Kubota B7100HST-D adding lower radiator hose engine heater **UPDATE

[TerryKing]

Hi Everyone,

OK after some research and forum searching I have installed a coolant heater in the lower radiator hose of my B7100HST. This is a 600 watt heater with 1.25 inch diameter hose connections. (There are many such heaters that are 1.5 inch diameter and many of the newer Kubota apparently use those. )

Here's what it looks like. Note: Later I rotated it to position the electrical connector ABOVE it.:

After draining the coolant from the front-of-radiator drain valve, I carefully pried with screwdrivers and hand rotated and finally got the OLD hoses off.. I was worried about stress on the radiator connections.. The lower hose connections are a little unusual. The Radiator connection has quite an offset to clear the engine:

The other end is on this 'pipe' which appears to be screwed into the block:

Here's the lower hose, from Messicks:

The heater itself looks like this: (This from O'reilly's, but most auto parts places have these..) Amazon has it here for twice as much .

After holding the parts up to see what would fit, I marked and cut the hose. I took out a 1.25 inch section which is the heater width.

Later I thought 4.0 inches would be better.. Here it is with the electrical connection rotated below. (CHANGED later to UP)

Hose clamps tight and time to refill:

I put in 4.5 Qt and it was ALMOST full:

Another 3 or 4 Oz and it was overflowing. Here's the (NEW UPDATED) view:

I ran the engine for 30 mins to check for leaks. A little coolant came out the overflow as expected.. Left it all day until engine head and radiator were down to 48F. (Infrared scan thermometer). Plugged in the heater and its metal case quickly got hot to the touch. I was a little concerned when it got up to 180F pretty soon. But then it stabilized there or lower. It is supposed to have thermostatic control. It took a Long time to start heating the radiator and engine by convection. But after an hour it took the engine head from 48F to 85F. Radiator top was same.

I will update in a couple days with test from a below-freezing morning.. I am also adding a battery warmer and maybe other stuff; I'll update here and also update some January ZeroF - experience.

Thanks for many helping posts I have read...

 

[85Hokie]

Excellent write up....

Typically after an hour in cold - you reach a point of no return.

I understand that some of these do not last long - I would imagine that is directly proportional to time used too.

 

[North Idaho Wolfman]

Couple things to note:
The electrical connection should be to the side or the top.
Do not leave it plugged in for more than an hour if you want it to last.
My B7100 starts in the dead of winter outside -20f without a heater.

 

[TerryKing]

My B7100 starts in the dead of winter outside -20f without a heater.

..And a REALLY good battery GLAD to hear THAT!

A good battery maintainer that keeps it at 13.6V all night (I like THIS one) makes the biggest difference. I have those on 2 cars and 2 trucks and they start in the RealCold in Vermont. Maybe even in Idaho..

 

[TerryKing]

connection should be to the side or the top.

Yes, usually agree. I don't think the side panel will go on with it to the side, and I think the top position would hit the upper block. I'll get a better look with the side panel back on.. Can probably rotate it with clamps backed off and no pressure in system.. without loosing coolant. Need to route and secure the AC wiring. Probably will have battery maintainer and battery warmer all on same external short AC dongle.

***UPDATE*** Wolf, NotToMySurprise you were Right. I loosened the clamps a bit and rotated it so electrical connection is UP. It just fit under the air cleaner bracket after all. Thanks!

 

[North Idaho Wolfman]

..And a REALLY good battery GLAD to hear THAT!

A good battery maintainer that keeps it at 13.6V all night (I like THIS one) makes the biggest difference. I have those on 2 cars and 2 trucks and they start in the RealCold in Vermont. Maybe even in Idaho..

Yes the B's are pretty tight under the hood!
I prefer the block heaters over the Hose heaters.

This will really have you scratching your head, I don't even a battery maintainer on my B.
And yes we get a lot of snow and it is normally COLD all winter long.
Normal winter, it does not warm up above freezing very often.
When the first good snow flies, it will be here till spring melts it.

I will fully agree that heaters (all of my diesels have block heaters) and Battery maintainers, are all good devices to have and use.

I just haven't had to use any of those on my B.
I should note that the B has a fully rebuilt all OEM parts D850 in it, that run perfectly.

I even rarely have to use the block heater on the L.
Now the 743 Bobcat (Kubota V2203) needs a battery maintainer, but that's because I put an unswitched USB charger / supply in it for my phone.

 

[Runs With Scissors]

Nice write up.

I have a factory heater that I try to plug in about an hour before I want to use it, as well a battery maintainer.

Last winter was a little disappointing around here, but generally my area gets below freezing for most of the winter.

The good part about that style heater is that if it goes bad, it looks easy enough to replace.

 

[Thunder Fish]

Great write up,I have been running one for coming up to 3 seasons now,mine is 1000 watt that is plugged into a WiFi plug I turn on about 2 hours prior to using.

 

[TerryKing]

Great write up,I have been running one for coming up to 3 seasons now,mine is 1000 watt that is plugged into a WiFi plug I turn on about 2 hours prior to using.

I WILL do THAT!

 

[number two]

Great write up,I have been running one for coming up to 3 seasons now,mine is 1000 watt that is plugged into a WiFi plug I turn on about 2 hours prior to using.

Wow,1000 watts!
The Kubota block heaters seem to be 400 watts.
An hour works good enough.
May we have a nastier winter now?
Good Luck!

 

[trevoroni]

I haven't had a chance to use my coolant heater but I agree that those WiFi plugs are excellent for block heaters.
I've got a 2 outlet outdoor TP link one that I use for mine and my wife's car.
I can set schedules so that they come on a few hours before we're going to leave in the morning or throughout the day as needed.
Saves on the power bill vs plugged in all day during the cold spells.

 

[fried1765]

Great write up,I have been running one for coming up to 3 seasons now,mine is 1000 watt that is plugged into a WiFi plug I turn on about 2 hours prior to using.

THAT is the most effective/efficient way to use these devices!

 

[Donystoy]

Just curious! Is there a thermostat bypass on these tractors? Otherwise, how does the water circulate through the engine if the thermostat is closed as it is when cold. Can't remember what the thermostat looks like. Does the heater generate enough heat that it opens the thermostat?
For the first 30 years that I owned my B7200 (before I built my heated shop), I did nothing except for an occasional battery tender hook up. Always started without any issues. Having said that I am sure that it would be easier on the engine if it was pre-warmed up a bit.

 

[Henro]

Just curious! Is there a thermostat bypass on these tractors? Otherwise, how does the water circulate through the engine if the thermostat is closed as it is when cold. Can't remember what the thermostat looks like. Does the heater generate enough heat that it opens the thermostat?
For the first 30 years that I owned my B7200 (before I built my heated shop), I did nothing except for an occasional battery tender hook up. Always started without any issues. Having said that I am sure that it would be easier on the engine if it was pre-warmed up a bit.

My guess is that circulation of the water within the block is due to natural convection.

You actually wouldn’t want the thermostat to open and allow circulation of the water in the block through the radiator, as that would just send energy out into the environment and cool the block, which would work against the block heater.

 

[trevoroni]

It doesn't have a thermostat or even a water pump.
It functions via a thermosiphon system that circulates with the natural heating and cooling of the fluid.

 

[Henro]

It doesn't have a thermostat or even a water pump.
It functions via a thermosiphon system that circulates with the natural heating and cooling of the fluid.

Well, I guess that answers the question. with respect to Terry’’s tractor.

But in general newer tractors do have thermostats in the cooling system flow path…or so it seems...

 

[TerryKing]

answers the question. with respect to Terry’’s tractor.

Yes, and my experience is that the top of the radiator gets to about same temp as the engine head. Colder coolant at the radiator bottom goes back thru the heater and into the block.

I think a system with a thermostat in the engine outlet would hold heat in the block better..

The larger tractors with block heaters and a thermostat would keep heat in the engine and get it hotter for same heater power. Anyone confirm that?

 

[Henro]

Yes, and my experience is that the top of the radiator gets to about same temp as the engine head. Colder coolant at the radiator bottom goes back thru the heater and into the block.

I think a system with a thermostat in the engine outlet would hold heat in the block better..

The larger tractors with block heaters and a thermostat would keep heat in the engine and get it hotter for same heater power. Anyone confirm that?

I doubt anyone can confirm that, but who knows?

My BX2200 has a thermostat I believe, and is not a large tractor.

At the end of the day, I think common sense may rule in this case...but again, who knows?

So I think the practice should be: When in doubt, heat it up!