B7100 HST-E overheats

jacobsmith36

New member

Equipment
Kubota B7100 HST-E
Jan 23, 2023
15
0
1
Mississippi
Hello, I recently replaced my radiator and coolant and added a temp gauge in my B7100 HST-E and it's still overheating. Has anyone else had this problem? Thought maybe it has air in the system but not sure how to check it.
 

85Hokie

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Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,974
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113
Bedford - VA
Jacob,

Welcome to the forum =

First, WHERE you get your "NEW" radiator?

Second, it overheated BEFORE the replacement?

When started cold - take top off radiator, what do you see after about a minute?
 

jacobsmith36

New member

Equipment
Kubota B7100 HST-E
Jan 23, 2023
15
0
1
Mississippi
Jacob,

Welcome to the forum =

First, WHERE you get your "NEW" radiator?

Second, it overheated BEFORE the replacement?

When started cold - take top off radiator, what do you see after about a minute?
The new radiator came from Arko tractor parts on Amazon. It did overheat before but I thought it was because it was corroded and all the fins dented and clogged. I looked in it last night and it didn't look like it was moving any. The belt seemed to be tight enough as well.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
33,429
8,720
113
Sandpoint, ID
The new radiator came from Arko tractor parts on Amazon. It did overheat before but I thought it was because it was corroded and all the fins dented and clogged. I looked in it last night and it didn't look like it was moving any. The belt seemed to be tight enough as well.
Ok your not going to see movement like a normal system.
This is a thermosiphon system, so no water pump and no thermostat.
The belt only runs the fan and dynamo.
Fill the radiator to the top let it run for a bit and look for bubbles.
Where did you put the temp gauge?
 

85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,974
2,828
113
Bedford - VA
Are you sure it is overheating? Is the whistle going off? Have you used an infrared gun to determine what parts are hotter than others?
 

jacobsmith36

New member

Equipment
Kubota B7100 HST-E
Jan 23, 2023
15
0
1
Mississippi
Ok your not going to see movement like a normal system.
This is a thermosiphon system, so no water pump and no thermostat.
The belt only runs the fan and dynamo.
Fill the radiator to the top let it run for a bit and look for bubbles.
Where did you put the temp gauge?
Oh okay that's what I was thinking. I put the sensor inline in the upper radiator hose.
 

jacobsmith36

New member

Equipment
Kubota B7100 HST-E
Jan 23, 2023
15
0
1
Mississippi
Are you sure it is overheating? Is the whistle going off? Have you used an infrared gun to determine what parts are hotter than others?
Mine doesn't have the whistle unfortunately but I could see it spitting air and water out by the cap when it was showing hot on the temp gauge that I added. I didn't try using an infrared gun though.
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
33,429
8,720
113
Sandpoint, ID
These engines are known for cracking the heads when they get overheated.
That's why your looking for bubbles in the radiator when it's running.