Colchester oil leak

[voipio]

The condition of item #34 in the exploded diagram, "Front bearing cover gasket" would be telling. That, and the condition of the surfaces it mates up against. I would bet on the gasket being split, or damaged. The chuck would need to come off. It should also give you a chance to check the bearing/spindle seals.

There does seem to have been some trauma behind the chuck, and is it red Hermetite that I can see? Possibly a bit of a bodge.

 

[fizzy]

Free manuals to download here.
Remember all the older Colchester roundheads will be the same. The pics I posted were of the Triumph. Also Clausing are the same.

Colchester Lathe Co., Ltd. - Publication Reprints | VintageMachinery.org

 

[minimutly]

From the drawing I would say @bR39Da s right, no seal as such. But the picture does show some red goo and those socket screws look chewed up to me - looks like some history there you weren't told about?
Ultimately if the gasket is boogard you will need to make a new one, which means shaft out, clean, reset preload and rebuild. That should keep you busy for a day at least - let us know how you get on, with pics?
Just looked at the drawing - the shaft needs to be released from the back - so the bearing retaining collar, bearing etc, then the front bearing preload collar needs to be unscrewed, and the shaft will slide out. Remember the grub screws..
If you could get a gasket, and you really don't want to remove the shaft you could cut the gasket and fit it with some sealant at the cut at the top. You'd need room to clean up all the sh1t under the collar though, and I'm not sure youd get it?

 

[Agroshield]

...you could cut the gasket and fit it with some sealant at the cut at the top.

If you cut the joint in the gasket like a jigsaw puzzle, coupled with the sealant, it makes a much more tortuous path for the oil to escape

 

[paradipiro]

Check the returning oil passage (at the bottom of the labirith ring housing). I would assume, that the oil level is abnormally high, othervise the oil would just dripping, not pouring.