Overheating (radiator/thermostat related)

[taedog]

So early last year (spring) my Ford 8N blew a leak in the top radiator hose so I replaced it and installed a new thermostat (in the correct direction - pointy piece facing the radiator) and the tractor ran all season until this winter started overheating and it was determined to be a bad thermostat which I confirmed by boiling it and replaced with another new one (in the same direction).

Ever since I replaced the thermostat, the tractor still overheats and starts to stall out, the following is an odd sequence I've repeated which may help determine the root cause...

1. Tractor stalls or I park it after running for 5-10 minutes (spreading manure)
2. I slowly turn the radiator cap to allow pressure to escape
3. Air pressure is released pretty quickly (no coolant escapes except for a few drops sprayed)
4. Once pressure is released, I hear glugging into/out of the radiator (possibly the thermostat finally opening??)
5. This last time, a good bit of "smoke" poured out of the radiator cap (that was not off but wasn't fully closed either) (no smoke prior to opening cap, just pressure)

It seems like the thermostat is not opening once the engine is warmed up and only opens when I open the radiator cap, which seems unlikely to be related, but has happened too many times to just be a coincidence.

Anyone have a clue what's happening? This new thermostat was boiled tested to 180 degrees appropriately and this was happening as soon as it was installed so I am pretty hesitant to think it immediately went bad.

Help please

 

[Factotum]

Have you tried to run it without the cap on and look for flow once the thermostat opens? This would test the thermostat and water pump.

 

[wore out]

So early last year (spring) my Ford 8N blew a leak in the top radiator hose so I replaced it and installed a new thermostat (in the correct direction - pointy piece facing the radiator) and the tractor ran all season until this winter started overheating and it was determined to be a bad thermostat which I confirmed by boiling it and replaced with another new one (in the same direction).

Ever since I replaced the thermostat, the tractor still overheats and starts to stall out, the following is an odd sequence I've repeated which may help determine the root cause...

1. Tractor stalls or I park it after running for 5-10 minutes (spreading manure)
2. I slowly turn the radiator cap to allow pressure to escape
3. Air pressure is released pretty quickly (no coolant escapes except for a few drops sprayed)
4. Once pressure is released, I hear glugging into/out of the radiator (possibly the thermostat finally opening??)
5. This last time, a good bit of "smoke" poured out of the radiator cap (that was not off but wasn't fully closed either) (no smoke prior to opening cap, just pressure)

It seems like the thermostat is not opening once the engine is warmed up and only opens when I open the radiator cap, which seems unlikely to be related, but has happened too many times to just be a coincidence.

Anyone have a clue what's happening? This new thermostat was boiled tested to 180 degrees appropriately and this was happening as soon as it was installed so I am pretty hesitant to think it immediately went bad.

Help please

A head gasket leak would be ONE explanation for what you are observing.

 

[taedog]

Have you tried to run it without the cap on and look for flow once the thermostat opens? This would test the thermostat and water pump.

No I haven't - but its an easy test - can you explain more about the water pump? i didn't know there was one (there's a lot i don't know)

 

[taedog]

A head gasket leak would be ONE explanation for what you are observing.

Thanks, can you explain more about that and how to diagnose if that was the case?

 

[HFJ]

"allow pressure to escape"

that's the cap's job. did someone put the wrong cap on it?

 

[taedog]

"allow pressure to escape"

that's the cap's job. did someone put the wrong cap on it?

Same cap i've had on it since i got it years ago - it has like a half twist to secure it

 

[HFJ]

Same cap i've had on it since i got it years ago - it has like a half twist to secure it

maybe it's gone bad. try running with the cap just sitting there but not tightened down and see what happens. iirc, they should only hold 4 psi.

 

[taedog]

maybe it's gone bad. try running with the cap just sitting there but not tightened down and see what happens. iirc, they should only hold 4 psi.

Thanks, just ran it for a few with cap loose and seemed to work better but will have to do a real test tomorrow. The spring definitely seemed rusted and way tighter than for 4 psi.

Would the cap not venting prevent the thermostat from opening? or coolant from flowing to the block?

 

[Eman85]

Thanks, just ran it for a few with cap loose and seemed to work better but will have to do a real test tomorrow. The spring definitely seemed rusted and way tighter than for 4 psi.

Would the cap not venting prevent the thermostat from opening? or coolant from flowing to the block?

NO
Run the tractor with the cap off and observe the coolant. Do you have a thermometer or a non contact gun that you can take temperature with?
Why does the tractor stall?
Smoke doesn't come out of a radiator, generally steam might.

 

[taedog]

NO
Run the tractor with the cap off and observe the coolant. Do you have a thermometer or a non contact gun that you can take temperature with?
Why does the tractor stall?
Smoke doesn't come out of a radiator, generally steam might.

I'm not sure exactly why it stalls - i'm assuming overheating as the engine block is super hot (paint getting burnt off it) so i'm assuming no coolant is flowing through it. Once it stalls it won't start for a few hours after.

It seems as though when I loosen the cap, I can hear coolant start glugging around so i'm thinking either the pressure build-up is causing either the coolant to not flow or thermostat to not open. If I was low on coolant would that effect it? Or maybe the radiator is not circulating it?

 

[Eman85]

I'm no good at guessing games.
Run the tractor with the cap off and watch the water. Radiator just sits there, it doesn't circulate anything the water pump does. Check your fan belt, it is what turns the water pump which is what the fan attaches to.

 

[Tim PloughNman Daley RIP]

So early last year (spring) my Ford 8N blew a leak in the top radiator hose so I replaced it and installed a new thermostat (in the correct direction - pointy piece facing the radiator) and the tractor ran all season until this winter started overheating and it was determined to be a bad thermostat which I confirmed by boiling it and replaced with another new one (in the same direction).

Ever since I replaced the thermostat, the tractor still overheats and starts to stall out, the following is an odd sequence I've repeated which may help determine the root cause...

1. Tractor stalls or I park it after running for 5-10 minutes (spreading manure)
2. I slowly turn the radiator cap to allow pressure to escape
3. Air pressure is released pretty quickly (no coolant escapes except for a few drops sprayed)
4. Once pressure is released, I hear glugging into/out of the radiator (possibly the thermostat finally opening??)
5. This last time, a good bit of "smoke" poured out of the radiator cap (that was not off but wasn't fully closed either) (no smoke prior to opening cap, just pressure)

It seems like the thermostat is not opening once the engine is warmed up and only opens when I open the radiator cap, which seems unlikely to be related, but has happened too many times to just be a coincidence.

Anyone have a clue what's happening? This new thermostat was boiled tested to 180 degrees appropriately and this was happening as soon as it was installed so I am pretty hesitant to think it immediately went bad.

Help please

Do you have a fan belt tensioning bracket attached to your GENERATOR or ALTERNATOR? You must maintain proper fan belt tension on the system, one to charge the battery, and two, to operate the cooling system. You cannot do either function without correct belt tension. Failure results in a dead battery in short order and possible damage to the water pump. Overheating is inevitable at that point. Do you havre the band on upper hose to keep Thermostat in place? Correct RAD CAP?

Tim Daley (MI)

 

[Btzj02]

The first time I replaced the thermostat on my 8N51 I inserted and secured the thermostat too far from the engine head. My symptoms were periodic burping of the coolant into the radiator. As a result I repositioned the thermostat closer to the engine head and secured it better with a new hose clamp. Seems to have cured my problem!

 

[Jim L WA]

taedog, welcome to the forum. This might be out there, but if the top hose sprung a leak, check that the bottom hose isn't collapsing.
The stalling after 5 or 10 minutes may not be related to the overheating, but a coil or condenser going bad.

 

[Tim PloughNman Daley RIP]

So early last year (spring) my Ford 8N blew a leak in the top radiator hose so I replaced it and installed a new thermostat (in the correct direction - pointy piece facing the radiator) and the tractor ran all season until this winter started overheating and it was determined to be a bad thermostat which I confirmed by boiling it and replaced with another new one (in the same direction).

Ever since I replaced the thermostat, the tractor still overheats and starts to stall out, the following is an odd sequence I've repeated which may help determine the root cause...

1. Tractor stalls or I park it after running for 5-10 minutes (spreading manure)
2. I slowly turn the radiator cap to allow pressure to escape
3. Air pressure is released pretty quickly (no coolant escapes except for a few drops sprayed)
4. Once pressure is released, I hear glugging into/out of the radiator (possibly the thermostat finally opening??)
5. This last time, a good bit of "smoke" poured out of the radiator cap (that was not off but wasn't fully closed either) (no smoke prior to opening cap, just pressure)

It seems like the thermostat is not opening once the engine is warmed up and only opens when I open the radiator cap, which seems unlikely to be related, but has happened too many times to just be a coincidence.

Anyone have a clue what's happening? This new thermostat was boiled tested to 180 degrees appropriately and this was happening as soon as it was installed so I am pretty hesitant to think it immediately went bad.

Help please

OK, Taedog, looks like you are a newbie around here anyway. New to FORD TRACTORS too? Any prior experience working/operating tractors? engines? You have other problems than with the cooling system. Radiator plugged? Have you had it cleaned? How can you possibly not know what a water pump is and how and why it operates? You should not release the pressure on the radiator while it is hot first of all. A good new Thermostat is set at 160 DEG. but not all suppliers are created equal so it matters where you buy from. NOTE my previous post with pictures. You need to check the FAN BELT TENSION. Poor incorrect fan belt tension will cause, #1, battery can never get charged, and #2, cooling system failure is inevitable. Your GENERATOR or ALTERNATOR MUST have a tensioning bracket affixed to have belt tension set properly. Start there. I highly advise you invest in the ESSENTIAL MANUALS for your 8N and read them religiously before doing any more work on it. If'N ya wanna be a FORD TRACTOR owner you need original or copies of these:

1. 8N OPERATOR's Manual
2. '39-'53 MPC (Master Parts Catalog)
3. I&T F0-4 Service Manual
4. Service Manual for Mechanics (OPTIONAL)

You should have the 8N RADIATOR, p/n 8N-8005-A and the SHROUD, p/n 2N-8146. Radiator Cap is p/n 2N-8100. Should only use an OEM style cap. System is a 2 PSI feature.

Tim Daley (MI)

 

[Bruce(OR)]

My 2 cents.
Last I heard 4 PSI rad caps were no longer being made. 7 PSI is the lowest you can go with a new one. Don't.
Your machine does not have an overflow jug to catch excess coolant. Do not overfill the rad. Coolant level just above the fins.
That big air section in the top tank above the fins is for expansion.
If you can't find an old cap and your stuck with a 7 PSI cap, you might consider removing the rad cap lower rubber seal at the fill neck.
Yes, the one closest to you when looking at it upside down.
T-stat was originally installed 1/2 way in upper hose, then clamped in place to prevent movement.
I go one step further and drill a hole in the stat someplace, 1/16" to allow air to travel through on initial install. Look at your better quality stats for cars. You should see a "Piddle valve" that allows air to escape and a low amount of fluid. This slight flow also allows the stat to open more evenly.
Burning daylight and gotta run.
Catch you later.

 

[Tim PloughNman Daley RIP]

My 2 cents.
Last I heard 4 PSI rad caps were no longer being made. 7 PSI is the lowest you can go with a new one. Don't.
Your machine does not have an overflow jug to catch excess coolant. Do not overfill the rad. Coolant level just above the fins.
That big air section in the top tank above the fins is for expansion.
If you can't find an old cap and your stuck with a 7 PSI cap, you might consider removing the rad cap lower rubber seal at the fill neck.
Yes, the one closest to you when looking at it upside down.
T-stat was originally installed 1/2 way in upper hose, then clamped in place to prevent movement.
I go one step further and drill a hole in the stat someplace, 1/16" to allow air to travel through on initial install. Look at your better quality stats for cars. You should see a "Piddle valve" that allows air to escape and a low amount of fluid. This slight flow also allows the stat to open more evenly.
Burning daylight and gotta run.
Catch you later.

Don't think so Bruce. The 4 PSI Cap, p/n 1T-8100-A was used from '53 thru '64. Check with Denny Carpenter, $12. The N-SERIES from 2N thru 8N used the 2 PSI radiator system, cap p/n 2N-8100. FYI: Early 9N used a non-pressurized radiator and a STANT Cap. Cap and parts do not interchange with the later 2 PSI 2N/8N RAD.

Tim Daley (MI)

 

[Bruce(OR)]

"Last -- "I" -- heard 4 PSI rad caps were no longer being made."
Didn't know about those suppliers.
Mea Culpa.