Here's Dan removing the valve cover. We took out a few injector nozzles first to look at them. Then I believe there are five bolts on top of the valve cover. There's a gasket there that has to be replaced.
Here's what was under the valve cover.
Close up of the gook. It's a thick layer of condensation of coolant and oil. Not stuck on, just thick and lumpy lookin'.
This is a pic with everything still attached but the valve cover. The rods are still in, the rocker arms are still all together. The big wide rusty thing on the side is the exhaust manifold. The round part coming off the side of the exhaust manifold is the turbo, and the big white pipe is the exhaust pipe.
In this pic the exhaust manifold and turbo have been taken out. The rods and rocker arms have also been removed. There are 26 bolts holding the head in place, and one row of them holds in place the rocker arm assembly. The bolts are arranged in circles around the valve springs, and to reassemble you're supposed to slowly tighten them in an X-pattern from the middle to the outside. The exhaust manifold (removed from this picture, was on the right) and the intake manifold (green thing on the left) are each held in by six bolts on the top and six bolts on the bottom feeding into the head. The ones on the bottom are a PITA to get out.
Once all of that is removed, we had to detach a few hoses and a pipe to make room for the head to come out. For some reason the school district plumbed a garden spigot into the coolant system, maybe to turn the heat on/off in the cab? When we removed the exhaust manifold we also had to take the thermometer out of it. The head sits flat on the engine block, but there is one 1/2" dowel sticking up to help you align it later. Careful not to drag it on anythig, it took two people to lift it out. Make sure not to set it flat on the ground if the injector nozzles are still in it. In the pic you can see the head gasket moving out of position. It will also have to be replaced.
To get the pistons out one person went under and turned the crankshaft so that the bolts on the bottom of the piston where the rod bearings are was accessible with a socket. Unbolt piston, then chrank the shaft until the piston is at the top of the cylinder, where it can then be removed. You can tap on the bottom of the piston rod carefully with a soft stick and hammer to help push it up and out. Careful not to damage the cylinder as it comes out and not to damage the piston after it's out.
The do the same sort of thing to get the cylinder out. My dad made a tool out of a rod and nut and base that lets you pull the cylinder up by turning the nut.
Here's the piston with the rod bearing. Looks new.
Here's the engine block sans pistons and cylinders.
Hone marks on the insides of the cylinders make it look new, too.
But the O-rings are terrible. The outsides of the cylinders have minor corrosion, and one has a very small area of shallow pits. Nothing that would cause a leak for a long time.
No wonder we had a leak! Every single O-ring is bad on all of them!
The engine is outside the bus basically. Scary.
Not sure if video will work or not, but this proves I can do it!