new style b7100

[ed1978]

after having major overheating problems....last summer, i removed the radiator....had it steam cleaned, replaced the upper and lower hoses. just came back in the house a few hours ago from mowing my runway, it still overheated. didnt boil over, but lost some from the overflow. and the temp. outside was only 60. there is no waterpump or thermostat on this model. im certain the radiator is clean. have no isues with a blown head gasket....dont see any movement in the top can when its running. 470.00 for a new radiator is my only option. chime in here with possible causes for this occurring. tractor runs fine.....no issues. im getting to the point of buying a john deere

 

[brain55]

Did you take the radiator to a radiator shop? Did you have it flow tested? Did they rod it out? It sounds to me like you only cleaned the exterior, which is important for airflow but has no bearing on fluid flow. Secondly, how do you know you don't have a head gasket or cylinder head issue? It is rare that one of these machines will have a "major" overheating issue and not crack the cylinder head.

Brian

 

[dennisgw]

And you expect a John Deere to better why?

 

[ed1978]

Did you take the radiator to a radiator shop? Did you have it flow tested? Did they rod it out? It sounds to me like you only cleaned the exterior, which is important for airflow but has no bearing on fluid flow. Secondly, how do you know you don't have a head gasket or cylinder head issue? It is rare that one of these machines will have a "major" overheating issue and not crack the cylinder head.

Brian

i work at a race shop....we have a radiator cleaner we submerge them in. i cant see ant movement at all in the radiator when its running....so that indicates no leakage from the cylinders. and my oil is always clean at the same level. and as far as the second post about a john deere, im just getting fed up with kubotas prices....and lack of knowledge when i ask the dealer a question!!!!:thumbsup:

 

[brain55]

i work at a race shop....we have a radiator cleaner we submerge them in. i cant see ant movement at all in the radiator when its running....so that indicates no leakage from the cylinders. and my oil is always clean at the same level. and as far as the second post about a john deere, im just getting fed up with kubotas prices....and lack of knowledge when i ask the dealer a question!!!!:thumbsup:

Personally I would take it to a radiator shop and have them pop the tanks off to see what the core looks like before I spent $400 on a new radiator.

Brian

 

[Egon]

Any way to circulate a radiator flush chemical through the radiator/block and afterwards check the flow through the rad? Might even want to do a reverse flush???

If there is a circulation problem it could also be in the block?

Does the steam whistle work.

 

[ed1978]

Any way to circulate a radiator flush chemical through the radiator/block and afterwards check the flow through the rad? Might even want to do a reverse flush???

Does the steam whistle work.

thats the problem.....the whistle works.....and yes im going to back flush it with some radiator flush first....after that....its off to the radiator shop to see if they can recore it? .....only with larger tubes this time!!!!

 

[Thomas]

Fan belt in good shape also tight,also rad. hose in good shape?

 

[ed1978]

Fan belt in good shape also tight,also rad. hose in good shape?

just put all on new.....

 

[ed1978]

im changing the name to bukota....instead of kubota....:thumbsup:

 

[dennis52]

Did you replace the radiator cap.

This worked wonders for my B7100. Get a genuine Kubota with right psi specs.

Also check for leaks at the Dynamo housing bolts or gasket that joins to the head.

If it overheats the warning whistle should blow (cute)

I have had this happen to me several times working the tractor in 100 degree plus temperatures ( with a now repaired gasket leak) but the tractor has not sustained any damage.

I would not consider parting with this very reliable and popular tractor. It has served me well for 15 years despite neglect and very heavy work in a hot climate.

 

[jimmer2880]

Tractors without water pumps, but with radiators are very touchy on antifreeze/water ratios. IIRC my old yanmar was 60%water to 40% antifreeze. I'm sure someone on here knows better.

 

[Egon]

The less antifreeze to water in the mix the greater the heat transfer.

 

[ed1978]

i love the tractor, bought it new in 1990, just replaced the mower belt last year!!!!! how many tractors can you say work this good??? and i mow alot of grass, no i didnt replace the cap. i have tightened the fan belt, see no leaks around the dyno unit. i am running straight anti freeze right now. i just drained out what i had it winterized with when i steam cleaned the radiator this spring, and put it back in. there wasnt any dirt or anything that come out of the core when i cleaned it either? i thought my overheating was due to the funs being plugged up because i run it one whole summer without the screen on because it fell off and i ran over it chewing it to smithereens!!! and it was p[lugged up bigtime, however it didnt boil over yesterday, it was very close to. it was venting out the overflow. im sure if i dont find the problem when it does get hot this summer it will indeed boil over again. thank you everyone for trying to solve this issue. im not sure where to turn next, going to try a radiator flush next, then dilute the coolant with water .:thumbsup:

 

[Egon]

Window screen on the outside helps catch the fluff and is easy to clean.

 

[ed1978]

Window screen on the outside helps catch the fluff and is easy to clean.

dont have any fluff just yet. and i think they should have mounted the oil cooler in the center of the radiator instead the bottom....this is the important cooling spot for the engine....and its blocked with the oil cooler!!!! jmo

 

[ed1978]

Tractors without water pumps, but with radiators are very touchy on antifreeze/water ratios. IIRC my old yanmar was 60%water to 40% antifreeze. I'm sure someone on here knows better.

yes i do know that the book says not to run straight anti-freeze. i didnt think mine would get hot just mowing my runway when the weather wasnt very warm. perhaps this is my biggest problem!!! will drain it....and add all water....then drain some out and add a little bit of anti-freeze. what good is anti=freeze in the summer anyway if it dont cool?....just corrosion protection?

 

[Bird]

My Kubota manuals said to run a 50/50 antifreeze mix and a factory service rep told me to never go any stronger mix. That was when I had a 1995 B7100.

 

[ed1978]

im thinking more like 60-40....till winter again anyway!!!

 

[ed1978]

im thinking more like 60-40....till winter again anyway!!!

anyway, here is a shot of the original cap....you can see where some of the outer gasket is worn away. otherwise it looks like its sealing good on the inner portion, but im going to replace it, and dilute the anti-freeze, see what happens then. pops says the fan belt isnt tight enough but i disagree with that. if i tighten it anymore than it is, im going to burn up bearings!!!