INSTALL WITH PICS - K5LA - 12 gal tank - dual 444c's - '08 F250

Here are a ton of pics of my K5LA restoration and installation.

The horn, 12 gal tank, dual ViAir 444Cs, and 1/2" solenoid drain valve were all run with 1/2" OD DOT air line and 12 awg and 14 awg wire into my '08 Ford F-250. Currently I have the horn connected to a 1/2" solenoid valve which is connected to my stock horn via toggle switch. Later I will be installing my manual train horn valve and digital air gauge. I will update pics as I get to it.

A few tips I’d like to share:

  1. Use blue thread locker on all bolts. Use it on the bolts that attach the back caps and the bolts that attach the horn to your vehicle. This will help to keep the threads tight and keep them from backing out while you are bouncing down the road.

  2. Use security bolts to attach your horn to your truck to discourage anyone from trying to simply unbolt your horn from your ride.

  3. Use Rector Seal 5 instead of Teflon tape to seal your fittings. I’ve used tape before and the RS5 does a better job of sealing the threads the first time. Just be sure to allow ample time for drying before applying pressure.

A big shout out is deserved for Garrett and Tiernan of Hornblasters for helping me piece together what was needed to complete my dream train horn setup! Thank you both!

An even BIGGER shout out goes to you guys here on the forum who have been more than willing to share your knowledge and expertise! Thanks a ton guys!!

My shipment of tank, dual 444Cs, valve and fittings, air line, digital air gauge, and t-shirts were all ordered from HornBlasters.

The K5LA was purchased through eBay. It came with about 15’ of air line, another 1/2" solenoid valve, SS bolts for the back caps, and SS security bolts for attaching the horn to my truck.

I stripped the back cap of one of the horns here.

K5LA disassembled.

I used Napa spray paint stripper and it worked great. I don’t believe this horn had been primed previously.

Horns are stripped, taped, and ready for priming. They came so clean I almost left the horn raw and skipped the painting. Here you can see that I covered the opening to the inside of the trumpet with tape. After painting I wished that I had cut an opening so that I could paint the back of the insides easier. Live and learn I guess.

Primed using Dupli-Color® Professional Self-Etching Primer.

The horns were then painted with gloss black and school bus yellow Dupli-Color® Professional Acrylic Enamel.

Bolted straight to the frame which used to hold the spare tire. I used SS security bolts to make it more difficult for any idiot who thinks they can get away with trying to steal it.

1/2" solenoid valve wired into the stock horn. Later a manual valve line will be added also for better control of honking when wanted.

12 gal tank and dual 444Cs mounted to plywood with rubber pads underneath to keep it from sliding. The bottom port has a 1/2" solenoid valve attached for releasing moisture.

Attached to rear ports: 1/2" air line run to valve and horns, Air Zenith digital air pressure receiver, (in the middle you can see the 1/2" solenoid moisture release valve which is mounted to the bottom port), 165 - 200 PSI pressure switch, 235 PSI safety pressure valve. The electrical still needs to be buttoned up. Once it is I’ll update the pic.

The 1/2" solenoid valve is tapped into the stock horn wiring.

Here is the toggle switch between the stock horn wiring and solenoid valve. This switch will be mounted with the digital air gauge.

Now all I have left to do is install the manual valve which will be installed in the cab next to the console, the digital air gauge, and clean up and hide all of the wiring.

Thanks for taking a look and any questions are welcomed!


I will be the first to say that this is a VERY clean install. I like it man! Good job.

agreed, very clean install!

Thanks! Headed now to drop it off at Ford for some warranty work or I’d get those wires hidden and the remainder installed. Got it turned off so the Ford techs don’t kill themselves scaring each other! Lol


Thanks guys! I’ll tell you one thing…the paint job took waaaay longer than I expected. Of course the main cause for that is that I am an extreme perfectionist. That horn has probably 10 coats of paint on it by the time I finished!

BTW I just posted pics of the manual valve and digital gauge I’ll be installing…

awesome install!

Love the school bus horns! Nice paint job and a real nice install.

Thanks man. Yeah I get told I’m driving the short bus or big bannana all the time. :slight_smile:

Hey , Big Yella

I was just wondering why when people mount their horns to the frame why doesn’t anyone use the rubber spacer like the Nathan site does?

Thanks, Jake

Ya know I saw that, but I don’t have one. I’m sure I could find a piece of rubber at the local hardware store and make one. Probably not a bad idea to help with vibration and to reduce the risk of breaking the mount. Thanks for reminding me of that!

Here they are from the manufacturer:

And here is a gasket for each bell:

I may pick up a set of all of these down the road to add to my horns.

That donut is used for a flange mount. The train has a flanged surface the the flanged portion bolts too and the donut is the gasket in between.

So they don’t use the 1/2" npt threads…just seal between the 2 flanges?

Hey BigYella how long to refill from 165 to 200?

Correct… Heres an example. These pics are from a fellow collector ED K. On another forum I’m a long member of. I wanted to give credit for his pictures

Cool so we don’t need that. Thanks for the info! I wonder if the gasket for each bell is necessary? I don’t have any of those and today is the first time I’ve even seen they were available.

Ear2ear - I haven’t timed that yet but plan to do so once I get my truck back from the shop. The only thing I did time was 0-150psi ~ 10min and 0-200psi ~ 18min. So obviously 165-200psi will be less than 8min but I will get a more accurate time for u once I get her back. Once the pressure gets up to 150psi it definately takes the comps working hard to acheive that last 50psi. The gauge moves slower and slower.

That is one awesome setup you’ve built. It’s going to last you for years! GREAT job on the install!

Thanks Matt. Yeah I figured I’d go ahead and drop the time & money into it now instead of wanting to upgrade as soon as I got it and then having to deal with re-doing it down the road. I’m looking forward to that tank being multi-use too as onboard air that could tackle anything from airing up a tire to a construction project needing air tools. That and it just looks hell’a bad! :smiley:

I was just curious on the compressor time - so don’t go out of your way just for me.