MAINTAINING THE BTFP12570 SERIES TOOLS
TO REPLACE PISTON:
a. Insert the flats on the lower end of the driver piston stem carefully into the end of piston and plunger
wrench, BC1009.
b. Using another special wrench, BC1009, or another wrench of the proper size, unscrew the plunger from
the upper end of the stem. After this is done, it will be possible to lift the poppet off the stem.
c. Place the special wrench, BC1009, down over the piston stem onto the driver piston, locking the piston
ears in the slots in the wrench. Unscrew the piston from the stem.
TO REPLACE DRIVER:
a. It is not necessary to disassemble the piston-poppet-driver assembly to replace the driver. Pull the
poppet up on the driver piston stem as far as it will go.
b. Insert special wrench, BC1009, over the driver piston, locking the piston ears in the slots in the wrench.
Unscrew the piston from threaded portion of the stem.
c. To remove the driver blade from the piston stem, push the driver blade pin out of the stem. This will
release the blade.
d. Insert new driver blade into the slot in the end of the driver piston stem and assemble the driver blade
pin. Test the side play in the driver blade by grasping the driver piston stem in one hand and the blade
in the other and moving the blade sideways in alignment with the slot in the stem. There should be a
small amount of side play in the blade. This is necessary to take care of any slight misalignment between
the blade and guide in the nose. If there is no side play, the blade should be removed and the top (pin
end) just barely dressed off with a stone. It is not necessary to do more than smooth off the top to get
the necessary side play. Do not grind. Reinsert the blade and pin in the stem and test for side play once
more. Repeat as necessary to get this small amount of side play. Carefully examine the large threaded
portion of the piston stem. A nylon lock can be seen imbedded in a recessed hole in the stem. It is very
important that this nylon lock can be replaced when its locking efficiency has been reduced through
several disassemblies of the piston. It is necessary to use the sharp point of a knife, or some such
instrument, to remove this nylon lock. Insert a new one by setting it into the recessed hole in the stem,
and tapping it gently until firmly seated. Reverse these instructions to reassemble.
e. Assemble plunger flush with end of piston stem.
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