1971 540b diesel - blows all the coolant out of the cap on cold start

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yes titles wrong its 580b not 540

When i got this thing, it would leak coolant out of the cap on startup. The filler neck looked bent like it hit a branch. I replaced the 1971 radiator with a new one, and the water pump and radiator cap. It didn't have a thermostat so I added a new one.

On startup it began blowing coolant out the vent tube on the radiator cap. I had a new ornamental cap so I replaced that with the cap that came with the new radiator same thing happened.

I removed the thermostat, and still blows coolant out the vent tube on cold start, 2 gallons came out.

On any other vehicle car truck tractor, i have routinely filled the radiator, left the cap off, let it idle until the thermostat opens, and if needed topped it off as the thermostat opens and fluid level drops. This is impossible to do in this case, if the cap is off it will blow out 2 gallons of coolant real quick on cold start at idle.

I'm not familiar with this engine and coolant circuit, but it appears it is pressurizing on start up which is not what I would expect to happen unless something is clogged up somewhere like some coolant bypass circuit.

Prior to installing the radiator I garden hose flushed the block no problem there.

Any ideas on whats wrong here ?

 

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Does this sound like a blown head gasket ?
I have not seen any oil in the coolant or coolant in the oil.

 

[funwithfuel]

So, have you had it up to operating temperature? I recall old Ford trucks with 3208's would blow 2 gallons or more on start up. The sight glass was literally half way down the tank. Maybe you need a recovery bottle and a cap to work with it

 

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I used it to dig a hole on day one and got it good and hot, it never made any noises or anything like it was overheated. But I think it was low on coolant at the time as I didn't have the hood off, you cant see the coolant leaking really with the hood on unless you are looking for it. I don't know, I just suspect this isn't proper behavior lol. I also thought at first well if it had an overflow it could just suck it back, but it seems it is getting pressurized on cold start so I'm now wondering if that means head gasket ?

As I said I don't know the coolant circuit on this perhaps something could be stopped up on a bypass and the water pump[ pressure is blowing it out ?

I don't see that s viable really since it does this with the thermostat out as well.

I think the first question is to be answered by any 580b diesel owners, can you leave the cap off on cold start or will they blow out coolant normally and the cap has to be on at cold start idle ? (and since it is blowing it out the vent tube I don't think this even matters, it appears to be getting pressurized beyond the caps capability.)

 

[funwithfuel]

Overheated diesel almost never make any abnormal sounds as long as they have oil pressure. It's when everything cools, that ugly stuff happens. Head, head gasket, liner and injector cup, these are all things that could have been compromised during your "heat event."
The other possibility is you got one hell of an air pocket. Do you have a pressure tester available? Have you checked the thermostat housing and water manifold for a bleeder?

 

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ok for pressure tester, are we saying pressurize the radiator to a few pounds and see if it leaks down (like it has a blown head gasket or other leak ?), cause I can make a tester for that from tool s that I have.

as for bleeder, do you mean is it leaking coolant anywhere around the housing, no there are no leaks.

 

[funwithfuel]

Regarding bleeder, look for a small pipe plug or legitimate bleed screw. Loosen it up cold to let any trapped air out.
As far as pressure tester just plumb in a gauge and crank the engine over. If the gauge jumps violently, with a cold engine you, have internal leakage.

 

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ok let me check the manual for a bleeder, and i think i may have the stuff to try the gauge test.

since the cap itself isn't leaking but it is coming out the cap pressure vent, i think i can just plumb right to that and see if it is pressuring ? or should i plumb into something like the water temp sensor so I am getting psi direct from coolant circuit and not after it has exceeding cap psi ?

 

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i have another idea, what if i remove the fan belt, and start it, if its blowing water out without a water pump i would think we can rule out everything coolant system related except head gasket or worse ?

 

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i removed the belt
filled the radiator
cold started at slow idle maybe 600 rpm ,very slow
water pulsed out of the open uncapped radiator in time with the engine shooting 3 to 6 inches in the air
blown head gasket?

 

[GregsHD]

Time to pull the head, atleast it's easy access! Just make sure you support the loader good and proper. Also I like your detailed descriptions

 

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okey doke, yeah i think its the head, so tomorrow i will start it and move it about 75 feet from under the shade tree i have been using, to a partially enclosed building cause all the rain has made working on this suck.
i have been going over the info here
https://www.heavyequipmentforums.co...-the-old-ck-would-be-appreciated.71447/page-9
and plan to seek advice here as i tackle this, i have the repair manual but i'm sure it lacks important tips lol.
i have replaced 3 heads before, so i'll be unsure on things like making sure i keep things timed up, any disconnecting of the fuel injector system from the head, i saw make sure the head is not laid flat or damage to injectors.

i think a lot is no brainer take off this and that, but feel free to shout out warnings now as i prepare to remove the head.
thanks all

 

[Delmer]

It could be a cracked head or gasket. There's no cam in the head, pushrods only, so there's no timing to mess up. The injector lines should swing out of the way if you loosen both ends, use a wrench on the injector so you don't torque the injector when loosening the nut. There might be a coolant passage hose under the head that's only replaceable with the head off, replace that. If you don't see an obviously bad head gasket leak to the cooling passages, then check the head next, or have it checked.

 

[funwithfuel]

I would just add, that since you are chasing a compression leak, remove the injectors before removing the head. It'll be much easier to extract from the head while it's still secured to the engine vs chasing it around on your tailgate.
I like your logic in taking off the water pump belt . An old timer showed me that trick about 20 years ago. I completely forgot. Sorry for that.
Good luck , hoping for the best

 

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I'm not understanding how the injectors could be involved in cylinder pressure passing to the coolant circuit. I plan to leave the injectors in place and remove the head, one less thing to mess with reinstalling and messing up. i have a video of the gelled up oil in the valve cover area, pretty impressive, I'm going to have to pull the pan and clean it out too now after seeing it.

 

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I wonder how much running this with no thermostat may have had to do with this gelling mess after coolant began passing into the oil and couldn't get BAKED OUT

 

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[funwithfuel]

Cuz the machine shop isn't going to remove them from the head for free. The nozzle tips protrude below deck. From the tail gate to the machine shop they could be damaged.
By the way, your injector is in a copper sleeve swaged into the head, in most diesels. That copper sleeve is surrounded with coolant. If the cup is damaged, you can get combustion gas in the cooling system. Obviously, by the pic you posted, you have a 2 way street , most likely a head gasket. If you're keeping the machine for the long haul, check everything and confirm your leak. Make sure you verify all critical measurements. Liner height, deck and head flatness
Good luck

 

[Delmer]

You do a compression test through the injector holes. A compression test might be worthwhile before tearing the head off, leakdown test to see where the compression is going.

 

[funwithfuel]

You do a compression test through the injector holes. A compression test might be worthwhile before tearing the head off, leakdown test to see where the compression is going.

Yeah, that too. I shoulda remember that