The leaky green stuff is a broken Fuel Rod that powers the saucer. You will need a new one. (see related question)
The saucer Excalibur is crashed in the mud swamp to the right of the Mill.
The "broken pipe" refers to the damaged fuel cell in the saucer Excalibur, which is crashed in the mud swamp past the Mill. To reach the saucer, use the hovercraft. To fly the saucer, get a replacement green fuel cell. (see related questions)
Mordred's hoverboard uses manure, but the saucer needs a new power source. It has a broken Fuel Rod, and the only place to get one on Arturus is from the robot invader in the dungeon.
Write down 56 52
The crashed saucer Excalibur needs a replacement for the broken green Fuel Rod. You can get one from the robot invader in the dungeon. (see related questions)
When you get a new fuel rod, just place it in the spot on the saucer and it will lock in. (see related question)
The damaged saucer Excalibur has crashed in the mud swamp to the right of the Mill. You can reach it with the hovercraft (hover board) in the attic of the mill. (see related questions)
No oil on Astro Knights Island. The hovercraft runs on manure, and the crashed saucer Excalibur needs a replacement for its broken green fuel rod. (see the related question)
The fuel rod is broken on the saucer Excalibur, crashed in the mud swamp. You will need a new one, and someplace to fly the ship to. (see the related question)
x-56 y-52 it will get you to the moon. the moon is the only place you can go on the flying saucer
It is half-buried in the mud swamp right of the mill. (see related questions)
You must enter the Astrozone building and swap your saucer for a new ship, which you build on the Holopad.