Many peole don't know mych about rotary valves, but with just a little bit of care they can work like magic.
The following only refers to traditional, balanced and possibly the Lindberg valve. But definitely not the Haggman or Thayer.
How to clean and oil rotary valves.
How to take apart a valve
How to put a valve back together
How to break in new valves.
How to get your valves as quiet as possible.
How to Clean and Oil Your ValvesThe first thing you need to know how to do is take apart your valve. You will need a flat head screwdriver and a soft mallet.How to break in new valves
- First you have to take the linkage off the rotating pin. If you can, just unscrew the big screw in the middle of the valve. You might have to take another screw out first to let this one come out. When it comes out, be careful becuase the spring will want to pull the linkage away and this could cause some damage.
- After you get the screws out you need to get the piece off that connects the pin and the linkage. You might be able to pull it off with your fingers, but I usually have to gently pry it off with a knife or screwdriver. Be careful you don't scratch it up.
- After you get that piece off turn the horn over, and remove the valve cap. It should just screw off. You should look carefully at the plate before you take it off. You should see a little cut into the plate and casing. Remember this, because that's where it should go back.
- This is the dangerous part. You have to press on the pin and force the whole valve out of the casing. I saw the guys at D.C. Slide Repair using a rawhide mallet. You have to be careful that you don't use anything that will disfigure the end of the pin or cause stress to the rest of the horn. What I usually do is put the pin on the corner of a wooden table, and gently lean on it until it pops out.
- Now you've got your valve apart. On a normal valve, you should have the inside rotor, and a protective plate. Now you need to clean it. If there is no corrosion then you can just rinse it off under water, and get all of the old oil off of the rotary and the casing. If there is corrosion, you should be able to scrape it off with something, but be careful not to scratch the valve.
I like to use Al Cass oil on my rotors. Sometimes I use something calles Zaja oil, which is scented, just to make my horn smell nice, but I don't like to use it a lot because the oil is colored, and I think it might stain it. The oil should be applied liberally. There are really only two contacts, one on each pin. You should oil those but do the whole outside of the rotor too, just to make sure it spins really smooth.
Now you get to put it back together.
- With lots of oil on it, put the end with the hole for the screw into the casing. Make sure that it spins well by turning it with your fingers.
- You must be careful putting the plate back on. It has to go in straight or you could bend it, or just really mess it up. Gently place it on top and evenly press it into place. Remember to check the hash marks. Usually it's hash for F attatchments and two for second valves. Air bubbles may come through the hole, but that's ok. You should make sure that the plate is even with the pin, and also look to see that it's seated all the way down to the casing.
- When you put the piece back on the pin, make sure that it is going on in the right direction. Yamaha trombones have an odd shaped pin, so you can only put in on one way, but I don't think Bach horns do. When you put it on, flip the horn over, and look at a tiny line on the pin. When you turn it, it should line up with the tiny lines on the plate. If it doesn't, take it off, and turn the piece around.
- Instead of taking the whole thing apart, you can try just putting a few drops on the pin under the valve cap.
- The last step is to put the cap back on. Sometimes I have difficulty getting this on right. So what I like to do is place it on, then spin it backwards until I hear it fall on the threads. Then you know it will screw on correctly.The only thing about new valves is that manufacturers oil them with a very heavy oil that will stay on the rotor for a while. When you get the horn, you should oil it about once a week for a couple of months, and then monthly, and then whenever you think it needs it.How to get your valves as quiet as possibleThere are lots of reasons that a valve gets loud. With Bach horns, it is usually the linkage, and the only way to fix it is to get a new linkage. Todd Clontz makes the best ones, and they are available at Hickey's.Please E-mail Me with any questions, comments or tips you would like to share.
Another common reason that valves will be loud is that the stop plate comes a little bit loose. This can be tightened up with a phillips head screwdriver.
My last trick in getting them quiet is using heavy oil. This is what is commonly marketed as rotary valve oil. I put a drop or two on every moving part that is outside the rotor and this usually fixes the problem.