Hello all, I've been reading the forums here and recently picked up a D6C for basically scrap price. The machine runs and drives but has some motor issues. After cleaning off a lot of mud and great build up, I finally found the serial number 74A1792. The issue I'm currently having is water leaks. Water is leaking out of 2 of the injector pre combustion chambers and also water is blowing through the turbo. Is this caused by the prechamber seals or could there be other issues further down? How do you think I should proceed? I've already ordered the special tool to remove the prechamber a, and have also ordered a parts and services manual, but have not received them yet. Here's a pic of the old girl.
The pre chambers crack at the radius above the threads. They can also crack further up from overheating.
You have a cracked head . Bob
That would also be my first guess on the water coming out the turbo. The leaks around the top of the pre-chambers are probably what caused the cracks. Leaked coolant and was ran with low coolant and overheated cracking the head. Depending on your plans for this machine and how it runs as it is right now you might be able to get by with a replacement head.
Well thanks for the replies even if it's not what I wanted to hear. I guess I'll be pulling the head and having a look. I'll report back what I find.
Drain the engine oil asap and refill with new oil. Antifreeze etches main and rod bearings. Do it even if your not planning on running it.
Will do, but I'm not seeing any telltale signs of water in the oil. It's black as midnight.
Well I started into getting the head off last night. I was only able to get the intake and turbo off in the amount of time I had. Looks like I'm going to need a new turbo now as well. Debating on whether or not I should continue or just cut my losses now?
It looks like something went out the exhaust into the turbo. Dropped valve or seat or piece of piston crown.
Decide what you are comfortable spending on this project. If it isn't much then cut your losses now
There were big chunks of what appears to be rust past the turbine. I'm wondering if the stack was left uncovered and water rusted the inside of the manifold and then took out the turbo on startup. I paid $3900 for the machine. Don't know what it would be worth of the motor was in better condition. Appears to have near new rails (berco), sprockets are decent, needs a few rollers. Haven't messed with the winch yet. Also the fan/water pump was locked up so that probably helped with overheating. Hour meter on the motor is showing 2900 so I'm guessing the motor had some work done at some point or the meter isn't working.
You can forget about that meter being close to right. You are only scratching the surface of what will be needed ide bet. I personally see this as a BIG dollars project
Yes! no telling when that meter worked last or how many have been on it since it left the factory!
The engine will be the cheapest and easiest part of that machine to repair but if the rest of it is in overall good shape, it could be made into a good-running machine. Depends how far you want to go with time and money
You'll know more when you get the head off and see if pistons & liners look ok. I was in your shoes a few years ago with my 10k D6c. As it ended up I've worked on every part of the machine except the torque converter.... some things more than once. You'll likely need a replacement head plus water pump and turbo at a minimum. Probably radiator work, maybe oil cooler. Did you run it enough to know if it shifts, brakes, and turns like it should? Oil pressure? Final drives leaking? Loose sprocket bearings?....(check for sprocket movement with long pry bar) Pic looks like it has plenty of engine leaks. To make it dependable there's 1000 things to check/fix. Not trying to discourage you, just the reality of old neglected equipment.
There have been dead axle problems with D6C. Very expensive to fix. Not sure how to check.
This is a direct drive unit and when I drove it off the trailer clutches and brakes worked. Never got it out of first gear to see how the rest of the transmission gears worked. Oil pressure was good, fuel pressure good. Left track was loose but it did take grease and tightened up but we'll see if it stays that way. Slowly working on getting the head off. Water pump is out, needs bearings and seals but looks like rebuild kits for the pump are pretty cheap. The radiator is holding water at least but I haven't run it long enough to see if it will hold pressure. This should be a fun project, hopefully it isn't too difficult. I'm not really well equipped to handle some of the heavy stuff so we'll see how it goes. I'll keep this thread updated as I progress and I appreciate everyone's help!
Been there too.... twice. First time it didn't stay and the dead axle would still rotate some so it got bored out and bushing put in. If you get it ready to do run, take the sprocket shield off and paint a stripe across the hubs and the inside end of the axle. That way you can tell if it's moving. If you have to do dead axle work, find a good independent shop. They'll be much cheaper than cat. You'll probably still have to have Cat come out and do the boring and make a bushing. They don't give out the info to make your own.
I finally had done time to pull the head and you guys were right. Found cracks at the number 4 & 5 prechamber threads. Is this repairable or is a new head in order? Liners and Pistons look ok, still see the cross hatches on the liners.
It is repairable, There are shops that do that kind of repair. I don't think the repair comes with a guarantee or warranty. The pre-chambers need to be tested for cracks as well.
You can buy recon loaded heads as well as aftermarket new loaded heads . Loaded heads have precups already installed. Check your local Cat dealer for prices and availably. You may want to at least pull the pistons on those two holes to check for broke rings. Bob
After all, you're into it this far
Diesel Cast Welding out of Blaine Minnesota. If I remember right, six month warranty.
Ok I've been searching around to figure out my best option for fixing or replacing the head. My parts book says my head is an 8M0694 and with some Google searching I see that 5S1884 cross references to the 8M0694 head. Can anyone verify that the 5S1884 head will work? The 5S1884 head seems to be more readily available and usually much lower priced.
Not 100% sure but looking at SIS I'm thinking the difference is that the 8M0694 has the pre-chambers and valves installed and the 5S1884 is more or less a bare head with only the valve seats installed. Maybe someone else can check and confirm that?
8M0690 is the head casting number 5S1884 is the head part number.
Or to put it slightly differently, 8M0690 is an absolutely bare cylinder head with nothing installed - not even freeze (core) plugs.. 8M0694 is an 8M0690 with all the plugs & covers, precombustion chambers, valve guides, and valve seats installed. (No valves, springs, retainers, etc) 5S1884 is an 8M0694 MINUS the precombustion chambers.
Thanks for the help everyone. Going further into my parts book, 5S1884 shows as the cylinder head assembly starting with serial number 74A2467. My serial number 74A1792 shows 8M694 as the service assembly It looks like the 5S1884 head doesn't have the decompression lever assembly and also has different part numbers for the chambers and seals. My machine is electric start and the decompression lever was not hooked up, maybe it was converted from pony start at some point?
Hi everyone, I have come across an eBay seller that has a head from a d333 engine. He says it is from a D6B naturally aspirated. Head is fully rebuilt. I am wondering if this head will work for me seeing as mine is a turbo application? The price is under $1k so it's worth seeing if it will work for my application.
what did you find out?
D6B 44A4628 to 44A12416 uses a 8M0694 service head.
I would also pull the radiator out and have it checked over or replaced with new. Mine was built up with iron deposits, wasn’t cooling engine Along with the water temperature gauge being defective!also have water pump checked over, mine was worn so wasn’t circulating water throughout the engine!FYI