The bores are 4" on the tractor, but all the cylinders are toast sadly, I've never seen rust damage like this on a old Cat before, plus one cylinder had water in it, and I had to press the piston out, that took all of 20 tons to get it moving, even though I'd lit it up twice with diesel and oil to get it all nice and hot. Luckily the piston will clean up, though all the rings are very worn and show at least 1/4" end gap, you will see that in the photo.
All the cast water manifolds on this tractor are badly cracked, except the bottom pipe that runs to the 4 cylinders, that is perfect, the bottom radiator tank is not cracked, but the top tank of the radiator has a small crack in one corner. That bit of water pipe elbow welded to the drop tube is an interesting modification, I know that this tractor was still being worked hard up till 1972, when it was sold as a parts machine, so I assume the broken drop tube issue was well known to everyone, and this one was modified.
This tractor had been reconditioned at least once, the undercarriage, like grousers, sprockets, front idlers and bottom rollers plus steering clutch packs look almost new, yet both both brake pedals show lots of wear, the curved water pipes have both been replaced with farmer "upgraded" water pipes with bits of fencing wire, so the tractor was used long enough to rot out the originals, yet deserve to get new ones fitted.
It is always interesting to pull a old Cat apart, you can see where Farmer Fred had worked on them, and where they are untouched, things like dodgy gaskets, and bent nails used in conrods, instead of split pins, though it always impresses me how those old Cat bolt heads are usually still in good condition, and will unscrew without breaking, even after 90 to 100 years.
