MF 135 Coolant out of overflow

[Jerry/MT]

Here's an update on my issues. I mowed my lawn using the tractor on Friday and this takes over an hour. I checked the temp about 20 minutes in and was reading about 175F. At the conclusion I was reading about 195F. I didn't observe excessive venting while mowing, but afterward, when cool, I was able to add about 1-1/2 quarts to the system. Today I started the tractor and ran it with the radiator cap off until it got up to operating temp. I did see bubbles come up in the coolant but NOT a continuous stream of small bubbles. It was more like a a few larger bubbles every few seconds.

The radiator is not clogged with debris and the belt is properly adjusted.

One question about the radiator cap, my information lists the cap as being rated at 7lbs. The local auto parts had one that looked like it would fit, but it was rated for 13lbs. Should this be okay?

Again, thanks for all of your advice.

I would not recommend using a 13 psi cap for a cooling system designed for 7 psi. It will raise the boiling point of the coolant but that's not your stated problem. In fact your temperatures look pretty normal for operation at moderate ambient temperatures.

You added fluid so where was the coolant level before you added it? if it was at the top of the radiator cor or within 1/4 inch above of the core, you don't have to add any coolant .

When you saw the bubbles, was the engine at operating temperture and the thermostat opened?

Have you checked for leakage from the waterpump shaft seal and the hoses? Have you noticed any water dropplets blowing out the exhaust (Sometimes a leaking head gasket will cause this.).

[LongJohn01]

Hi Guys,
My MF is overheating.
Any particular grade of coolant for a MF 135? What ratio should the mix be? I've also hear that demineralized water should be used to reduce rusting in the radiator core. Is that an old wives tale?

[murphy1244]

Hi Guys,
My MF is overheating.
Any particular grade of coolant for a MF 135? What ratio should the mix be? I've also hear that demineralized water should be used to reduce rusting in the radiator core. Is that an old wives tale?

Follow your owners manual.

[LongJohn01]

Follow your owners manual.

Don't have one.

[murphy1244]

Get one on e bay, there only less than 20 bucks.

[murphy1244]

Cooling system holds 10.5 quarts, 50 50 mix of tractor antifreeze.

[flusher]

Would agree with the info guy gave you. It could be thermostat, but most likely it's head gasket.

Do you have a temp gun our access to one? To make sure thermostat is operating correctly.

Head gasket leaking and pressurizing the coolant system causing the overflow--that would be my guess.