No heat L4630

Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Last year my 4630 wasn't throwing any heat. Found the coolant low, filled it up and all was fine. This year, no heat and the coolant is full (tried adding and it wouldn't take any). Any suggestions?

I've had this tractor 3 years, 2200 hours on it. I've greased it, had the hydraulic fluid and filters changed, changed engine oil and filter. Not very mechanical.

Thanks for any suggestions.
 

85Hokie

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Can you test the hose temps as it moves away from the head/block ?
 

fruitcakesa

Well-known member

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M 6040
Oct 26, 2010
856
270
63
Cavendish Vermont
I had the opposite issue but it could be from the same problem.
The heat valve stuck open both my old L4630 and current M so heat was always on even with AC on.
All the climate control plumbing for this is under the seat in the M and in the roof of the L.
I accessed the heater hose at the heater and put a ball valve in line so I can turn off the heat in summer and on in winter.
I am not sure of the fix for your problem but you can at least check it to see if it might be the valve.
I don't know where the actual valve is so a parts breakdown might help find it.
 

DaveFromMi

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Equipment
L3901 RCR1260
Apr 14, 2021
614
531
93
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Does the temp gauge indicate as expected? Does coolant ever warm up?
Water pump maybe not turning?
 

Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Sorry for the delay here. I decided to try adding coolant again. I used a funnel the first time but didn't this time. It took about 1/2 gallon this time and when I tried the heat it was working fine. The temp gauge might have been a bit higher then normal when I ran it prior to adding coolant. I park the tractor inside and don't see any coolant on the floor. Begs the question of where the coolant is going. Head gasket comes to mind but no foamy or milky or discolored oil. Maybe it is leaking out the head gasket and turning to steam (as a friend suggested) which may be the case because there is a smell when the tractor is running that seems "different."
 

Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Still no luck chasing down where my anti freeze is going but maybe today was a clue. I ran the tractor today with outside temps in the low 40's. My windows were fogged on the inside and I realized that my windows are always fogged on the inside. Regardless of outside temps, If I am running the heat I have fogged interior windows. I have owned this tractor 4 (or is it 5) years and the interior windows are always fogged up. Any chance the disappearing coolant and the fogged windows are the same problem?

As a side note, a mechanic buddy suggested I visit an auto parts store for an additive for the coolant that shows up in a black light. Run the tractor for a week or so with the additive and then go out in the dark with a blacklight and if there is a leak it will show up. Hmmmm.
 

DaveFromMi

Well-known member

Equipment
L3901 RCR1260
Apr 14, 2021
614
531
93
Indiana
If it is somewhat oily and difficult to wipe off, it is coolant. If so, something in the cab is leaking coolant. Probably the heater core.
 
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Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Thanks for your replies Fruitcakesa and DaveFromMi. I'll take some time this weekend to remove the top and a check things out. I haven't noticed the fog being oily or difficult to wipe off and I don't know what antifreeze smells like so maybe I have two different issues.

On a happier topic I ordered a plow for the front of the tractor yesterday. Should be here mid January. : )
 
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Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Well, old thread, same problem. Still have disappearing coolant. It's an L so finally took the top off and investigated. Opened up the heating/cooling system. Other than being dirty I couldn't find anything amiss. I started the tractor and let it run awhile. The heater core didn't warm up (I had the heat turned on). I will try letting it run longer today and bring out the laser thermometer to check around with.
 

DustyRusty

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2020 BX23S, BX2822 Snowblower, Curtis Deluxe Cab,
Nov 8, 2015
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Most likely a heater core leak. Did you try the dye to see if it shows anything? It can be as simple as a loose clamp, or as bad as a cracked nipple where the hose enters the heater core. A good cooling system pressure tool is the best way to find it. Under pressure, you will see the leak.
 
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Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Most likely a heater core leak. Did you try the dye to see if it shows anything? It can be as simple as a loose clamp, or as bad as a cracked nipple where the hose enters the heater core. A good cooling system pressure tool is the best way to find it. Under pressure, you will see the leak.
Thanks DustyRusty. I did not get a chance to try the dye or even get time to check things out this summer. I was able to let it run longer this morning (4 bars on the temp gauge). The heater core did get warm. I saw no evidence of leaks up top (heater core, hoses, etc...). So, I took a longer look and found a leak on the "passenger" side of the engine, at the rear, in what I believe is head gasket territory. Just noticed a bit of wetness there and with a longer look noticed steam/vapor coming out right at that point. Along the head gasket seam forward, I could see some white buildup maybe indicating its been leaking and boiling off and leaving something behind. If this is the cause of the disappearing antifreeze (and the resultant loss of heat) I am glad I found the cause. On the other hand, replacing a head gasket is way beyond my pay grade and will likely be $$ to have done.
 

Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
I am blessed to know a diesel mechanic who is willing to replace the head gasket for me. He said he will stop by Saturday to get whatever numbers he needs off the engine to order the gasket. I'm keeping a close eye on the dipstick in the meantime, before and after use. We are just getting into our snow season here (UP Michigan) so I need the tractor (front plow, rear blower). I'll be putting the chains on the rear soon. Bought studded chains last year based on recommendations from you folks on this forum.
 
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GreensvilleJay

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Apr 2, 2019
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sure glad you FOUND the reason for the loss of coolant ! Also GREAT to have a friend do the repair for you, should save a LOT of money and time.

take some time BEFORE the job is to be done, to clean up the garage, sweep the floor, organize tools, empty the workbench, add lighting, etc. The easier you make it for your mechanic, the faster you'll have your tractor 'up and running' !
 
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Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
sure glad you FOUND the reason for the loss of coolant ! Also GREAT to have a friend do the repair for you, should save a LOT of money and time.

take some time BEFORE the job is to be done, to clean up the garage, sweep the floor, organize tools, empty the workbench, add lighting, etc. The easier you make it for your mechanic, the faster you'll have your tractor 'up and running' !
Solid advice! Will do.
 

Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Well, AFTER we changed the gasket (12 hours total) we discovered the head has a hairline crack in the back corner. Added some Bars for now and the new head is on its way. Could not detect the crack while the head was off.
 
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Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Well, the new head is installed and all is well. The engine sounds better running now than it has for the whole 4 years I've owned it. Even a few small things buttoned up along the way like the injectors had been leaking, now taken care of. DK Engine Parts was really good to work with. They shipped the head and I had it in 3 days. Packaged well and fit and finish were excellent. Got er done just in time for a winter watch forecasting 6" of snow over the next couple of days.

Merry Christmas, Happy Holidays to all.
 

fried1765

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Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
Nov 14, 2019
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Well, the new head is installed and all is well. The engine sounds better running now than it has for the whole 4 years I've owned it. Even a few small things buttoned up along the way like the injectors had been leaking, now taken care of. DK Engine Parts was really good to work with. They shipped the head and I had it in 3 days. Packaged well and fit and finish were excellent. Got er done just in time for a winter watch forecasting 6" of snow over the next couple of days.

Merry Christmas, Happy Holidays to all.
Congratulations on the GOOD NEWS!
Merry Christmas !!!!!
 
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Bill in the U.P.

Member

Equipment
L4630 GST
Dec 31, 2020
80
18
8
Michigan
Update: The heat has been working fine since the head install. The window steaming has stopped too. That is a big deal as I can only imagine the damage to health breathing antifreeze vapor could cause.
 
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