Case 780CK Head Gasket for 336BDT

[intheheartofit]

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

 

[Tinkerer]

It will be a lot easier to remove the manifolds first. You may get lucky and the first head you remove is where the problem is. Send me a pm (private conversation) with your email address in it and I will send you the complete service manual for the engine. It has everything you need to know to repair it.

 

[intheheartofit]

Thanks, I PM'ed you. Any tips, worried mainly about breaking manifold bolts as fairly rusty on exhaust side. Also new to engine repair, should I be doing anything else? I see there are complete rebuild kits.

I'm hoping this also takes care of the oil leak, though have a better idea this morning as didn't look last night with impending thunder and lightning as was finishing up.

Anyone have a better place to buy the kit than here:
http://www.agkits.com/Case-A336B-To-S-N-2539000-Cylinder-Head-Set.aspx#.WY5xgRkXbqA

 

[Tinkerer]

The service manual is in your email inbox. Be sure to sort out the 336 specs in it. the specs are in it for ----->
267B, 301B, 3368D, 336BDT AND 401B engines.
For all of your parts contact Dale Weiss at http://e-backhoeparts.com/.
Dale is human encyclopedia of anything made by Case. He sells OEM parts and high quality aftermarket parts.
The manifold studs should not be problem, if any of them are heat the nut cherry red. Just do not go crazy and twist them off. If you can't get the nut off without fear of breaking the stud, cut the nuts off - remove the manifold - hit the stud hard with a hammer a couple of times and it should unscrew quite easily.
If the engine was in decent shape before the coolant problem there isn't any reason to do a complete overhaul. Unless it had a LOT of blow-by out of the valve cover pipe.

 

[intheheartofit]

Thanks for all the info, chatted with Dale today and tried to find the serial number off the engine, but non existent. Dale said take it apart and measure a part of it. Called Case and they said if turbo then definitely the one gasket, I'll do some more research as hoping to open and replace same day as long as heads ok.

Dale said too that my compression should be good as starts with the littlest push on the button. Though I do sometimes get oil out of the blow by tube, just a few drops. Couldn't find the oil leak today from yesterday and was definitely dripping for most of the loads of clay I moved. Will need more observation. Seems like it's covering the blow by tube and leaking over the bell housing, thought maybe turbo, but doesn't look like it.

 

[intheheartofit]

Got it done. Not too bad, took a while as needed to order new fuel injectors but luckily had it under cover. Looks like it solved the compression in the cooling system so far.

What I learned, pretty much all the heads for these engines 336bd 336bdt and the others that use these heads 504? have a crack from the fuel injector into the valve seat. This luckily isn't an issue. Ordered the gasket with the 5.194" fire ring and fit my 336bdt, was a bit worried as Dale said there were two sizes, but Case and where I got it said just one for bdt.

Ended up taking them to a machine shop and got them checked for cracks and since they were there went all out and got the valves done. Cost a grand for everything the including checking two extra heads I had. Think the whole thing was 1500 including new fuel injectors off eBay for 35 a piece, wanted 160 in town, ouch. Basically if anyone does this order injectors if not just swapping gasket as not getting them out straight even the guys at the injector place couldn't get them out without bending.

Everything else is pretty straightforward from the manual. The breather tube and return fuel line fittings were probably most annoying things, luckily had extra tees as easy to mess up the threads.

Didn't retorque head bolts, but should be good as approved by my airplane mechanic friend.

Probably 8 hour job if know what you're doing on the 780ck, probably took me 12-16.

 

[chestypuller]

any way i can get a copy of that manual for a a336

 

[Tinkerer]

any way i can get a copy of that manual for a a336

Check your email inbox. Let me know if you received it ok.

 

[Rayf1]

Any way I could also get a copy of that manual? Doing my head gaskets on my loader and it would come in handy thanks in advance!

 

[Tinkerer]

It should be in your email inbox.