Secondary oil change instructions

INSTRUCTIONS FOR CHANGING THE OIL IN ROTORWAY SECONDARY DRIVES

 (This applies only to secondaries modified to be able to do so.)

 Using a 1/8” hex driver, remove the 1/4NF x 1/2” long plug from the rim of the alternator / fan drive pulley.

 With a 1/4” wrench, loosen the bleeder valve screw located directly below the plug in the alternator / fan drive pulley, at the bottom edge of the pulley hub. (Be prepared with a rag to catch the oil which will start draining out of the bleeder valve.) If you have a device which can generate a vacuum, such as an automotive brake bleeding tool, you can suck the dirty oil out faster, otherwise, the oil will gradually drain out. When no more oil comes out, you are ready to pump in the fresh oil.

  Connect a length of 3/16” ID (4 to 5MM) X 3/8” to 1/2” (10 to 12 MM) long hose (I prefer clear hose for this step) over the nipple of the bleeder valve. (Make sure that the box end of a 1/4” wrench is fitted over the hex of the bleeder valve, and that the valve is open about ¼ to ½ turn.) Stuff a rag under the port in the alternator drive pulley,

 Insert the out let of a pump type oil can that is filled with MERCON / DEXRON ATF for use in GM vehicles made before 2005 into the other end of the short piece of hose and start pumping the oil in until it comes out of the port in the alternator pulley. Tighten the bleeder valve, pull the hose off and install the plug in the alternator drive pulley. Wipe up any oil that may have spilled. Using an aerosol can filled with degreasing solvent and a fine discharge tube, insert the tube into the hole in the end of the bleeder valve. Place a rag around the end of the bleeder valve and give a brief squirt of solvent to remove the bit of ATF that is in the bleeder valve. (This is to prevent the oil being flung out and contaminating anything.)

 The secondary typically takes about 40 CC of oil to fill in a new installation, and about 30 CC when changing the oil.

 Change the oil in the secondary every 50 hours or so, depending on how much auto rotating the helicopter does.

 If you have any questions, please feel free to call Peter Kooiman at pjkooiman@gmail.com.