If you have a problem with your valves. Please try another oil. I have found that if you clean the old oil out with hot soapy water and a valve brush. You can switch to another oil. Some oils will leave a build up on your valve casing that can cause your valves to stick once the become warm and moist from playing. I like the new Yamaha synthetic for new horns and the Hetman for older valves. Both come in different weights. Check us out at www.hoggtownemusic.com