B7100 Cooling Question

[Erik Graham]

Greetings;

My 7100 has an overheating problem. I have read through the archives and have made sure the rad is clear of all debris and that the rad is full. The little "whistle" device doesn't actually whistle but it does have a bit of steam and hot water coming out of it. Engine oil level is fine. There is nothing escaping from the rad cap, but the engine smells very hot after a fairly short run time.I'm not entirely sure how the siphon system works. Is there a thermostat or some other device in the water circulation system? Somewhat puzzling.

Cheers, Erik

 

[Thomas]

How good shape the fan belt??? worn/loose??...have you flush the rad.

 

[charlz]

I have the same tractor. While reading through the archives I came across "Must be 50/50 antifreeze and water!" more than once. Did the problem just start? Did you do any work on the tractor just prior? Like add/change radiator fluid?

Charles

 

[Soundguy]

This wouldn't happen to be a thermosyphon system would it?

Soundguy

 

[charlz]

This wouldn't happen to be a thermosyphon system would it?

Soundguy

Yes, the b7100 is thermosiphon.

 

[Erik Graham]

Greetings;

Thanks for the replies. I have only had the tractor a copy of weeks and haven't got a lot of seat time in as yet, so I don't really know if this is a recurring or a new problem.

Hadn't thought of the 50/50 mix. The first time it got hot I let it cool down and added a quart of straight water, in hindsight that probably wasn't the best choice.

Fan belt looks to be in good shape and and seems to be adjusted correctly.

The only other thing I can think of is that rad might have a build of micro crud. Unfortunately the was the FEL is mounted there is a component that gets in the way of removing the exterior screen. I shone a flash light in there but couldn't see anything obvious but looking at a few other maintenance issues it wouldn't suprise me if it hadn't been blown out since the day the loader was installed.

Lastly, yup it's a thermosuction system. I was wondering whether there is a thermostat somewhere in the system that opens and closes as engine temps flucuate.

Will try the coolant fix first and take another peek at the rad.

Cheers, Erik

 

[M_Brown]

I would remove the exterior screen and check the rad for crud between the cooling fins. Lift the hood and shine a light from the fan side and you should be able to see if it is clear or not. Mine was full of stuff when I bought it. It gets dirty pretty fast if you are working in dusty conditions. Mike

 

[charlz]

Changing the coolant is a quick one. Be sure to look inside the radiator for crud, might need a flush. It's a bit of a pain as the hood doesn't open that far.

When I replaced my lower radiator hose heater (for cold weather starts) it took right at a gallon of antifreeze to refill. I bought the 50/50 premix... costs a little more but manual says to mix the antifreeze and water together before you fill the system anyway. Using premix made the whole process easier.

 

[Soundguy]

Many of the yanmars have thermosyphon systems. In areas where we can get away with it.. we only run 70/30 water/AF.. in cold areas.. we run what we have to for freeze protection. The lower % helps the water circulate better.

soundguy

 

[btolle]

The radiator could have a lot of crud in it that you can't see. I would wait till it cools off completely and then use a hose with a nozzle on it and wash the heck out of the radiator, spraying it from both the front and rear. Wash it long enough to dissolve any layers of dirt that may have built up.

I would also drain the radiator and replace with 50/50 water/anti-freeze. I never trust the last person who owned a piece of equipment no matter how they say they maintained it.

I am assuming you have changed oil/filter and trans fluid/filter.

Bill Tolle

 

[M_Brown]

I agree with Bill. Also You say that it smells hot but does not loose rad fluid. Is the engine clean or does it have alot of dirt and oil stuck to it. I used a product call oil eater that I get form costco. Spray it on when engine is cold and let it sit then wash it off with a hose. Engine comes out looking like new. When the engine is clean you can also see where any leaks are coming from easier. I had one leak and it was where the diesel fuel line connected to the engine. I tighted it and now all I have to ever have to do is an occasional hose it off with water and it is clean. Do it when its cold of course.

 

[LHoyer]

No thermostat in this thermo-syphon system. I put a new rad cap on mine and this helped, along with what the the others have mentioned already.

 

[ribchord]

be carefull.........im looking to buy a b7100 that overheated and cracked the block in the middle cylinder, the cause was the lower radiator hose, it looked fine from the outside but on the inside the innerwall collapsed. change your hoses and see if that helps.

 

[Erik Graham]

Lot's of good ideas. Will be going up the lot this weekend with a bag o' tools and a flashlight to check out all of the suggested trouble spots. Kind of like a murder mystery, lot's of suspects, all having time and opprotunity. Will advise outcome.

Thanks again, Erik

 

[Volfandt]

Good suggestions but I'll expand abit.
On a thermosyphon system, the 1st suspect is always a clogged radiator. Either internal or external.
External is easy to fix but you have to have access and a good air compressor or powerful vaccum to clean it good. This should be part of your annual service procedure. Internally is not so easy.
One way to tell if a portion of the radiator is internally clogged is to feel around it once it's warmed up. An obvious cooler spot is a good indicator of that section not passing hot coolant. It never hurts to run a good radiator flush through it and if that doesn't help and theres an obvious internal obstruction then it'll have to go to a radiator shop for repair.

Also, these types of cooling systems like a higher water to anti-freeze content. 100% water would cool efficiently but would offer no anti freeze or anti rust protection so a 50/50 mix is the most anti freeze you'd want to run.
Good luck