Injector seals

[MikeT]

As previously stated, #2 injector had a hardened black glaze of deposits all around the top of the threaded hole (which chipped away fairly easily - cooked oil or diesel?). That injector proved to require a lot of force to unscrew until the very last thread. Looking in the threaded hole, there is the same black deposits on the lower threads making it impossible to remove the copper washer and fire seal.

In fact, only two of the four copper washers came out - the rest are refusing to budge, even with a sharp lever behind them. Ditto for the fire seals beneath.

Is there a clever way to convince these stubborn parts they should come out?

[Peter.N.]

The 'residue' is carbon from the engine combustion, leaking up the side of the injector, probably because it wasn't seated properly.

[citronut]

or the injectors had been fitted without fire seals
regards malcolm