All instruments become dirty inside over time and use. Flushing is a procedure to remove deposits from within brass tubing. If done regularly, it can be one of the most beneficial maintenance procedures you can do to prolong your instrument's life. Instrument repair shops will do a chemical flush, which is like this procedure, only with the use of an acid. This can be expensive, and is unnecessary if you give your instrument a bath at least twice yearly. Please review the parts of your instrument before going ahead, as the instructions use specific terminology. French Horns, Euphoniums, and Tubas are cleaned by HMS. Do not do this at home.

Make sure you have the following items before beginning: (a) Polishing Cloth (b) Shop Rag (c) Valve/Slide Oil (d) Slide Grease (e) Mouthpiece Brush (f) Snake Brush (g) Valve Brush - trumpet only (h) Cloth Towels - not shown
1.
Disassemble your instrument - Pull all slides, remove valves, remove valve cap bottoms. Trumpet piston valves must be set aside and cleaned by hand. Do not disassemble trumpet pistons.
 2.
Fill a bathtub with lukewarm water. The water does not need to be deep, just enough to cover your instrument body. Place the disassembled parts in the water on towels or rags so the instrument does not get scratched.
 3.
Allow your instrument to soak for 20-30 minutes. Trumpet valves should be cleaned by hand at this time. Use the valve or mouthpiece brush with a small amount of water. Valves should be inspected for corrosion or damage. Once clean, set them aside. Remember: the valve number is stamped on the brass near the spring. Valves must be put back in their valve casings in order.
 4.
Using the snake brush and valve brush, scrub the inside of all tubing. Run water through tubing and repeat until it comes out clean.
 5.
6. Apply grease to slides and reassemble them into the body of the instrument. Trumpets apply oil to piston valves and reassemble them in order.

7. Polish your instrument with the polishing cloth once it is dry. This will remove any water stains you might have missed.

8. Play test your instrument and empty any excess water with the water keys. Trumpets will not be playable if the valves were reassembled in the wrong order, or not aligned in the valve casings.