John deere 7130 impossible issue please help.

Shadow_storm56

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If you are looking for a mystery then this is it, I have been trying to figure out the source of this issue for 2 years now with even JD themselves left baffeled....

I have a JD 7130 that has air behind forced into the cooling system, not exhaust, not fuel mix.....air, First of all there reverse is not true there is no coolant going into any system it should not be which seems impossible but is what is happening. This has an intercooler/heat exhanger so I frist bypassed that and it did not change the issue, I bypassed the pump for the secondary cooling system for a temporary electric pump which did not stop the air but the lower flow and less force behind the return coolant on the secondary system allows the air to get out without taking my coolant with it. ( secondary system shoots a jet of coolant into the overflow/resivoir. This issue does not happen when the engine first starts up it seems to only start once the thermostat opens so whatever is making the pressure is enough to make the coloant tank pressure relief constantly chirp air but not enough to push past a closed thermostat and not enough to build up pressure causing a big surge of air at thermostat opening.

I am so out of ideas the tractor is sitting up there right now and the system is holding this pressure in the cooling system it does not leak back out. How can air be getting in but water not go back out once the source of pressurized air is gone? At one point I was thinking maybe the bottom right main cooling pump was somehow getting sump pressure but I put my finger in the crank vent and let it build a tiny bit but there was no change in the pressure in the cooling system.

Is it possible for the head gasket to have a bad spot in a way that intake air can get to the coolant system but not exhaust and the coolant can't go backwards through the same spot? is there something in the heating system that could generate air pressure when malfunctioning?

Im starting to think someone in the night took apart my block and hid an air compressor inside the engine to try and dry me crazy haha.......

Also thoes saying well it's gotta be the head gasket.... chemical test is negative every time and it's ran for 1000 hours since this issue started plus holds pressure in a leak down test.

I can ignore it and am still using the tractor on this lower flow secondary pump.... I lose coolant at a slower rate with it.

Just for clarify this engine has 3 water pump. One behind the fan for the secondary cooling system, one on the bottom right of the engine and one on the top left of the engine.
 

edritchey

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Sorry I'm no help I hate green tractors they make me throw up 🍻 :LOL: :LOL:
 
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DaveFromMi

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Is your coolant system tight? Pressure test OK? Is there a point in system that is higher than the rad, maybe air pocket that can't get purged? The Techs where I used to work pulled a strong vacuum on the system and let the system pull the coolant in. Can your system maintain a vacuum?
 

Shadow_storm56

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Sorry I'm no help I hate green tractors they make me throw up 🍻 :LOL: :LOL:
This one has served us well as well as our 2 really old deer tractors.... then we had a 5083EN deere that literally fell apart in 1500 hours... so then we began the process of converting to kubota. I can definitely see why people dislike deere now
 
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Shadow_storm56

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Is your coolant system tight? Pressure test OK? Is there a point in system that is higher than the rad, maybe air pocket that can't get purged? The Techs where I used to work pulled a strong vacuum on the system and let the system pull the coolant in. Can your system maintain a vacuum?
Coolant system is tight, perfect pressure test, it's blowing the air out so unless it's a wormhole to a massive air pocket lol..... I haven't tried vaccume but it can maintain pressure.
 
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Fordtech86

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Is it possible for the head gasket to have a bad spot in a way that intake air can get to the coolant system but not exhaust and the coolant can't go backwards through the same spot?
Is it possible, yes. This was one of the issues we had with the 6.0/6.4 in the super dutys, heads lifting under boost. Not sure if it’s your issue or not though.

and also it usually doesn’t show up with a chemical test
 

DaveFromMi

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Coolant system is tight, perfect pressure test, it's blowing the air out so unless it's a wormhole to a massive air pocket lol..... I haven't tried vaccume but it can maintain pressure.
It is possible to have no leaks under positive pressure, but leaks under vacuum. I would focus down stream of the water pump. Maybe the suction side of the pump is restricted creating a vacuum in the system.
 

Shadow_storm56

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It is possible to have no leaks under positive pressure, but leaks under vacuum. I would focus down stream of the water pump. Maybe the suction side of the pump is restricted creating a vacuum in the system.
I put a tire pressure guage on the output of that relief to force it to hold more pressure. Carefully watching it of course.... It stopped at 30PSI.
 

BAP

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Have you tried finding a JD group to post your questions in? If this is a problem others have had with this or similar models, you might get better answers to your questions.
 

Shadow_storm56

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It is possible to have no leaks under positive pressure, but leaks under vacuum. I would focus down stream of the water pump. Maybe the suction side of the pump is restricted creating a vacuum in the system.
I put it under vaccume and it held overnight
 

Shadow_storm56

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O
Have you tried finding a JD group to post your questions in? If this is a problem others have had with this or similar models, you might get better answers to your questions.
Oh theres a thread going there too. The tractor will pass a pressure test and now a vaccume test.
 

DaveFromMi

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What does the coolant system pressure increase to after running the tractor for a while? Can you monitor while running the tractor?
 

Shadow_storm56

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What does the coolant system pressure increase to after running the tractor for a while? Can you monitor while running the tractor?
The hoses start to blow off if it builds past 30 but between 20-30 it's very slow and the engine was hot when I first tested this. I don't think it would go much past 30 by the looks of it. It may not have even quite hit 30 I forgot to make exact note. It held 21 PSI for an hour before I released pressure
 

DaveFromMi

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If the air in the coolant is clean, then the only other possibility is gasket leakage in compression stroke.