Dozer D6H LGP SERIES 2

Hi,

Base on these issues you listed above, I think you should replace new seal for all oil valves only. And out of that you also need check condition of valves that mean inlet - outlet line.

regards,

Yes you set the #1 valves when # 5 is on the overlap with this firing order. Next will be # 4 when #3 is on the overlap etc. If your not sure which valve is exhaust or intake just look over the top of the engine to see which valve lines up with the exhaust manifold tubes or ports. Exhaust valves are always the looser setting. When you remove the valve springs make sure that the cylinder that you are working on is at top dead center so that the valve doesn't drop into the cylinder when you remove the valve spring keepers. The valve seals are probably the cause of the oil leak but it may also be piston rings. If the engine hasn't been operating at proper temperature due to a faulty thermostat or being lightly loaded that will cause oiling. Another thing that causes this can be seized piston oil control rings. Sometimes you can cure that with an oil additive that will act as a detergent and clean the gunk from them. First I would try the valve seals as you have said. You'll know when you remove them because they'll be quite hard.

If you can't obtain a manual or find a sticker that states valve clearances, run the engine with the valve cover off and use a long screwdriver to listen to each valve. Make notes of each valve and if it is quiet or clacking, once the engine has warmed up enough. Turn off the engine and measure all the clearances. Valve clearances change due to valve seat wear, valve stem end wear and "mushrooming", rocker arm end and pivot wear. You can detect valve stem "mushrooming" by using a pointy tool and running it up the side of the exposed valve stem. Any "lip" is "mushrooming". Be aware if the valve stem has a hardened cap. Rocker arm end wear, both valve end and push-rod end are difficult to detect when assembled, even when disassembled but if the pivot is a rocker shaft, turn the engine so the rocker is not loaded and try to wiggle it on the shaft. Any unreasonable movement is too much. Look at all the data and eliminate all valves with observed wear problems. Look at all the rest, separating intake and exhaust, and see if there is a trend relative to clearances. I would set the clearances there to start. Once warmed up, one at a time, loosen each until clacking starts then tighten, counting the turns, until the engine skips. Then loosen 1/3 of the counted turns. It may not be exactly to spec, but without specs to go by, that will get you safely running. Check all the clearances and record them. After a couple hours of running, check them again, HOT, to see if anything changed.

Have you tried a google search for info on the engine?

At any rate, apply air pressure to the cylinder that you are working on, and rotate engine till the air flow stops.This will hold your valve in position to allow the seal replacement without the valve dropping down into the cylinder.