bob, sorry for delay, just back from a 3 week trip.
The Black brass sleeve was from an IP housing from a bad pump that was not cleaned. I am not sure why the brass bore was black , not sure if dirty fuel
or brass wearing from diss similiar metal or both. .
Did not appear to be scale, it just looked like a blacking of the brass,
My housing was cleaned when I got to look at it, ( pictures ) I could
see the wear on the brass sleeve from the metal piston ring.
do not know if it was black prior to cleaning ( neglected to ask )
If I get over by the Diesel shop I will ask more questions...
The Black brass sleeve was from an IP housing from a bad pump that was not cleaned. I am not sure why the brass bore was black , not sure if dirty fuel
or brass wearing from diss similiar metal or both. .
Did not appear to be scale, it just looked like a blacking of the brass,
My housing was cleaned when I got to look at it, ( pictures ) I could
see the wear on the brass sleeve from the metal piston ring.
do not know if it was black prior to cleaning ( neglected to ask )
If I get over by the Diesel shop I will ask more questions...