Case 780CK Head Gasket change in 336BDT

Have a Case 780CK backhoe, think its from 1978. Been pretty good to me so far. Had to do a brake system overhaul of the cylinders and tighten a few things. It had been pretty good till I started it up last year after doing the brakes and coolant came flying out the overflow hose. Weird since it was just sitting for a few days while I worked on the brakes.

Anyways looks like coolant bubbles out of the overflow and if kept below a certain level stops and stays about that level. While doing serious digging though have to top up the water every half hour or less or it'll overheat from drying out.

Tried a bunch of different head gasket in a bottle fixes, but no luck. Which makes sense given the extreme pressure that must be coming from the leaking gasket when under compression and exhaust gases. Oil is black as usual so no coolant getting into that.

I'm looking to sell the machine have a little Kubota that should do the trick after finish a couple more jobs with it. To sell it though I figure to get the most money out of it need to fix the head gasket.

Anyone done one on a 780 or a 336BDT? Can I leave on all the manifolds and just take off the heads and a few other little things then replace the gasket and lower back into place? Though guess might need to take them to a machine shop.

Anyone have a service manual for this machine or engine? I bought the operator manual if anyone needs it, PM me with an email address and I'll send it over. Anyone know bolt head pattern and torque?

I have basically a whole extra 780 as the previous owner had a friend with one that the engine blew and literally took everything off it, heads, manifolds, transmission, cylinders (though probably corroded inside by now), planetaries, literally everything.

Also if I'm doing this job should I be doing anything else engine overhaul related, I see there is kits available? New to rebuilding and engine stuff so mention the little things as I'm probably not aware.

Looks like I'll be doing this sooner than later as well as just started leaking oil from somewhere around the heads tonight.

Thanks for any tips, advice, etc!
Derek

Have to separate the intake manifold, water manifold and exhaust manifold to get the heads off. If no definite cause for the leak from the
gaskets, you will have to look for cracks in the sleeves.

Great, thanks, hoping to order the gasket, no serial on engine so I'll have to see what the inside looks like to know which one though called Case and they said if turbo then definitely only the one, but I'll have to check into that more.