Heater Hoses in tractor Cab ?????

[RickB]

Can Not do it with just a Single shut off... It is in the bypass circuit of the water pump, you would need to complete the path for summer use...
And Yes I have been doing that on my 4 cylinder kubota diesel powered ZTR for years, takes only a couple of min, not a big problem simple and almost Instant heat... KennyV

I don't use the bypass hose.

 

[nvr-enuf]

Thanks everyone - a friend works at the local (30 mins away) kubota dealer and had a L48 in their shop for service which the tractor did have a cab heater.

Supply to cab heater core is actually the thermostat housing. Right above the temperature sensor which points to the left wheel there is a threaded 3/8" npt fitting which is removed with a number 8 Allen. This is the supply. The threaded plug points to the left rear tractor tire

For the return, I used the threaded plug by the water pump which points straight to the right front tire. Once again it is a 3/8" npt fitting.


Heater works great - lots of heat! Almost too much

I used a maradyne heater I bought off of ebay or amazon. Only mod I did was to change the copper pipes to point straight down vs 90 as built. This made it better for my hose routing

 

[chim]

I would never run anything but metal pipe carrying engine coolant inside the cab of any vehicle.

This is not an efficiency issue, it is a safety issue. If you have ever seen a heater hose let go under the hood of a car, the entire engine compartment is sprayed with boiling hot coolant and steam. If this were to happen inside the cab, the very best outcome would be incredible scalds and years of skin grafts.

If the vehicle were moving at the time, or if you were performing some critical maneuver with the tractor, the chances of a serious vehicle accident in addition to the scalds would be very high.

Curly Dave, Want you to know that I read this post a while back and it prompted me to think about my setup. My heater core sprung a small leak, so I replaced it yesterday. The original core was aluminum and now the same model / same replacement part# comes in copper. This was a great time to revise the hookup and take hard copper outside of the cab for the hose connection. It ended up being a cleaner installation as a side benefit. The white dusty-looking stuff is crumbs from grinding a bit on the Lexan. You may have kept me from getting scorched. Thank you.

 

[Snow Dog]

Nvr-enuf

Would you more being more specific. You are saying the l48 application worked on your stat and WP? I ma trying to look at a schematic to install the 3/8npt on my l3901. This would be a huge help to me to figure out.

Good thinking on changing to straight down. That clears up the clutter and sends the line down behind the seat to the outside in an easier fashion.

 

[robstaples]

My kubota engine ( l39 )threads were 3/8 bsp not npt. Can you get more than 1 1/2 turns? I got fittings from mcmaster carr.

 

[RoyJackson]

I'll add two comments:
a) Heat rises...consider that when locating the heater.
b) If you're going to add a cutoff valve (to shut hot coolant to the heater during the summer months), put it outside the cab.

I have a Curtis cab with the factory heater...came with the tractor when I bought it. It's mounted on the right side approximately level with the loader joystick knob which still allows viewing out the lower right front window (handy for mounting and dismounting the loader).
As someone one in an earlier post, Curtis pre-punches holes for the heater lines. Puts out decent heat, but the Curtis cab on my tractor has plenty of openings to the outside, so I don't get too too hot....reasonably comfortable though. The cutoff valve is located inside the tractor's cab...makes it hot during the summer months, even with the valve closed. I thought about moving the valve, but I think during warmer weather, I'm just going to remove the doors this year.

 

[Snow Dog]

My kubota engine ( l39 )threads were 3/8 bsp not npt. Can you get more than 1 1/2 turns? I got fittings from mcmaster carr.

What is your year of L39?

 

[robstaples]

L39 TLB 2007 ~450 hours This last year (2017) I added a Laurin cab. I tapped into the ports they recommended and I get heat only after the thermostat opens. Will re-examine after this winter season.

 

[Snow Dog]

L39 TLB 2007 ~450 hours This last year (2017) I added a Laurin cab. I tapped into the ports they recommended and I get heat only after the thermostat opens. Will re-examine after this winter season.

I wish I knew who "they" are because Kubota does not take calls and my dealer either knows nothing about the tractor or is hiding it from me. I am 2 hours from an interstate and if I open things up in snow season I have a long day ahead of me. I spoke to the dealer today about the ports and he suggested I use the block heater port...smh. I really appreciate your feed back. On the next warm day I'll start disassembling to take a look. No way my hands will fit in there and my eyes are worse. BTW, if the in port to your heater is after the water pump the heat will be faster. If you reverse the order some heaters will lose 75% of their efficiency.

 

[robstaples]

The "they" in my case was Laurin staff who told me and had included a picure of the engine tap ports for connection the heater hoses. But it was designed before Kubota added the recirculation line to help the block heat more uniformly. But my manual says that recirculation line is closed when the thermostat opens. Seems that it is left to the student to figure out the best connection points. Sharing on this forum will help. Warm weather project.