I also should’ve mentioned this! I’ve had to do the same with my horn valve. What type of horn valve are you using?

@@sepa2401 GG train horn air valve floor mount and stand 4" tall

@@vidrioandsonstrucking2422 I don’t have that type of valve, but I’ll try my best to help. Your leak could be occurring from loose connections on your hose. A good way to check is with soapy water (Simply spray it on the valve and hose connections and check for spots that are bubbling). You should then clean cut the hose and ensure a secure connection between the hose and the brass fitting. If it’s the valve itself however, you would want to clean the inside of the valve as best as you can, and then ensure the nut on the valve handle it tight enough that it doesn’t leak air. Remember to always use teflon tape on all NPT pipe connections as well.

I can help you! Feel free to reach out via my email. Make sure to send pictures and send a description of the problem as there are many points of failure.

I've had these horns for over a year and they've worked mostly fine without issue. While mine is mounted on a bicycle trailer (which is sheltered from the elements), yours was under a truck where it's exposed to the elements. Even if your horns were not dirty on the inside, they could've still had issues due to moisture inside your air lines. Another thing is the volume and PSI you ran them at. If you ran them with lines larger than the horn could handle, that could've blown out the diaphragms. If you ran them over the rated 150 PSI, those could've also blown out the diaphragms. I would say however that you horn could've been defective from the start due to poor manufacturing. If the seat where the diaphragm sits on has chips, It's no good. If the inside ring on the backcap has issues, it also would have trouble sounding.

May I ask what problem you experienced with the horn? Did one or two trumpets sound, or was there no sound besides air blowing through the lines?

Again,they were NOT mounted under the truck. They were mounted behind the cab halfway up. So no elements had an effect on them. I keep my truck clean! Show time if you know what that is.

Obviously you don't much about classy trucks. I have a Bendix factory built and installed air dryer system on this truck. I'm no rookie here. Been doing this for 43 years. Have had several types if horns on my trucks. There is no debris, no moisture,no dirt ,they are spot less inside and out. The stainless steel diaphragms are just not as pliable as the plastic junk they had inside. I've tried decreasing the air pressure, increasing it,etc. Mine are straight lined off a half inch air line thru a manual hand valve. Which is also United pacific approved.

@@sepa2401 again semi truck. 128 lbs MAXIMUM ON AIR PRESSURE. I'm thinking flexibility, and diaphragm thickness.