Horn works up to 60 PSI then nothing

[cllctrtom]

Can someone tell me why my horn stops working when the air pressure goes above 60 PSI? In PA, I need to use it often. Thanks in advance!

 

[badgmc56]

Squirt some WD40 in the air line leading to the horn. That may help.

 

[cllctrtom]

Squirt some WD40 in the air line leading to the horn. That may help.

Thanks Bad.... I'll give it a try!

 

[mcmullag]

maybe the diaphram in there is too tight. they have adjusting screws on the back of the horns, you could try adjusting that when your air pressure is up and see if it works. just an idea.

 

[cllctrtom]

maybe the diaphram in there is too tight. they have adjusting screws on the back of the horns, you could try adjusting that when your air pressure is up and see if it works. just an idea.

Another idea I will try. I had no idea about the adjustment screw. Thanks!

 

[duffman1993]

My question is, (It won't be helpful) Why do you need the horn a lot?? Bad drivers?

 

[Blood_of_Tyrants]

I haven't looked, but I am sure that the air horn operates off an electric solenoid valve. That valve is probably sticky and when the pressure gets above 60 psi, the electric solenoid doesn't have enough force to overcome the pressure pushing on the valve. I would use air tool oil instead of WD-40. If that doesn't help, you get an industrial 24 vdc solenoid for about $40.

 

[Kohburn]

sounds like the solenoid valve is too weak to open at higher pressures.

I replaced my horns with louder/lower ones. I've got the old valve if you need it.

 

[jasonjc]

My 5 ton does the same thing

 

[Katahdin]

Cllctrtom, did you fix your horn problem? Mine is doing the same thing, lubing the horn only makes it work briefly at full pressure. I've cleaned the horn and the solenoid, I'm getting 24 volts, etc. Wondering if my next step is to order a new solenoid or replace the wiring.

 

[steelandcanvas]

If you are getting 24 Volts, why would you replace the wiring?

 

[Katahdin]

I was just thinking the solenoid wasn't getting what little amperage it needs to draw the valve plunger in at the higher PSI. A little background: the wire going into the steering column isn't in the best of shape, I've taped up exposed copper strands from rot in the wire insulation.

 

[steelandcanvas]

Gotcha. Yes, I would replace/repair the steering column wire also. My repair consisted of cutting the bad wire out, and splicing a short piece on to replace it. I used heat-shrink tubing around the butt splice, reconnected and all was good. Don't pull that wire out of the column without attaching a pull wire/string to get it back down the column. Don't ask me how I know that.

 

[Tackettr]

I would clean the solenoid and lube it. Mine was doing someting simular, and it kept getting crud (Rust flakes) from the air system clogged around the valve. If i remember correctly, there is a little screen in it somewhere I had to clean several times before the crud stopped.

 

[Katahdin]

I've been dubbing around with the solenoid and found it is tunable to different air pressures by relieving some of the tension on the plunger spring. This can be done three ways: (1) thicker O ring so the brass fitting doesn't need to threaded in as far to create an air pressure seal (2) clip several coils off the plunger spring to weaken it and (3) thread the brass fitting in and out as necessary to fine tune the amount of air that is released when the solenoid is activated.

On the test bench its working much better now, now I just have to install it back in the 109 and hope for the same results.