Horn sounds wierd

My horn has been in for over 1/2 year now. It has been sounding wierd for the last 3 months or so, more high pitched. I thought it might be due to the humidity and water accumulation in the tank. I’ve drained the tank and slowly bled the water as it presses up. Still the same thing. Any ideas???

Are they Shockers? And are they squeaking or generally higher pitched?
Here is a current thread:
http://www.trainhornforums.com/showthread.php?t=5266

Awesome! I didn’t think about it, but it does change pitch when the pressure depletes. That’s why I thought it was clearing water 1st. I’ll call them. Thanks!!!

Welcome to the forum. Hornblasters has great customer service!