Just bought a K5la, need some help.

Hello, I am new here. Anyways I just bought a K5la off ebay, more for nostalgia and the history. I always wanted a K5la because its my personal favorite, especially the 80’s versions. This one here seems to have different parts. I did some research and the manifold appears to be early 80s since the numbers are upside down. The number 3 and 4 bells have stamped A’s on them, I only have the 3a pictured but the 4a has the same markings. All the bells seem to be the wide font versions except the #1 bell. I did not take the back caps apart. Three of the snow cones on it are amtrak cones and 2 are nathan cones, all on nathan brackets. I am currently using a makita compressor and 3/8 inch hose with a quarter turn valve but plan to get a GW valve and a tank and possibly bigger hose. Heres a video of my horn below. https://www.youtube.com/watch?v=3f37bsc4APU

If anyone can help me identify it better or tell me if it sounds good that would be greatly appreciated. When I think of an 80s k5la this one sounds different.

Welcome to the forum. I don’t know horns very well but someone here is sure to help you!

Firstly - welcome to the forum and congrats on your purchased of a K5LA. Rather than me regurgitate stuff, you can read plenty about their history here:
http://atsf.railfan.net/airhorns/k5la.html

I watched your video and unfortunately not all is well in camp Nathan with that one. Sounds like you can get barely two of the bells to function. First point of blame could be the compressor. The K5LA is one of the most air hungry horns out there. Make sure you run a 1/2 line and valve to them - the 3/8 will be a little small but should still work for a short bust if you keep your line very short and the pressure upwards of 120+ psi. Keep in mind that the 3/8 hose is not your area of concern - think of the smallest point in the flow system. I bet your Makita compressor will probably have a much much smaller orifice in the tank and the connection.

With a 1/2 line you should aim for around 100+psi flow pressure which may not sound like much but is heaps when you consider it on a 1/2 line output.

There’s heaps of clips online to show you how a K5LA at full song sounds like. If you can’t get them to go properly on a bigger air supply then you may need to look at refurbishing the power chambers. Luckily you can get parts very readily online. Depending on what needs to be fixed you may need to seek additional help from someone who knows how to restore these horns. Do a search for Mike Muha (South Bay Horn Works) - he is one of the best known out there who specialises in fixing old horns.

Anyway, hope a good dose of air will sort things out for you. They’re a pretty sturdy unit and not much goes wrong with them.

Yeah I kind of had a strong feeling all the bells were not getting enough air, mostly due to having a longer 3/8 inch hose. Is there a good place to get 1/2 inch hose? Looks like amazon has some. At least it somewhat works, hopefully it works fully, it said so in the listing, I’m hoping the guy I bought it off of had it working to its full potential. Im guessing It would work fine if I bought a 8 gallon or so tank and had the 1/2 inch hose with a valve. At least it would be better than just directly hooked up to a compressor.

1/2 hose is plenty easy to find most places. Just make sure you buy something that suits your end usage for the horns. Also consider what I said about the compressor (Your airflow is only as good as the smallest point of restriction in your air system - i.e. probably the tank fittings or compressor tank outlet). If you’re considering a vehicle or similar install, buy the stuff that suits it right from the get go so you’re not having to purchase hose and fittings twice.

If you’re not sure where or what to get, give the folks at Hornblasters a call. They’ll help you out with all the right bits you need.

I don’t plan to install this horn on my vehicle, basically just use it every once in a while near my house and keep it with the other railroad equipment. Thanks, I will look into what they have.