over heating on a 70 gas John Deere

jdfamily

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I have an old 53 John Deere 70, gas pretty good old tractor. It has been over heating and blowing coolant out the over flow pipe when it gets warm. My questions are, not familiar with the 70, would that be either the water pump or possibly the thermostat. I have not had the tractor long and it sat for quite a while. Is the thermostat located at the upper water pipe where it connects to the radiator? Would a first step be to flush out the whole cooling system?
If so how does one go about changing that. Thanks for any advice.
 
If its new to you at least check the fluid if it looks old flush it. Not sure about that trwctor but are you sure its getting hot or is it just losing fluid when it gets warmed up. A lot of tractors do not like to be topped off. Make sure enough fluid is in to cover fins and maybe stay down an inch unless you are sure its overheating.
 
Do some easy maintenance. Replace the fan belt first. If that doesn't help, thermostat is next. Both are inexpensive and fairly easy to do.
 
(quoted from post at 17:17:39 04/18/18) Do some easy maintenance. Replace the fan belt first. If that doesn't help, thermostat is next. Both are inexpensive and fairly easy to do.

First step would be to tighten the fan belt, real tight.
 
If you have an early 7o and it has not had the thermostat update it is located by the water outlet casting on top of the block. There will be a 2 bolt casting that the thermostat is in. The pipe going to the top of the radiator is o-ringed into this casting. IF your tractor has been updated the thermostat is up close to the radiator. Easy way to tell is if you have 1/2" dia. tube that goes into the water pump from under the hood. It is a bypass which eliminates the problem with temp fluctuation when tractor is first warming up. My fix was to drill a couple 1/4" holes in the thermostat when in original location.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">Is the thermostat located at the upper water pipe where it connects to the radiator?[/i:654c4848f0][/b:654c4848f0]</font>"

No.

Take a look at the THERMOSTAT AND HOUSING diagram below.

a265425.jpg" width="650"


Note the cylinder water outlet (Key 2), thermostat (Key 3), and thermostat cover (Key 6).

Take a look at the photo below of "15" one of our very early 1953 Model 70 gas tractors.

a265429.jpg" width="650"


"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">Would a first step be to flush out the whole cooling system?[/i:654c4848f0][/b:654c4848f0]</font>"

Yes.

"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">If so how does one go about changing that.[/i:654c4848f0][/b:654c4848f0]</font>"

Remove the drain plug from the bottom of the cylinder head.

Take a look at the photo below.

a265440.jpg" width="650"


You might consider refilling the cooling system with a pre-mixed 50/50 water/coolant.

If you decide to replace the fan belt, take a look at the photo below of the new belt installed on "15" after the water pump replacement.

a265442.jpg" width="650"


a265443.jpg" width="650"


Hope this helps.
 
(quoted from post at 16:16:41 04/18/18) I have an old 53 John Deere 70, gas pretty good old tractor. It has been over heating and blowing coolant out the over flow pipe when it gets warm. My questions are, not familiar with the 70, would that be either the water pump or possibly the thermostat. I have not had the tractor long and it sat for quite a while. Is the thermostat located at the upper water pipe where it connects to the radiator? Would a first step be to flush out the whole cooling system?
If so how does one go about changing that. Thanks for any advice.


Ozlander... "First step would be to tighten the fan belt, real tight. "

RM-MN ... " Replace the fan belt first."


LOL! 70's don't have a fan belt (gear-driven fan) and the waterpump drives easily, as long as the belt hasn't broken or fallen off it'll circulate coolant adequately.
 
Thanks so much for the assistance and the pictures of the exact location. That should not be too difficult to remove the entire upper pipe assembly to reach the thermostat. What kind of gasket did you use? My friend said he used a cork gasket that used no gasket sealer, thoughts?

Thanks again.
 
Your right the fan belt comes off and drives the water pump. Water pump seems to be good, will definitely replace the fan belt.
 
"will definitely replace the fan belt"



Once again, it's NOT a "fan belt", fan is gear driven, belt drives the waterpump, and as long as the belt is intact and driving the waterpump, the belt is NOT your issue.

Waterpump drives easily vs. a fan and belt doen't have to be perfect or "fiddlestring tight".
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">What kind of gasket did you use?[/i:654c4848f0][/b:654c4848f0]</font>"

If you are referring to the gasket between the cylinder water outlet, thermostat, and thermostat cover, then one was never used.

Did not disassemble/remove these parts from the tractor.

If you are referring to the gaskets for the water pump, then those two gaskets were ordered from the local Ag Power dealership (Deere).

Take a look at the WATER PUMP AND RADIATOR TANK diagram below.

a265461.jpg" width="650"


Note the water pump housing gasket (Key 12) part no. [b:654c4848f0]F 1053 R[/b:654c4848f0] and cylinder head water inlet gasket (Key 21) part no. [b:654c4848f0]F 519 R[/b:654c4848f0].

<a href="https://www.permatex.com/products/gasketing/gasket-sealants/permatex-form-a-gasket-no-2-sealant/">Permatex Form-A-Gasket Sealant No. 2</a> was probably used with both the gaskets.

a265462.jpg" width="650"


a265464.jpg" width="650"


Hope this helps.
 
James, I wanna know sumthin. Winever someone has trubel with a few models like you have, you can always come out wit a fix fer them, complete wit pitchers and diergrams. My queshthun is- Do you go out inta tha shed an tear down one of yer trackters an start takin pitchers or whhut???
 
(quoted from post at 19:01:38 04/18/18)
(quoted from post at 17:17:39 04/18/18) Do some easy maintenance. Replace the fan belt first. If that doesn't help, thermostat is next. Both are inexpensive and fairly easy to do.

First step would be to tighten the fan belt, real tight.

That will rip the bearings and bushing out of the coolant pump and the generator.
A new belt and probably new pulleys. They will be worn after several decades of use.
 
Thanks for all the information and comments, really helps, especially the schematics.
One maybe dumb question, but have been discussing that with another 70 owner, which
direction does the pump push the water, up the radiator, or pull water from the radiator
to the block? Also any way to check if the water pump is okay before pulling apart the
upper water pipe to get at the thermostat?
Thanks.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">which direction does the pump push the water, up the radiator, or pull water from the radiator to the block?[/i:654c4848f0][/b:654c4848f0]</font>"

Take a look at the illustration below.

a265663.jpg" width="650"




Note the illustration above shows a Model 70 Diesel; however, the flow of the coolant in the cooling system will be the same for the Model 70 gas tractor.

"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">Also any way to check if the water pump is okay before pulling apart the upper water pipe to get at the thermostat?[/i:654c4848f0][/b:654c4848f0]</font>"

When inspecting a Model 70 for possible purchase, checking the cooling system is usually one of the last tests.

After the tractor has run and has been driven for quite some time, I briefly put my hand on the upper water pipe to "feel" the heat.

Then I hold my hand firmly on the lower water pipe to "feel" the heat.

The lower pipe should be comfortably warm.

Next step is to remove the radiator cap and see if the coolant is flowing.

By no means a guarantee the water pump is OK, but should be a good indication that it is working.

Hope this helps.
 
Thanks for that information and advice. Looks like it is easier replacing the water pump. I let it run and it does not seem like the water is moving in the radiator. I just am not able to determine if it is because of the water pump or a stuck thermostat. I will try your suggestions and see if I can tell what is going on.
 
Sorry for all the questions. Had a couple minutes to work a bit on the 70 gas. I let it run to warm up after about a minute it was blowing coolant out the over flow pipe. I felt the upper and lower pipes neither were really warm yet. So what is that telling me?
My thinking is the water pump is working and moving the water, but if I understand it correctly the water pump pushes water into the block and up to the upper water pipe. So if that is the case the thermostat must be open, is that correct? Also looking at the water pump it is the older style which has the smaller lower water pipe which is held in place with o rings rather then the normal hoses and clamps.

Help! Any thoughts on how to approach this would be greatly appreciated!
 

This might sound dumb but how close to the neck of the radiator is the coolant level when the engine is off &amp; cool? There probably needs to be an air pocket in the top of the radiator for the coolant to expand as it warms up.

Mine made a nice mess when I ran it with the level filled to the neck.

You mentioned overheating in your first post. How long does it take to heat up? How hot does it get? Just curious.

Mine needs to be in a sauna with the grill covered to hit 170 (I am in MN)

Carl
 
Thanks I was wondering about that also. The coolant is within an inch of the top. The temperature gauge is not working, so will try
and replace that tomorrow so I can get a read on how warm it is getting. When I feel both the upper and lower water pipes they seem a
bit warm but not hot at all. Like I mentioned I just got this old girl so trying to figure out what is going on. Am hesitant to start
in with either the water pump or thermostat until I know a little more.
Thanks.
 

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