Posted by Jay Bertolet on July 06, 2000 at 08:16:12:
In Reply to: A beginner's question about rotary valve posted by Ted on July 06, 2000 at 00:10:37:
The easiest way to oil the valves of a rotary horn is to put the oil into the valves through the leadpipe. This will get the oil to all of the valves in one shot. Also, you can help the longevity of the horn by doing one more step. Before you oil the valves this way, take a snake and clean out the leadpipe. Without taking apart the valves, the best way to do this is to swab out the leadpipe using the snake and then running warm water through the leadpipe to rinse it out. This step eliminates washing any gunk from the leadpipe into your valves when you put in the oil. It also allows the oil, when you pour it into the leadpipe, to form a barrier on the inside of the leadpipe that helps prevent corrosion. Just be careful and thorough when cleaning the leadpipe. If you aren't, you can trap any debris in the leadpipe with the oil and this will actually speed up the corrosion process.
When you pour the oil into the leadpipe, hold the tuba in playing position and then tilt the horn slightly forward and to your right (as you're looking at the tuba while holding it). This will position the bend of the leadpipe that goes around the bell to make a little reservoir that will hold the oil you pour into the leadpipe. After you add the oil, put the container down, without moving the tuba, and then put your hands on the valves in playing position. Then gradually tilt the horn back to playing position while wiggling all the valves to get the oil fully into them. You may want to rest the horn on its side on your leg and tilt the horn back and forth before dumping the oil to get it to go through the valves several times for the fullest coverage.
You may also want to oil the top and bottom bearings of the valves. This is a little more tricky but you should be able to do it if you're careful. Oiling the top bearing of the valves is easy. Look where the linkage meets the valve and you should see a post that goes into the valve casing. Put the oil where this posts enters the casing and wiggle the valve. Oiling the bottom bearing is a little more tricky. Look at the back of the valves for the screw-on cap that covers each valve. One at a time, take a cap off to reveal the bottom bearing and valve plate. While holding the tuba face down, put a couple drops of oil on the very top of the post that is sticking up in the middle of the valve plate. If you're balancing the tuba correctly, this should make a little "dome" of oil that remains on the bearing. Then, carefully screw the valve cap back on, being careful not to disturb the "dome".
My experience is that you should only have to do this once for the summer. You may want to add oil through the leadpipe a couple more times during the summer but the bearings should be fine with this once over completed. Oiling the valves in this way will extend the life of the tuba and make the valve action faster. If it doesn't, you may need to seek a qualified repairman for further assistance. Good luck!