D4 7u cylinder wall pits

David,

Have you tried loosening the piston by using a sturdy hardwood battern and large (4 lb+) lump hammer from the underside of the engine block to knock it upwards? It did the trick for me once I had pre-soaked the piston \ liner in diesel.

Presumably you may be apply the same technique to remove the liner, but it would probably be better to use a jack to apply greater pressure (i haven't tried it before).

Can you post any pictures of the pitted liner on the BB?

All the 4 1/2 bore pistons \ liners from the D315 engine used in the U series tractors (6U & 7U) are interchangeable, as can the 4 1/2 bore pistons & liners from the 6 cylinder D318 engine in the 8U & 9U tractors.

KB, you can get new liners from Regal Corp for $24 ea.. see the parts sources post..

If you turn the engine over with hand crank the piston will either go past rust or shove the liner out then after piston and liner are out press piston out the bottom

Willie,

That's such a simple idea - top tip!