i have a basic harbor freight demo hammer that uses SDS MAX bits. its not clear how to keep it greased. there is a plasict cover on top (see pic) that has a huge chamber beneath. its not clear how much or what type of grease you are supposed to put in there.
also, is the idea that this grease is supposed to heat up and flow down the shaft there the bit attaches to keep it lubricated . i.e. that you do NOT have to also grease the bit itself?
Having the same hammer and the same question: the manual doesn't say anything. Reddit says to use a decent all-purpose or moly grease.
Since I use my hammer very rarely since "the one big project" (breaking up the pad and a couple of steps that had been part of a garden shed on a hill) I decided to use the same wheel bearing grease I use on my trailer since I have a big tub of it.
I used up the tub the other day and decided to look up whether there is an easily found product (there is, Home Depot sells "Makita Hammer Grease" and there are a few others). They're all special order for me, so my seldom-used SDS hammer is still sharing axle grease with my trailer.
