Cant find air leak- air horn system

Nissan11

Nissan11

Well-Known Member
Joined
Nov 29, 2005
Location
Marston, NC
So, Im about to rip all my horn crap off my truck and set it on fire.
Ive got a triple set of air horns on my truck. They are mounted behind my front bumper. Ive got a hornblasters valve mounted under the passenger side door and a 7 gallon tank under the bed, no compressor.
The horns came with a cheap solenoid when I purchased them about a year ago. The solenoid that came with them didnt work so I got a replacement. It worked great and there was no leak in the system for 8 months, then that solenoid quit working. I bought another solenoid just like it and while replacing it, I also changed the gauge on my tank, the fittings, etc. Ever since, Ive had a slow leak, about 10 psi every 24 hours. Ive coated EVERYTHING in liquid soap but can not find the leak. I went from the slip-in hose fittings to the kind that use a little crimp ring and are threaded tight. There was still a leak after that.
I figured the tank gauge was leaking so I changed that but it still leaked.
After than I knew it had to be the solenoid valve leaking. I bought an expensive valve from hornblasters and after I installed it, there was still a leak.
Yesterday, I bought a new, more expensive air hose, all new fittings, new gauge, new manifold and even used a different tank, and its STILL leaking!
Ive replaced everything that could possibly be an issue. Ive been using about 2 wraps of teflon tape on all the threads. Should I use more? Should I put on enough of it so that the fittings get tight before threading all the way in? Any other ideas?
Here is the tank setup. On the other end, the hose threads into an adapter which threads into the solenoid valve.
ai130.photobucket.com_albums_p275_nissan11_Mobile_20Uploads_IMG_7639.jpg
 
Take hose from tank, cap the tank valve, fill, and see if leaks down...if OK, take off solenoid at other end of hose, cap hose, pressurize tank, and see if it leaks down...isolate it to either the tank/valve or hose/solenoid and go from there.
 
BRUISER said:
could the horns be leaking?
Click to expand...

No, the pressure stays between the tank and the valve, the horns only get pressure when the valve is open (blasting.)

kaiser, thanks, I didnt think of that. I know its not the tank or the safety valve on the manifold because when I screw in the valve to shut off the air supply to the line, the tank does not lose pressure.
I will get some plugs this evening.
 
madmax1124 said:
check the schrader valve and the fitting that's attached to it mine leaks some days out of the blue and others it'll be fine.
hope it helps
Click to expand...

Ill check it again. BTW, the packaging with the new solenoid said operating pressure is 150-300psi. I havent put more than 115psi in the tank. Would low pressure cause the valve to leak?
 
1) It appears in your picture you are using liquid teflon tape (white)...you need yellow for air supply
2) Temperature swings will change pressures....the last week or so we have seen some nasty swings down here. Or are you seeing total loss of air? 5-10lbs wouldnt surprise me at all.

But I'm betting on the teflon since the problem originated when you changed the guage and fittings. Then again ive had a leaky guage before also.
 
Ron said:
1) It appears in your picture you are using liquid teflon tape (white)...you need yellow for air supply
2) Temperature swings will change pressures....the last week or so we have seen some nasty swings down here. Or are you seeing total loss of air? 5-10lbs wouldnt surprise me at all.

But I'm betting on the teflon since the problem originated when you changed the guage and fittings. Then again ive had a leaky guage before also.
Click to expand...

I've been using regular Teflon tape, not liquid. It's not the temperature change, I lose 50 psi per week.
I turned off the supply valve on the tank earlier to see if it still leaked.

In the picture I posted, isn't the manifold setup correctly? I assume the shut off valve closes the port directly across from it, not the port below it and to the side. With the valve off, I began unscrewing the hose from the manifold and air began leaking. It turns out, the line, and therefore the solenoid valve HAVE been under pressure, so the leak isn't narrowed down to the tank. Where I have the gauge, is that where the hose is supposed to be connected? This doesn't make sense to me, my old manifold was setup the same way and the valve shut off the air supply to the hose. Do I also have a bad valve at the tank?
 
Nissan11 said:
I've been using regular Teflon tape, not liquid. I
Click to expand...

Teflon tape comes in 2 flavors:
White for liquid
Yellow for Air

Yours is white.

I dont mean the tape is liquid but it is designed to seal liquids.

I can't help on the manifold/valve Ive never used that style before.
 
Mix some dish soap 50-50 with water and use that to check for leaks it will stay on the fittings for a while so you can find the leaks.
 
Ive done that many times. Yesterday I bought a new manifold, gauge, and hose. Its still leaking. I pulled the hose off at the horns (on the other side of the valve) and submerged it in water. No leak, so the valve is good. I put soapy water on all the fittings and didnt see any bubbles, but it is still leaking about 1 psi per hour. I also used a thread sealer this time on all threads.
 
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