How to remove stuck valve caps from a trumpet or cornet

If your valve caps are stuck, likely they have become cruddy and may need to be removed by a professional. Here are a few tips to try to remove them yourself.

Difficulty: Moderate

Instructions

Things You'll Need:

• Non-metal mallot/hammer
• Penetrating oil

1. If the caps are stuck and cannot be removed normally, begin by lightly tapping along the edge of the cap with a rawhide mallot (or other non-metal mallot). This should loosen the crud and allow the cap to turn. Do not hit the cap hard and be careful not to hit any tubing or the valve casing itself. If you have only one stuck cap, make sure you have all caps in place before tapping on the stuck cap. This will prevent accidentally damaging the other caps threads.

2. If caps still cannot be removed, use a penetrating oil and spray/drop it along the seam between the cap and the valve casing (can be purchased at auto parts stores). Allow to soak for 15 minutes. If they cannot be removed by hand, repeat tapping procedure.

3. If the cap(s) still cannot be removed, allow penetrating oil to soak in overnight. Try to remove by hand. Repeat tapping procedure. Try to remove by hand.

4. If at this point you still cannot remove the cap(s), you will need to bring the instrument to a professional repair technician.

Tips & Warnings

• You may apply light heat with a lighter to the caps after oiling and before tapping.
• NEVER use a pliers to remove a valve cap. This can and will cause extensive damage to the instrument.