangers are significantly larger than oil to water for removing the same amount of heat. They also require lots of air flow.

Roy

 

[boggen]

trying to figure out why need for an oil cooler. for hydraulics. if you are operating in dead zone of any wind, and 110 degree day and no shade. and running things hard and full throttle. everything is going to have some heat issues. cars, trucks, tractors. *been there done that*

keep proper antrifreeze / water ratio in radiator. do your maintance / checks on filters and screens for everything. check your oil levels, and change things as noted in the manual.

do not try to run in to high of gear to get that extra little speed. when under full heavy load. back it down a gear. or let up off the gas pedal some. vs pushing it through the floor board.

there are different oil types out there, and some are pretty crappy and do not hold there worth. contact some local dealers / repair shops for tractors. and ask what they prefer to use. OEM oil vs another brand of oil there can be a large difference. in how well it may hold up for your tractor and rated tempatures your tractor may see.

lines with fins coming off of them. can be good heat sinks. to let the heat coming from the pipe transfer to the fins and dissipate heat. through the air.

oil coolers to radiators, to heat sinks to other. there are 100's of ways to go about it. each way has con's and pro's and amount of heat it can dissipate.