JCB hammer drill, massive spark?

[TheYardBloke1]

Hi all, i've recently been given the task of emptying the tool shed at work and have repaired a few power tools.
I've got to this JCB HD-101 DF hammer drill and it has a huge spark when running it.
I first ran it in a dim room and it illuminated the room (that's how big the spark is).
I took it apart and cleaned it out as it was initially covered in contact adhesive, i looked around the motor section and it seems fine?

Any ideas what could be causing it? and an tips on repair would be greatly recieved.

Thanks

 

[big-all]

heeelllooo and welcome TheYardBloke1

if the brushes are not too badly worn clean the commutator with non abrasive cleaner like duraglit o
brasso or silver polish
and rub the brushes to de-glaze the surface with a very fine file sand or emery paper

 

[joe-90]

Sounds like the windings to me. Dump it.

 

[big-all]

if the shed is cold and damp the brushes can glaze over after a while so worth a try

 

[Burnerman]

If its sparking like an arc welder, I guess the armature windings are bidding a bright farewell......Usually there is a dramatic reduction in power if this is the case, and a burning smell.
Nothing to stop you experimenting though!
John

 

[TheYardBloke1]

If its sparking like an arc welder, I guess the armature windings are bidding a bright farewell......Usually there is a dramatic reduction in power if this is the case, and a burning smell.
Nothing to stop you experimenting though!
John

This is a very good description of what is going on!

Brushes have been cleaned but still no success...so i suppose it's for the graveyard