Ford 8N dribbling coolant out of radiator overflow, not overfilled.

[ultrarunner]

Can be loud and easily heard on a busy street… the sound easily modulated by opening the valve for more or less vacuum…

 

[Chanceywd]

I have a 1950 8N too. I have had it for about 28 years. I found early on if I filled it all the way up it was going to spit it out to a certain point.
I've replaced radiator due to running a stick thru, hoses, thermostat, cap and it always goes to a level with the fins just covered. I put a gauge on by tapping in on the left side I think where a drain was many years ago. It never seems to over heat and I work it hard year round. Also replaced head gasket when I did valve job with all new valves about 18 years ago.

Bill

 

[boatmoter]

Hello everyone, first time poster, long time reader.

I am the proud owner of a new-to-me 1950 Ford 8N tractor. Upon purchase, I did the usual maintenance: fresh fluids/filters, new 180 degree tstat, and a new fan belt.

The problem is that once it reaches operating temp, there is a steady dribble of coolant leaking from the radiator overflow tube. I read the 75 tips, and only added enough coolant to just barely cover the core. After about an hour of running, it dribbles out maybe a quart, after that, it stops. This is leaving the core completely exposed once everything cools down.

I have no signs of coolant in the oil, or oil in the coolant. If I add a quart of water to bring it back up to a “proper” level, it just leaks out again. Furthermore, there is no compression in the cooling system that I can tell. No bubbles in coolant, I can cover the radiator fill neck with my hand without feeling compression rushing out.

The belt is properly tensioned for 1/2” of play. I added a temp gauge just before the tstat in the upper rad hose, and the tractor operates within normal temp range, stabilizing around 195-200 degrees f.

Apologies for the long-winded first post, but I’m stumped on this one. Any advice is much appreciated. Thanks in advance!

if it isn't overheating then the radiator cap is defective if it's seeping past the seal to the overflow.

 

[kneedeep]

The overflow jug will work on it. Easy to keep a eye on coolant levels, adding a little when low.

 

[sixdogs]

Just a thought here but is the thermostat in the right direction?
I always start with the easiest thing to check first.

 

[4Liberty]

Reading back through the comments, I did see one that was the best description of what the level should be, and that’s about an inch over the fins. Any more and it’s probably going to push it out when you are working it. Also these are old machines and need levels checked more often than a modern machine. What that means is if you are working it 8 hours it may need checked more than once during that timeframe. With only around a 4lb cap some is going to be lost, and that doesn’t mean anything is wrong it’s just the way it is.

 

[BossofBBQ]

Thanks for all the useful insight guys, I really appreciate it. My new 4 PSI radiator cap from Just8Ns is due in tomorrow.

I believe the thermostat is installed correctly- pointy end towards radiator. No overheating issues either.
I’ll update you guys tomorrow when my radiator cap (hopefully) arrives.

 

[Gord Baker]

Welcome aboard!

Sounds like a bad cap to me.

Cooling systems only work right under pressure- heat expands the fluid. A bad cap won’t make the pressure necessary. That pressure also keeps the coolant from boiling.

I’ve always filled about 1/2 way between the top of of the fins and the cap, seems to work fine for me. Dunno if it’s right or wrong or indifferent.

I don't know if it is a pressurized system or not on those oldies. Suspect Headgasket or cracked block. Keep an eye on Oil colour. Brown is bad.

 

[lilranch2001]

My late father in law gave me his 8N when he was disposing of his acreage after his first wife passed.

It was not in the best of shape, it had sat unused for some years before.
A new ford wiring harness was cheap, easy to install, and solved issues in a great way.
Anyways I have to say I had many more happy hours on that 8N on my new property than I ever did on my ex wife!

 

[BossofBBQ]

Well folks, the new 4 psi radiator cap didn’t fix my issue- but it looks cool and is chrome…
Once the thermostat fully opened, I got a steady dribble of coolant from the overflow tube. I only added enough coolant to barely cover the fins.

One thing I noticed- while doing a cooling system flush, I found that there is no “seal” to the overflow tube. I filled the radiator up to the brim with tap water (engine off) and it immediately dribbled out of the overflow. Should there be some sort of seal there to prevent that? If there’s not supposed to be a “seal” of some sort, then how does the cooling system build the specified amount of pressure with the overflow tube acting as a vent?
There is zero coolant in the oil, or oil in the coolant. Also not burning any coolant that I can tell.

Thanks guys. -the very confused “BBQ”

 

[ultrarunner]

With the cap and adding a coolant recovery bottle the system may be self correcting.

I added these to all my 1960’s cars.

I’m only hoping it’s not a combustion chamber leak from head gasket or cracked iron…

 

[BossofBBQ]

Wouldn't a combustion leak lead to compression in the cooling system? I can remove the cap, cover both the radiator filler neck and the bottom of the overflow tube, and not feel any compression pushing back on my hands with the engine running. Furthermore I can't see any bubbles in the coolant. Should the overflow tube have some sort of seal on it? Mine dosen't. Without a seal, I don't know how it would be possible for the system to be pressurized at all, yet Ford spec'd a 4 PSI cap.....

 

[ultrarunner]

Pressure radiators have the overflow on the neck from those I have seen…

The cap has 2 seals… if the recovery tank is open to atmosphere.

 

[BossofBBQ]

I went out today and took a long, thorough inspection....and I feel pretty stupid now.
I see that the overflow tube is in the neck. I also see that the radiator tank is bent, causing the cap to sit slightly sideways in relation to the hood. It's unclear to me if that is causing sealing issues or not.

I then started the tractor, and removed the radiator cap, watching closely with a flashlight. After the thermostat opened, I saw several small bubbles, but didn't think much of it because I just did a coolant flush; I figured it was just working air out of the system. There is some gunk in the radiator reservoir, but I drained a small sample out of the drain petcock on the radiator and it was bright green, no hints of oil. I'm also not losing any engine oil. It's my first "real" tractor and I'm learning a lot....

What do ya'll think I should do now? I'm shying away from the idea of a coolant recovery system; I'm trying to keep the tractor as original as possible.

 

[ultrarunner]

Anyway to get a better seal at the cap…

Plenty of times I’ve been stumped and then in the course of reviewing found a solution…

Sometimes it’s better to take a break or another set of eyes may provide a missed solution.

Had a guy with an old Ford that ran hot… had the radiator redone and compression checked ok.

I went to see it and he was running way retarded…

Set timing proper and no more overheat… plus right timing boosted the power a lot.

 

[lilranch2001]

No reason to feel stupid.

Asking questions is a big part of TBN, along with pssing off libs!

 

[John0829]

I would check the neck of the radiator closely for cracks or dings that may prevent the cap from sealing properly since you mention it being bent. I would also get a 4 lb. cap from NAPA that does not have the wing on it so there is no possible interference from the hood to see if it still leaks.

 

[gstrom99]

Lets see a closeup pic of the inside of the radiator neck. The cap should seal against a lip. Lip distorted/missing? Wrong radiator?

 

[sixdogs]

When it's running and dribbling, when does the dribbling stop? Does it ever stop? Maybe it just dribbles down to a level and stops?

This has to be an easy solution because Ford N's were loved, but never got much in return. Maintenance was thin and spotty and here we are 75 years later and they're still running.

 

[BossofBBQ]

After taking a break from the 8N (and having a 2nd opinion from my brother) I have observed a few things.
1). A new 4 PSI cap from Napa (without the decorative wing) does not fix the issue.
2). After an hour of run time, it has dribbled out approximately 2 quarts. After that the dribbling seems to slow to a barely noticeable drip.
3) I have attached detailed, close up photos of the radiator fill neck. I believe it to be the correct radiator for the tractor. The fill neck is noticeably bent, which myself and my brother now believe is the cause of my issue. How would I go about straightening it? Would this kind of repair require a radiator shop?