Ford 8N Overheating, or not?

*SOLVED*
See Page 2 for what I did.

Hello,

New here. Been an old Ford car guy for a long time. New to old Ford tractors.

Recently bought an 8N with a Sherman power digger.

I have ran it around some, but noticed something I didn't like. When I start the tractor, it warms up, and operates right in the middle of the temperature gauge. After, say 30 minutes, it starts creeping up slowly, hotter and hotter until finally I shut it off.

2 things:

1. The first time this happened, I did not catch it until I saw some antifreeze has boiled out of the radiator cap and left a wet mark on the hood.
2. Since then, I have shut down the machine every time, but I notice that it just isn't that hot. I can go over and (carefully) open the radiator cap and there isn't really any boiling going on.

My googling brought up on the normal stuff. Thermostat, hoses, radiator fill, etc.

I did a quick test this morning. Started the tractor cold. Looking through the radiator cap, saw almost no flow, but saw a few bubbles pop up during start up. Drove the tractor back to the house, got to operating temp. Removed radiator cap, seemed to see quite a bit more flow. Checked dispstick, no signs of water.

Is this clearly a head gasket problem? Any other checks you would perform?

I have some work to do with the back hoe, and would rather not tear into engine work at this time.

I was always told you can't overheat an engine while it has water in it. Is it okay that I ran this thing until it boiled out of the radiator cap? The radiator is still full of coolant.

This post was edited by Midwayman on 09/20/2022 at 09:43 am.

When cold, the coolant level should be just above the radiator coils.
Gives room for expansion when hot.
When filled too full, it will push coolant out the overflow when hot.

See tips 24, 25 & 35
75 Tips

What was temp of top of radiator and lower radiator hose.

Thanks for the info so far. I did a quick test this afternoon.

Ran for about 30 mins till we were in the hot zone on the gauge.

I put a thermometer in top of radiator to get that reading, then pinched the thermometer between bottom radiator hose and alternator for bottom reading.

The thing started up and ran 15 mins and the radiator top was at around 190F, lower hose, around 130-140F.


After 20 minutes, the gauge was creeping up to "hot", and the top of rad read about 207F while the bottom hose read out at 140F.It was shortly there after I noticed some splashing of something back on the engine:

.

I could not tell exactly what it was, but you can see the top radiator hose outlet is wet like it was antifreeze.

At close to 30 minutes, the temperature at the top of the radiator reads 210, gauge is comfortably in the red "hot" section, and the bottom radiator hose reads, again, 140F.

At this point, it seemed we were bubbling, so I shut down. Didn't see any significant boil-over at this temperature.

This post was edited by Midwayman on 08/15/2022 at 02:45 pm.

Could be a bad thermostat or a badly clogged up cooling system

If the radiator is not overfilled, check for low coolant, a loose fan belt, debris in the radiator fins or a stuck thermostat. A bad water pump will usually
squeak or leak. (If you ever have a water pump start leaking or making noise, replace it immediately. A N water pump will come apart & launch the fan into the
radiator.) And, unless you have a new/rebuilt water pump from a reputable source, it could have impeller erosion. The pump will turn, it wont leak, but it
isnt circulating water.

In order to have a stuck thermostat, you need to have one installed. Squeeze the top hose; if it has a t-stat, you can feel it. Sometimes (rarely) the t-stat
can migrate in the hose & get stuck closed. Or, in an attempt to keep that from happening, some owners will put a third clamp on the hose & tighten it too much
resulting in a stuck t-stat. The OEM top hose came w/ a non-adjustable ban to keep the t-stat in place.

The fan belt should have 1/2 of flex at the mid-point; no more, no less.

Unless you have a pusher fan, blowing out the radiator from the engine side is always a good idea.

If none of that works, you may need to flush the radiator & block.

Get a can/bottle of cleaner from the parts store.

Remove the t-stat from the top hose. Reconnect the hose.

Pour the cleaner in the radiator & run the tractor to operating temp.

Then, remove the bottom hose from the radiator, stuff a rag in the bottom radiator hose connection, & stick your garden hose in the top of the radiator. Turn
the water on (reverse flush) & the water will flow into the radiator, then the block & out of the disconnected lower hose. Let it run until the water is clear.
Then, check the radiator flow. Stick the hose in the top of the radiator; the water should flow out of the bottom w/o backing up in the filler neck. It should
flow at 19.5 gallons a minute. Dont forget to put the t-stat back in correctly!

Use 50/50 anti-freeze & distilled water as your coolant. The anti-freeze contains rust inhibitors, pump lubricant & raises the boiling point of the coolant.

If you do need to get the radiator re-cored, make sure you get the flat fin industrial core. Automotive style cores will clog up w/ debris very quickly.
75 Tips

replace thermostat

60 degree drop is too much, believe you
are not getting good circulation.
Radiator core plugged, Water pump
defective, belt loose, radiator fins
plugged, block plugged, something is
wrong.

You can get a barbed hose adapter that will screw into most air nozzles as you see below. Hook a length of plastic tubing onto that adapter and it works great for getting at and blowing out those radiator fins.

If you don't do that regularly or have never done it, you will be surprised at the amount of crud that will come out of that radiator. Blow out the fins from both sides of the radiator.



This post was edited by Caryc on 08/16/2022 at 09:28 am.

Times two what Abbby said.

While doing some other work on my 9n,I decided that it would be a good idea to flush the radiator. Lots of
goop came out,probably stop leak. Later,when I had to split it for an oil pump rebuild and new cliutch
kit, I powerwashed the coolant channels in the block[very carefully],and gobs more of the goop came out.
The tractor hadn't been getting hot to my knowledge,but had to have hot spots where gobbed up.

Seems logical enough. I will do some testing to look for a blockage. You guys outlines some pretty clear tests to run.

I did notice there was a some green "greasy" residue on the radiator cap. Is this what stop-leak turns into? I have never used the stuff.

If you decide to flush your system there is a valve on the side of the block. Do not just open the valve but take it out to make a bigger opening. You will be surprised what comes out of there. Push water back thru the opening with pressure working back and forth. Not as good as cooking the block but better then nothing.

The stop leak turns into a thick,greasy looking mass with fibers,which makes it a very difficult thing to
remove later. On mine,I had to use small bore brushes with degreaser and a powerwasher[engine was off and
mounted on a stand],even then it was hard to get it all. The radiator had a small leak on the bottom where
the mounting bolts are. Mine is a '41 9n with no pressure on the cooling system.

Ok. Making some progress.


Figured I would start with the tests Bruce outlined along with a tstat check.

With getting the tstat a little more difficult than anticipated. I decided to unhook the hoses and flush the radiator and block to check for clogs.

With both bottom and top hoses off:

Garden hose in top of radiator and good flow flowing out of bottom hose nipple.

Garden hose shove in upper radiator hose nipple of block, got good flow out of bottom block/water pump nipple.

Naturally, I flushed with a lot of water until both were flowing clear. I am assuming this means both are at least mostly working ok.

I did notice my belt is ancient and quite a bit of slop. Unforunately, the alternator is at its max adjustment. Given I have a front loader with hydraulic pump on the front (read: pita to install new belt), i was thinking about cutting the belt and replacing with a link belt. Anyone tried this?

Finally, i wanted to check the water pump. I stuck my endoscope up the bottom water pump nipple. I counted 6 blades that look like this:





I figured now is a time for new hoses, clamps, and tstat. Anything else I should test before reassembly? Also, i have heard the 160f vs 180f debate with old cars. Which is best for these tractors? Know that this has a Power Digger on back, so stationary runtime is the majority.

Thanks for the help. I hope this gets things cooling again.

This post was edited by Midwayman on 08/21/2022 at 12:08 pm.

Off topic a little bit but it is about linked belts. I purchased a 14" Rigid band saw and wanted it to cut to a closer tolerance. I needed to get all the vibration out of it. Believe it or not, putting a linked belt on it did the trick. All belts have thick and thin spots in them. I had heard somewhere that a linked belt would run much smoother and it really did.

Below are the pics when I sliced a .019" slice off of a 4 X 4 hunk of myrtle. It was a consistent .019" from front to back.

Post a pix of your alt and belt.

# 1 rule when diagnosing a heating issue coolant absorbs the heat air takes it away.

You say as long as water is in the block it will not heat...

What happens to plain water at 212 deg... ? That brings up another question how hot can you get plain water ?

(quoted from post at 18:53:03 08/21/22)
Post a pix of your alt and belt.

# 1 rule when diagnosing a heating issue coolant absorbs the heat air takes it away.

You say as long as water is in the block it will not heat...

What happens to plain water at 212 deg... ? That brings up another question how hot can you get plain water ?

Click to expand...

One can get plain water hot enough to where it turns to live steam. Actually live steam is a gas and can not be seen with the eye. When people say they see steam coming out of a radiator, they are not seeing steam, they are seeing condensed steam.

Well, you asked. :wink:

(quoted from post at 15:07:29 08/21/22)
With both bottom and top hoses off:

Garden hose in top of radiator and good flow flowing out of bottom hose nipple.

Garden hose shove in upper radiator hose nipple of block, got good flow out of bottom block/water pump nipple.

Naturally, I flushed with a lot of water until both were flowing clear. I am assuming this means both are at least mostly working ok

Click to expand...

To me, what this means is that you do not have a completely blocked system.

I did notice my belt is ancient and quite a bit of slop. Unfortunately, the alternator is at its max adjustment. Given I have a front loader with hydraulic pump on the front (read: pita to install new belt), i was thinking about cutting the belt and replacing with a link belt. Anyone tried this?

Click to expand...

Many stories of folks doing exactly this.
I personally always remove the pump and shaft to install a quality, correct belt. Good time to inspect the pump to crankshaft pulley connection. Most of these have not been looked at in years, and a lot of them are on their last leg. Splined stinger shafts and hubs often are worn to the point where it's just a matter of time before theyl begin slipping. Pin and rubber bushing connections are often worn so much that the rubber bushings are gone, and the pins and the bushing holes are worn out. Lovejoy connections often have the rubber spiders worn out or gone. Perfect time to fix this area up.

Oh yea, hotter the thermostat, the better

(quoted from post at 09:27:09 08/22/22)

(quoted from post at 15:07:29 08/21/22)
With both bottom and top hoses off:

Garden hose in top of radiator and good flow flowing out of bottom hose nipple.

Garden hose shove in upper radiator hose nipple of block, got good flow out of bottom block/water pump nipple.

Naturally, I flushed with a lot of water until both were flowing clear. I am assuming this means both are at least mostly working ok

Click to expand...

To me, what this means is that you do not have a completely blocked system.

I did notice my belt is ancient and quite a bit of slop. Unfortunately, the alternator is at its max adjustment. Given I have a front loader with hydraulic pump on the front (read: pita to install new belt), i was thinking about cutting the belt and replacing with a link belt. Anyone tried this?

Click to expand...

Many stories of folks doing exactly this.
I personally always remove the pump and shaft to install a quality, correct belt. Good time to inspect the pump to crankshaft pulley connection. Most of these have not been looked at in years, and a lot of them are on their last leg. Splined stinger shafts and hubs often are worn to the point where it's just a matter of time before theyl begin slipping. Pin and rubber bushing connections are often worn so much that the rubber bushings are gone, and the pins and the bushing holes are worn out. Lovejoy connections often have the rubber spiders worn out or gone. Perfect time to fix this area up.

Oh yea, hotter the thermostat, the better

Click to expand...

My 8N does have a real belt on it and it does have a loader with a front pump. It wasn't really a bad job putting a real belt on it.

Not something to be afraid of tackling.

*SOLVED*

So at the end of all of it, the belt tension seemed to be the problem!

I flushed the system, new hoses, new tstat, new antifreeze. Still overheating.

The belt has always been crusty and loose since I bought it. However, it always "seemed" to turn the alternator just fine. Plus, the joint on the alternator was out of adjustment so I could not add any tension without a belt swap.

I cut the old belt off. Figured out that the alternator mounting brackets were home made and not allowing it to swivel for proper tensioning. Did some grinding to fix that so I had more adjustment room.

Installed the link belt. First thing I noticed, is the ammeter went nuts charging. After a hard day of digging with the backhoe (on a hot day!) , the temp gauge stayed right where it should.

Moral of the story: Check the belt tension by hand. Even if it looks like all the pulleys are spinning fine, they may not be.

Thanks for the all the help!

# 1 rule when diagnosing a heating issue coolant absorbs the heat air takes it away.