How to Reassemble a French Horn Valve

The French horn has three rotary valves that generally do not need to be taken apart. They can be cleaned quite easily by removing the rotary valve cover, bushing out the inside with a cotton swab and oiling the internal moving rotors. However, there are times when it becomes necessary to take a rotor apart and reassemble it when the valves become overcome with dirt and debris. Replacing French horn valves is less difficult work than removing them, but it is still a delicate process that requires care.

Step 1

Slide the rotor back into the valve casing, so that the screw on the bottom of the rotor peaks through the hole in the bottom of the valve casing. You may need to use a rubber hammer to hammer the valve back in place. This is a delicate process. Take your time and use light strokes until the valve is back in place.

Step 2

Align the valve by turning it until the notches on the side of the valve line up with the alignment indicator inside the valve. The valve will drop into place when the alignment is correct.

Step 3

Screw the bottom nut back on about three turns clockwise, until the nut is flush with the bottom of the valve casing. You should not need tools for this process.

Step 4

Replace the top valve cover and turn in clockwise until the valve cap fits securely.

Warnings

Very seriously consider taking the horn to a repair shop. This is a delicate procedure, and if you are not experienced working on musical instruments, you can cause more damage than the cost of having your valves professionally reinstalled. The French horn is not like other brass instruments and has several small parts that must be handled with care.