Grain truck needs some help

[IaGary]

This truck was bought new by dad in 1976.

It has just under 40,000 miles and has developed a problem. Its losing antifreeze from the radiator and I don"t know where.

It has a 361 gas motor and I"m afraid its a head gasket or worst yet maybe a cracked head.

It looses about 1 gal a day.

Still runs strong. We haul 10 loads a day to the elevator 10 miles away and need to run about 5000 more bushel to town. Two small days.

Anyone have any experience with this motor?

What would you look for before tearing it down?

No puddles on the ground or wet spots under the hood.

 

[olddog]

Presume you have already checked the oil for overage and heater core, gotta be goin' out the exhaust. Sweet smellin' and white cloud exhaust?
If not in the oilpan, would finish haulin', then tear 'er down.

 

[Allan in NE]

Hi Gary,

Look real close at that water pump weep hole. Could be you're loosin' it when out on the road.

Either that, or just give me a call and I'll come get 'er. What a nice truck! :>)

Allan

 

[IaGary]

Oil is fine. No white smoke out the exhaust.

I put a new water pump on 2 years ago.

Also no bubbles inthe radiator.

If its burning water real slow will there still be a smell and white smoke?

Gary

 

[VADAVE]

Had a problem like that, changed everything din't fix it.
Turned out it was the radiator cap. It had lost spring tension and ran fine until the thermostat opened then would just "pump" coolant out the ovwerflow hose. Didn't leave a spot on the ground because the vehicle was moving and when I stopped it had pushed out all it could or it would cool off just enough.
The one thing I didn't think of and the cheapest to fix.

 

[IaGary]

Hey thanks never thought of the cap. But there has been just a little damp spot by the outlet.

But I'm not usually that lucky but it's worth a try.

Gary

 

[Anonymous-0]

May not show during a hard working application. Would be most obvious on startup, after, lets say, a 15 min cooldown after a good pull. Also, another hole for it to get out, is the rad overflow/press cap.

 

[armand tatro]

Lift the hood after loaded trip and check all hoses for leaks. I had a 290 cummins leaking water but could never find it util I tilted hood at the end of the day with the engine still running and a heater had pinholes squiting water towards the head gasket and evaporating with hardly a trace. Replaced hoses and no more water loss. Would only leak under pressure. Armand

 

[JT]

Gary,
When you take off the radiator cap, do you see any oily residue in tha radiator? if not, probably not an engine problem. Check all you hose connections, make sure your hoses have not shrunk from age and became loose. If you are still concerned, get a can of Barrs leak and put in the radiator, that stuff will seal up cracked heads or leaking head gaskets with water loss you are describing. I would also check cap, and look around bottom of radiator to make sure you do not have a pin hole leaking, again, Barrs leak will stop that. My dad had a 1976 F750 with a 361, was a good engine, he used it in a fertilizer spreader truck, so it got a lot of engine time, but not a lot of miles. never had any trouble with it.
Good luck
Jim

 

[1936]

If your radiator is still from 1976 it has been a good one and a time for a change. I have had water pumps replaced and not make it home on the new pump. If you can smell anti freeze walking up to the truck when it is hot you have radiator leak.

 

[Anonymous-0]

hey; Gary get under the old girl and check the soft plugs had a chevy doing the same thing could not find the leak, fill her up with water and about three to four days I'd have to add more water finally found the leak soft plug behind the starter was leaking. hope you find it Jer

 

[Roy Suomi]

Have someone put a radiator pressure test on the cooling system..Takes only a couple of minutes..Could be burning coolant or could be leaking it..I've had super luck with the "old" Fords..This last one is a weak link [330] with aux trans and 10:00-22.5 rubber on it..All my 361's ran strong..Even had one run 11,000 miles with a broken crankshaft..Bought it used , had a slight "rumble" in it and had low oil pressure..I pulled it and turned it over and found the crank was broken..Found it broken across the front main journal..Installed a regrind crank with bearings..Not good on gas , but they will run....

 

[Jerry Cent. Mi.]

If it was burning that much Antifreeze while it was running the exhaust would smell like you were making candy and it would produce a visable fog like cloud in the air. That is what I noticed about a car that needed a new head gasket.

 

[Old Ford Mechanic]

Gary,May not be your trouble but,Ive seen many a water pump leak at the weep hole under the housing just behind the pulley.Allan's been there and done that too.You won't think its leaking there at all until you crawl up under with a light.Find the weep hole and look for a water stain around the hole.If its been leaking you will see the telltale sign.It will be visible on the ground when the weather gets colder.In the morning after the truck sits at night is the best time to do your ispection.

 

[Chad Franke]

Might not smoke, but if it"s burning antifreeze you will see the deposits on the spark plugs.

 

[Anonymous-0]

Gary I had a leak in my 75 F750 and couldn't find it .Anyway I had a friend who is a GM engineer and He said get some Black Pepper about 1/2 regular size can and pour it in the radiator [ITWorked ]No more Leaks He said they do that at Gm Factory all the time to stop leaks Just My thoughts TOM