Spent some more time playing around with the D4 yesterday and also reading through the manual.
First thing was change the oil in the pony motor.
One thing I'd wanted to do was check the valve clearances. When I picked up the thing it had a bit of a miss at idle, where every now and then it'd miss and then rev back up. It'd do this about every 5 seconds or so. Interestingly it's not doing that at all this season - so having fresh diesel with a bunch of Power Service Diesel Kleen in may have helped un-gum some stuff in the fuel controller. Still, I had the hood off the thing from messing with the pony motor and thought this was a good time to check it. Here's a video of me letting it warm up before checking the valves:
This dozer had smoked some, especially at idle, even though it ran well. And I figured who knows when the last time the valves were checked, may as well. Good thing I checked them! Clearances were supposed to be 0.010". A few valves were loose, but about half of them (more than half I think) had zero clearance at all! Not good and probably means those valves were actually being held open a hair. After doing the adjustment the idle smoke stopped and it definitely seemed to run a bit more evenly, although as a Cat, it still ran and sounded good. I love the sound of a proper old diesel.
In the video you'll note some smoke coming out around the exhaust manifold. There's a flange there that is on solidly however there's a gap in there and it seems that whatever gasket may have been there (if any) is missing and/or blown out. I figure the best way to handle this is probably going to be some exhaust seal putty to put on and just see if that can seal it up well enough. I've had good luck with that stuff before in the right scenario.
When warm the dozer seems to have around 20 psi of oil pressure, maybe a bit less. The manual says 30 psi is what you should have. Since who knows how old the oil is on there, I figure it's time to change it. Cat recommends 30 weight oil, but I figure I'll go with 40 weight to try to get that oil pressure up a bit. I haven't bothered to find/check the hobbs meter (who knows if it even works). This thing is 70 years old or more, very well could be the original engine - I think it's entitled to be a bit tired. But it still runs well and I'm not too worried about it.
Another thing I'm going to do is go through and lubricate all the lubrication points on the thing. There are a lot of them! Most take just motor oil, but I also need to get some grease on my grease gun and hit the zerk fittings. I will also check and maybe replace the oil in some of the other things, although for the non-engine components I'm less worried about the age so long as it seems to be in good condition and not filled with water.
Some may recall that last year I purchased and rebuilt the hydrualic hoses going to the ram. They seem to be functioning correctly, no leaks!
It really is a neat machine, and has tolerated sitting very well.
