I just had a set of Nathan K5LA’s installed on my truck. I had the horns already brand new and had them powder coated. After Installed with 2 5 gallon tanks, 2 440 compressors and at a pressure of 150 psi. Only one bell is actually firing(the 3 bell), which sounds terrible and sick. The other 4 bells aren’t even vibrating or moving air through them. These horns sat for a year and a half before actual install. Does anyone have a clue on where to start? Should I take them off and look into the diaphragms? It was brand new when purchased, immediately powdercoated and then sat. Any and all ideas welcome. I checked the airline and its not kinked, the regulator is reading 150 psi, no air leaks I can hear. I’m stumped, pics to follow tomorrow of my install… Thanks in advance for all your help!!
Are you sure the valve is installed the correct direction and operating properly?
to eliminate some variables i would bypass the solenoid. like start by unbolting the horn rigging it up were it just hose and a ball valve. my best guess is your solenoid may be installed wrong or wired bad…
Also I forgot to note, there is a quick disconnect between the solenoid and horns manifold. I disconnected it and manually hooked up the shop compressor at 130 psi with the same one horn working and the rest nothing. It seems as if it doesn’t matter how much air pressure I throw at it, it sounds the exact same, no pitch difference. It’s gotta be in the manifold or horns themselves, or so I think. It it possible I have tightened the air fitting at the top of the manifold too much? Also what is that large alley key bolt on the front of the manifold? Should that be in any specific position??
I plan on dropping the horns tomorrow and checking them out. How can I check I see if the valve is operating properly?
id get ride of the quick disconnect because unless it I.D is 1/2inch it will restrict air. The ones used for shop air tools will restrict air so…You want volume not pressure.
It’s actually more like a splicing piece, that connects both 1/2" ID hoses. It was used to add more length to the hose, not for disconnect ease. I’ll take some pics of it in the day time for all to see.
By the way, thanks for helping me out!!!
There should be an arrow on the valve so see if its going in the right direction. When the valve opens you should hear a firm solid click. If you have a 1/2 ball valve i would just pull out the lines from the solenoid and plumb it through the ball valve and see what happens when you honk it.
another thing you could do is take the horn off and unbolt all the bells. Then look through the manifold and see if there is any obstructions. Then i would test each bell with a pneumatic blow gun hooked up to your shop compressor.
make sure you got the discs right. i had it before where i put two discs together instead of putting the rubber in between
iNFamasStalin has you on the right track there I reckon. Test each component individually starting from the valve onwards.
Could be that there’s a blockage on the bells themselves or that the discs aren’t creating a seal against their seat. Take them off individually and check them using a shop compressor or something like that. If you can flow air through them it’ll be a seal issue and otherwise it’ll be a blockage. Internally they’re a fairly basic design which you can read about in the Micro Precision K Service Bulletin.
Thanks fellas. I’ll be takin peek at them tonight!
Welcome to the forum. The suggestions here are very good and should help you fix them. If you still have issues try the hornwhistleboard forum.
I unbolted the Nathan’s from the truck, cleaned all of them internally and redid everything. There was some sand inside the horns and some powder coating residue. They were all cleaned and all horns are sounding and it really has that train sound. But after all this I found that the connection coming into the top manifold was very lose, and leaking air. I redid the Teflon tape and things are well… Buttttttttt I have another problem!
They sound great but don’t have that LOUDNESS I hear all on YouTube. Set couldn’t hear them 5 miles away. It’s an authentic sound just not what I expected. I was expecting to have blown ear drums. I think my problem is the diameter of the hose. A black plastic DOT hose was used with a snap in style connectors. I believe that the black hose is not big enough I.D. So it’s not dumping as much air as it should be… What do y’all think? I will post a pic of the set up with the connectors. I would love everyone’s opinion! Thank you!
Thank you Dan! I appreciate everyone’s help!!
Run 1/2" all the way. That should improve things
^^ Agreed - at least 1/2" O.D.
Look inside that fitting you mentioned above. Compare it to the rest of the fittings to determine if it’s a restriction.
Also you said the horn is brand new. Some come with a restrictor plug in the inlet to the manifold. Make sure there is no reducer fitting in that inlet port. It sould be a full 1/2" NPT - measuring around 3/4" inside.
Yeah, it’s likely not enough volume of air making it to the horns fast enough. All 1/2" OD will get you closer. With 10 gallons and that K5, it should blow your mind!!!
I was thinking about that earlier. Usually the manifold tag will say “Over The Road.” thats if there is a tag on the manifold.
Does anyone have a picture of the reducer inlet port you’re talking about? Is it a very obvious fitting? Bc I don’t remember any fittings sticking out of it. Also, what are the large Allen key bolts on either side of the manifold?
The large allens are plugs. Those are additional air inlet ports. The reducer would be inside the opening where you put the air on the bottom port. The hole on the of the manifold should be big enough that your pinky would go right inside . I cannot tell by your pictures but you definitely need at least half inch airline as everyone else has said .