Disappearing coolant

[Coyote machine]

Tested cap and is fine. Holds a steady 13lbs after 28 years. The longer I run it, the farther down the coolant goes so I'm guessing its a slightly cracked head at the exhaust. Here's a $700 bill for a new head I didn't want.

You won't know for sure it's the head or anything else until you have it apart. It could be a blown out gasket that's just starting to leak into the combustion chambers of the exhaust.

 

[tom4018]

You can buy some UV dye and a cheap black light at some auto parts stores. Put dye in it and run it, you might rule out any external leakage. Not familiar with that model tractor but on some older engines I have seen freeze plugs develop a pin hole on the back of the block seeping out into the bell housing. I would try to rule everything possible out before pulling the head.

 

[arrow]

You won't know for sure it's the head or anything else until you have it apart. It could be a blown out gasket that's just starting to leak into the combustion chambers of the exhaust.

I'm not sure if a diesel with 20-1 compression ratio would be gentle with a head gasket that may have a rift in it. I think the prudent thing for me to do here is nothing right now except to keep it topped off with coolant and keep an eye on things. I'll wait for something more demonstrative to show up before I tear the head off. This is the kind of thing where I won't be satisfied with just a head gasket. I know myself and would replace the water pump, head if it is cracked, of course all the belts and hoses along with the radiator taken off and flushed and cleaned and re- cored if necessary. I could sink $1200 into a tractor that's worth about $7000. Its like waiting under the covers when you were a little kid and waiting for the bogey man to come. Maybe the flashlight will keep him away.

 

[Midniteoyl]

Well, if you remove the head to replace the gasket you could then have the head and block checked for cracks

 

[Coyote machine]

I'm not sure if a diesel with 20-1 compression ratio would be gentle with a head gasket that may have a rift in it. I think the prudent thing for me to do here is nothing right now except to keep it topped off with coolant and keep an eye on things. I'll wait for something more demonstrative to show up before I tear the head off. This is the kind of thing where I won't be satisfied with just a head gasket. I know myself and would replace the water pump, head if it is cracked, of course all the belts and hoses along with the radiator taken off and flushed and cleaned and re- cored if necessary. I could sink $1200 into a tractor that's worth about $7000. Its like waiting under the covers when you were a little kid and waiting for the bogey man to come. Maybe the flashlight will keep him away.

You can do as you chose, however loosing coolant is a sign of things to come. Coolant unlike oil is an etchant and will clean metal instead of lubing it. Gasket is compressed between block and head but can still fail partially, without complete blowout. Most replies have been about leaks or cracks, there's also warping which can occur, which tends to manifest after reaching normal op temperature.

One turbo-diesel Mercedes I fixed had been loosing coolant and no-one could figure out where it was going. After extensive diagnostics had been run with no definitive answers, I found the radiator's plastic header, where it was crimped to the aluminum radiator core was allowing coolant to blow by once the thermostat opened. The fan would dry the area really well so the fluid loss was almost imperceptible. Significantly difficult diagnosis, but success rendered through diligent effort.

Instead of waiting for more reason to do anything you could do an inspection by pulling the head and replace just the gasket, if that's what is bad. You could chose to spend $1200 or whatever, replacing all you mentioned, or more if you let the problem continue to substantial failure. The other side of the coin is you could render a $7K tractor into an unusable tractor.

Turn off the flashlight and get out from under the covers, the bogeyman is already here in the form of your tractor. It won't fix itself, nor will the problem go away with more time contemplating a fix.

 

[Midniteoyl]

Obe Won -

Lou.... Use the dye...Trust in the dye, Lou..

/ Obe Won

 

[Soundguy]

I found the radiator's plastic header, where it was crimped to the aluminum radiator core .

i hate them things....!

 

[arrow]

You can do as you chose, however loosing coolant is a sign of things to come. Coolant unlike oil is an etchant and will clean metal instead of lubing it. Gasket is compressed between block and head but can still fail partially, without complete blowout. Most replies have been about leaks or cracks, there's also warping which can occur, which tends to manifest after reaching normal op temperature.

One turbo-diesel Mercedes I fixed had been loosing coolant and no-one could figure out where it was going. After extensive diagnostics had been run with no definitive answers, I found the radiator's plastic header, where it was crimped to the aluminum radiator core was allowing coolant to blow by once the thermostat opened. The fan would dry the area really well so the fluid loss was almost imperceptible. Significantly difficult diagnosis, but success rendered through diligent effort.

Instead of waiting for more reason to do anything you could do an inspection by pulling the head and replace just the gasket, if that's what is bad. You could chose to spend $1200 or whatever, replacing all you mentioned, or more if you let the problem continue to substantial failure. The other side of the coin is you could render a $7K tractor into an unusable tractor.

Turn off the flashlight and get out from under the covers, the bogeyman is already here in the form of your tractor. It won't fix itself, nor will the problem go away with more time contemplating a fix.

Thanks for your input. My train of thought is to not do anything unnecessary and right now with all the available data, no coolant is leaking into the oil or CO into the radiator. If there is a rift, it is near exhaust and slight at that. I'm looking at a tractor that has a total of 1467 hrs on it in 28 years so I'm weighing in usage to the equation. I do have a funny voice in my head saying "use the dye,use the dye". If I find anything that thus far has not shown up as "a leak", I'll pull the radiator for a complete going over. No, it won't fix itself but certainly I need something more to say it needs a fix with a head removal. That is the very last thing I'll do. What keeps nagging at me is why John Deere sells a coolant as "non evaporative" as if to say what? any other coolant will evaporate?. I need to query the JD dealer about that. I will still need a light however… the uv kind.There is the dye thing.

 

[Recoveryhill]

I've followed this discussion and can't understand why two inexpensive tests have not been performed:

1. Send an oil sample to Blackstone Labs to test for Glycol in the lube oil. This costs $25 and small amounts of Glycol in the lube will total the engine and you won't necessarily see a rise in fluid level. You will also get a read on engine wear by way of metals in the lube fluid.

2. Perform a compression test on the cylinders. Get a cheap compression tester from Harbor Freight and test. If compression is good, that removes the possibility of a blown head gasket and other issues as well.

If it is truly leaking from the water jacket and not entering the combustion chamber or crank case, sure, add water and take your chances. I'd spend the $50 to do the first two tests and not risk destroying an engine.

 

[Soundguy]

I've followed this discussion and can't understand why two inexpensive tests have not been performed:



2. Perform a compression test on the cylinders. Get a cheap compression tester from Harbor Freight and test. If compression is good, that removes the possibility of a blown head gasket and other issues as well. .

last i checked.. the gas compression testers were cheap. no so for the diesel testers. ( not that that would be a reason to NOT own them. even spendy tools have their place ).

at least he did pressure test the coolant system.

at his low rate of loss..I wonder if a comp test on a diesel would show much. might be seen as a nominal difference between cyls if the leak was slight enough.. at 1/4" per hour.. it may be a very minimal leak.

the oil anl. will show if it's hitting oil.. or going out the stack.. with minimal loss.. if really could be either and not seen.. flashed off from both palces before visually signs show..

good luck to the OP..