MF 135 Coolant out of overflow

[ezrider93]

I have a 135 diesel that has been giving great service for the 15 years I've owned it. Using it for a short time on Saturday, I noticed coolant coming from the radiator cap vent line. I only ran the tractor for 15 minutes or so, and mostly at idle. The coolant that was coming out wasn't hot at all. I've checked and there are no signs of water in the oil. The radiator cap looks normal with the spring and seal in tact.

I spoke with my trusted tractor doc and he suggested that maybe I have a head gasket starting to go and the pressure is forcing the coolant out. He felt like with the cap off I should see a spurt from the radiator when the cylinder fires. I tried this and didn't notice any spurt.

I should probably mention that there's not a working temp gauge on the tractor. The port the probe goes into is damaged.

Any thoughts or advice is greatly appreciated. I use this tractor every week for mowing my lawn.

[Fordlightning]

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.

[shona13]

hi
Buy a hand held temp thermometer and after using the tractor check the temperature .
Hutch.

[Jerry/MT]

I have a 135 diesel that has been giving great service for the 15 years I've owned it. Using it for a short time on Saturday, I noticed coolant coming from the radiator cap vent line. I only ran the tractor for 15 minutes or so, and mostly at idle. The coolant that was coming out wasn't hot at all. I've checked and there are no signs of water in the oil. The radiator cap looks normal with the spring and seal in tact.

I spoke with my trusted tractor doc and he suggested that maybe I have a head gasket starting to go and the pressure is forcing the coolant out. He felt like with the cap off I should see a spurt from the radiator when the cylinder fires. I tried this and didn't notice any spurt.

I should probably mention that there's not a working temp gauge on the tractor. The port the probe goes into is damaged.

Any thoughts or advice is greatly appreciated. I use this tractor every week for mowing my lawn.

When cold, the coolant level in the radiator should be about 1/4" above the radiator core. The rest of the tank volume is for coolant expansion. If the radiator is overfilled, the coolant will come out of the overflow. So first make sure the coolant level is not too high. If you overfill the rad it will eventually "self correct" by overflowing the exces fuid.

Next warm the engine up with the cap off and look for a continuous stream bubbles in the coolant after the thermostat opens. if you see the CONTINUOUS stream of bubbles it could indicate a leaky head gasket or a cracked cylinder head. You won't see any "spurts" as the engine fires because the firing, even at idle, is pretty rapid.

[ezrider93]

Thanks for the advice. I'll give it a try and post my findings.

[shona13]

Hi
Just other things to check ,although obvious.
Check the radiator core is not blocked or restricted with grass cuttings etc,Fan belt is serviceable and properly tensioned.
If you have doubt,s I would change the thermostat and gasket and while you have the bonnet of give everything in there a good clean generally the most mess comes from the fuel tank cap and the fuel lift pump
You will get a good look at the radiator when the bonnet is of ,which is fairly easy to remove.remove the battery cover, and the headlight wiring at the switch remember where they go ,the six small bolts three each side, the generator pulley guard if fitted ,loosen the two Hinge bolts at the front of the tractor and it will lift of .Note: Generally the Perkins engine needs a real good reason to blow a cylinder head gasket.
Happy Days.
Hutch.

[banjodunn]

G'day I would try a new radiator cap first off. If you have not changed it in the time you have had it then it is prob shot.
Take it into your local auto/tractor parts store to get a new one make sure you check the reach of it ( from the lug that holds it onto the rad to the bottom of the rubber seal) as massey where bad for having different reach caps in the same model.



Jon

[robbb]

If you overfill radiator a certain amount will come out, may not be related but you could try giving your radiator a good clean with an air line .

[ezrider93]

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.

[shona13]

Hi
Check the length of the cap that is lay both caps on the bench and compare the distance in height of the rubber seal ,if they are both the same you can use the 13 lb cap.
Providing all cooling system hoses are sound and serviceable the higher pressure will do no harm ,by using the higher presssure cap means the boiling point of the coolant will be higher .
The temerature range 175--195 is the opening range of the thermostat ,this would be normal running temp, if you were to use the tractor with the radiator cap of the coolant will Boil at 212 F.

Generally the cooling system will produce intermittent bubbles this is due to the water pump circulating the water ,sometimes through a water jacket that has some pretty rough casting flashes inside so I would not be to concerned about the odd bubble .
Another thing to look out for is the water pump there is a small telltale hole in the bottom of the water pump casing if water leaks out of the hole this will tell you that the water pump mechanical seal is leaking and requires replacement ,it may be just as cheap to replace the whole water pump that would be your decision .
happy Days
Hutch.