REPLACING HEAD GASKET
I was hauling a tractor for the neighbor this weekend and when we stopped to unload the front differential was wet with coolant, again. The truck has never overheated, its always gets adequate warm up and cool down time. The last time a few weeks ago it was the radiator, got it fixed and thought all was good again. Well after limping it home and looking at it, it looked to be the thermostat housing. Replaced the thermostat, and resealed the housing and then pressurized the system to check for other leaks. Well the leak is really coming out between the head and the block right under the stat housing.
Is this happening often with other trucks? Mine has 195,000 miles on it. I don't think it has anything to do with the fuel settings or other mods, not losing power, no oil in the coolant, no coolant in the oil, just an external leak of coolant.
So after I accumulate all the necessary gaskets, I will embark on pulling the head. Anything I need to address while I am in there other than the normal head gasket replacement? I don't want to spend alot of money, but I want to fix it right!
MMiller, Stockton, IA
Unfortunately, this happens a lot. I will try to lay down some good tips. First, go to Cummins and get your parts, and the head gasket kit. It comes with tons of gaskets and about everything you will need to do the job. Your gasket kit will come with a head bolt grading gauge, some don't worry about it all that much, but I would stress using it. I really hate doing jobs like this more then once when avoidable. Another very, very, key point here that is easy to get confused by: You have three sizes of head bolts. I stress this one because I have seen the aftermath of not following the torque right. Your short bolts are the ones that are located around the exhaust manifold, your long bolts are the ones that secure your rocker assemblies. The medium bolts are all of the ones in between. Follow the torque, and understand that only the six long bolts go to the highest torque then everything goes an additional 90 degrees. The easy way to do the job is to leave as much as possible attached. For instance, remove your exhaust manifold, leaving the turbo attached to the drain line and to the exhaust pipe, leave the injectors in (if you have a lift of some sort), return line on, remove only the bolts that secure the injection lines to the intake plate, don't remove the grid heater wires, remove the intake bolts and pull the grid heaters out of the way. I know it sounds like a gross mess, and it might look that way while doing it, but it will speed up the job, and eliminate time wasting on things that were not problems before you started. By the way, buy a good easy out/extractor set before doing this job, and soak your exhaust bolts with good stuff for as long as possible before going to town. If you manage to not break off an exhaust bolt, you should get a lucky star. A good way of attempting this is to use a 3/8" impact gun and worry them out. Tricky, yes, but it does work in some cases. Try to tighten the bolt then back it off and vice versa until it starts to come out. It still might break. Clean all parts good, use a light form of scotch-brite (Cummins may have this) to clean the head and block surface, and you should be just fine. Set the engine on TDC the head off.
Tools:
Strong friends or a chain lift of some sort. (If you have this you can take the head off with the turbo and exhaust manifold attached
Good torque wrenches to get from 10-98 ft/lbs
3/8" impact: just makes it nice
1/2" impact: for the extra 90 degrees on the head bolts
Sockets.
A key tool that might cost a lot in the big picture, but will make you real happy with the injector lines is made by snap-on. It is an injector line socket that is 3/8" drive and is either 11/16" or 17mm in size to get the lines on the pump loose. Oh yeah, take them off as two assemblies.
Wrenches.
You might need an injector puller/brush for cleaning if you go that route.
Good supply of penetrating oil.
Small torch for stubborn things.
Patience and organization.
If you need any more help, I'll try my best.
R. E. Miller, Columbia, MD
Only thing I would add is loosen off valve lash before removing towers and back off smaller of the tower bolts first, then larger ones when removing. Then reverse for install. nascar mark, Langley, BC, Canada
Replace any rusted bolts, especially those rusted in the fillet area under the head of the bolt. Mark the heads of the bolt with a paint pen before the 90 degree final turn, then when all the paint marks are pointed the same way, you know they are torqued. Check for cracks around the injector bores and between the valve seats. A lot of people get worried about the surface condition and you will likely see some erosion where the fire ring seals around the cylinder. My theory is you are pulling the head for a leak close to the thermostat, not trying to make a new engine, if it ran fine before it will probably run fine again. It's important that the surface is clean and dry on assembly, if you don't have a good contact cleaner available, steal the rubbing alcohol out of the medicine chest and use it.
Ajohnson, Ranier, OR
Great posting I will save and hope I don't need it. I have just one thing to add. Be extremely careful if you use scotch-brite to clean the block surface. About four years ago when my son worked for a Goodyear store, Goodyear issued a national policy that said "do not use scotch-brite" when cleaning anything that was not put in a wash tank afterward. The minute particles can easily get flushed into the oil system, they don't filter out well, and Goodyear had to buy too many engines that self destructed from these particles. Just a heads up. I stopped using scotch-brite after he told me this.
JLEONARD, Torrington, CT
This is a good point, every head gasket job gets an oil change at the end of it. Also, when you go to Cummins, ask for a gallon of Zvoc cleaner. It really works great, no residue, very powerful, but not too much. Another point to remember when doing this job which goes along with cleaning: use a brake cleaner, a rag, and your air hose set to stun to blow out all of the head bolt holes, very important for good torque readings. You can also use the Zvoc to "wash" down the block after using the scotch-brite.
R. E. Miller
Special thanks to everyone that replied to my post. Yesterday morning I started on the project at 7:30 am. By 9:30 am it was completely disassembled. All the manifold bolts, exhaust clamp, the turbo mounting studs all came loose, without breakage. Cleaned everything up, everything looked good and started reassembling. By about 7:30 pm it was back up and running, leak free, except for the fuel lines at the filter base, which there were no new seals in the upper end kit. I have to get those this week to fix that small leak. Left it in the shop overnight and today changed the oil, filled up the coolant the rest of the way, washed it and brought it home. This weekend will recheck the valve lash.
A couple of things I would do different.
Remove the injectors, Its not that hard to do and it is far more time consuming to be extremely careful handing and cleaning the head with them in. I got into two of them with the buffing wheel, they will work for now but will get replaced later, maybe time for some performance ones?
When installing the push tubes, it is very easy to have them miss the lifters, seems to be harder to feel them than the cats I am used to. Make sure they go into the lifters correctly before installing the rockers. I had to redo three of them.
The one thing I forgot to do. While the head was off I was going to remove the low idle stop lock nut and install it on the other end for easier adjustment, but I got all worked up getting it together. So I guess for now it will still idle a little high, oh well its easier to four wheel it that way anyways.
Thank again for all the responses to the head gasket, it is very simple, just kind of tedious.
MMiller
Attention: TDR Forum Junkies 
Made no noise, just leaking externally. Hate to do jobs twice
