NPK GH10, Operator'S Manual

Page: 17 / 71

NPK
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LUBRICATION
CORRECT GREASE AND GREASE INTERVALS
Proper hammer maintenance requires a sufficient supply of the correct grease to the
tool (chisel). The tool must be pressed against a hard surface until it stops up inside the
hammer. This prevents grease from entering piston impact area and ensures proper
distribution of grease between the tool and tool bushings.
GREASE INTERVALS
If the hammer is not connected to an Autolube system, see page 18, the hammer must
be greased at regular intervals to get the best life from the tool and tool bushings.
There are two ways to determine grease intervals:
First , grease the hammer at the beginning of the job until grease comes out between
the tool and the lower tool bushing. Run the hammer until the shank of the tool starts to
look dry. This determines the time interval for the greasing of this particular hammer on
this particular job. Typically, this is 1 to 4 hours. Also, note the amount of grease
needed to re-grease the tool. This gives you the amount of grease and how often it
must be applied. An example would be that a particular hammer, on a particular job,
requires half a tube of grease every 3 hours. This would be the greasing schedule you
would set up. If this hammer was moved to another job, another grease schedule may
have to be determined.
Second , if you can’t control the grease schedule, such as rental units, then have the
operator grease the hammer once every hour of hammer operation. Again, grease the
hammer until grease comes out between the tool and tool bushing. This is usually more
often than required, but is far cheaper than replacing prematurely worn tools and tool
bushings.
CORRECT GREASE
The type of grease used is very important. NPK recommends a lithium soap base EP
(Extreme Pressure) NLGI #2 Grease, with Moly (Molybdenum Disulfide) or other
surface protecting additives. A high drop point 500° F (260° C) grease is desirable.
On the following page is a list of commonly available greases, by manufacturer and
brand name that meet NPK’s recommendations. NPK does not endorse any one brand
as being superior to another. If you or your customers use a brand not listed, please
call the NPK Service Department at 800-225-4379.