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”