how to tell if Head Gasket is blown?

[rsallen]

Yep, pressurizing only tells you yes, you're in going in the right direction or not. It does not definitively definite the problem.
And yes you're right there are real and multifaceted reasons that may lead one in that direction.

And given the limited information from the op'er I still maintain that the op is 'probably' looking in the wrong place.

 

[Baby Grand]

I've run into head gaskets burn between cyl.'s as well or into an oil gallery.
They don't always burn into the coolant system.

Me too - had a gas burner sucking engine oil into the combustion chamber where the gasket was gone. Real smoker, that one.

 

[skyhook]

Napa auto parts sells a test kit for this, just put it over your rad cap section
and run the machine. It will tell you if you have a combustion leak somewhere.

 

[LD1]

For $35 I think I'd pass on that kit.

And again, it will only tell you if you have a leak into a coolant passage. But it dont tell you it is a head gasket for sure.

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder, blown to atmosphere, or blown into an oil passage and that kit would leave you feeling like everything is good.

 

[skyhook]

For $35 I think I'd pass on that kit.

And again, it will only tell you if you have a leak into a coolant passage. But it dont tell you it is a head gasket for sure.

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder, blown to atmosphere, or blown into an oil passage and that kit would leave you feeling like everything is good.

I disagree,,

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder,
It will detect that, if it blows to anther cylinder, it still has to come out somewhere.

blown to atmosphere, You would "see" this, no need for the kit then.
or blown into an oil passage and that kit would leave you feeling like everything is good.
Nope, you would also see this in the oil.
I mean, you do all your usual test first, visual, etc,,
Look at the oil for water,
look at the rad interior for oil.
Look around the head for leaks,,
but this tester will "sniff" for gases you can't see and should not be there.

 

[rsallen]

There have to be real reasons to even suspect a head gasket to begin with.

We have been given no as in zero info from the op to indicate a head gasket problem of any sort.
If we start going through all the different symptoms and scenarios that head gaskets go or all the ways we've seen them blown all we'll do is completely confuse the man and send him to places he may not need go.

Let's start with how the tractor is acting, the model, the year and hours.

 

[skyhook]

He did say he would like to rule out a "head gasket' issue in his first post.
This is the info members have given him.
But I do agree with your post.

 

[LD1]

I disagree,,

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder,
It will detect that, if it blows to anther cylinder, it still has to come out somewhere.

blown to atmosphere, You would "see" this, no need for the kit then.
or blown into an oil passage and that kit would leave you feeling like everything is good.
Nope, you would also see this in the oil.
I mean, you do all your usual test first, visual, etc,,
Look at the oil for water,
look at the rad interior for oil.
Look around the head for leaks,,
but this tester will "sniff" for gases you can't see and should not be there.

You are naturally going to have leakage to the oil pan no matter what VIA ring gap. Do I guess I dont fully understand how the test can distinguish between just normal leakdown to the crankcase via the rings, or a leak to another cylinder or oil passage??

 

[skyhook]

You have me a little confused there, LD1,,
Like I said, if there's a "leak down" past the rings, then thats another story, not the head gasket.
The kit I shown will only test "sniff" for combustion gases in the coolant,
something that you nor I could actually smell.
If you see oil in the coolant, or see coolant in the oil,
then you wouldn't need this kit, you already have an "indication" of a faulty head gasket.
Also, if you have a "leak down" as you put it,, past the so called ring gaps,
you have major problems, in which case, you'll be changing the head gasket also.
In any case, I hope the OP gets this fixed without to many major expenses.:thumbsup:

 

[LD1]

Let me start by saying I dont know how that kit works. You say it is just a sniff test that checks the coolant for combustion gasses right??

Well when I said that IF it passes that test the gasket could still be blown. Just not blown to coolant. IT could blow to another cylinder, or blow to an oil passage. And you said it would detect that, it still has to come out somewhere.....

I dont see how a coolant sniff test would detect a cylinder to cylinder gasket leak?