High air pressure horn??

[h1crwchf]

I was driving around today and my air pressure guage started to fluctuate, 90-pegged out, and the warning buzzer came on. What the heck is up with that? Is there a high pressure warning? I didn't blow any lines or anything but I can tell she was pressured up! I connected my air hose under the dash and released pressure everytime the horn went off.

What is the problem? Is there a regulator that I need to adjust or replace?

I traced one of the air lines from the pump to the firewall and a round looking manifold type thing but didn't see any adjustments.

Any help would be appreciated!!

 

[73m819]

no high pressure warning, sounds like your low pressure sender took a dump, like the spring craped

 

[jld66]

The horn or buzzer is a low pressure warning. It will sound until there is sufficient pressure to use the brakes. There should be a warning plate on the dash saying that the truck should not be moved until the buzzer stops, indicating enough pressure to provide safe braking. The buzzer normally stops at between 65 - 80 PSI. Normal operating range can be from 90 to 110 PSI. I can't explain why your buzzer seems to go off with increased pressure.

You should drain the air tanks after using the truck. The next time you go to fire her up the buzzer should start as soon as you turn the master power switch on and stay on untill the compressor builds pressure to the minimum safe pressure for the brakes.

 

[h1crwchf]

High pressure buzzer

Everything seems to be working fine on the low end. I do drain the tanks, and when I turn power on, the Low air buzzer comes on until just above 60 PSI on the guage. The only thing that has changed is now the buzzer goes off above 90 or 100 psi and stays on until I bleed pressure below 90 psi. What the heck....

 

[h1crwchf]

point me in the....

no high pressure warning, sounds like your low pressure sender took a dump, like the spring craped

Can you point me in that direction? Where should I look for the low pressure sender?

 

[Brad900]

My truck has a high pressure warning, at 125psi the safety valve opens up on the tanks & vents the air. Very noticeable!!! I got my truck from the navy this way becuase the pressure switch for the buzzer is toast.

 

[SixBuy]

You need a second opinion! hook up a pressure gauge to the aux port on the firewall under the glove box and see what the pressure actually is. Either the dash gauge or the pressure sender for the buzzer is lying.
If the pressure is too high, the unloader on the firewall is probably stuck. I took mine apart and cleaned it and readjusted it (the screw on the end is the adjustment - 1/4 turn makes a big difference.
The air pressure gauge is the only mechanical gauge on the dash; the rest are electric. The sender unit operates the buzzer only.

Like the man said - when the relief valve goes off, you'll know it!

 

[73m819]

the low sender is up under the dash, some times a low air sender will have a internal leak that pressureise the spring side at high pressure, so with the spring and being pressureised it thinks that you have low air at 110#