Air Pressure regulator

[SixBuy]

Did the parade yesterday and got a 3rd place on the first time out. Problem is the air pressure went off-scale and the relief valve popped off. So we finished with the under dash valve cracked enough to bleed off excess air. Talk about going deaf...

Turning the regulator knob doesn't seem to affect the air pressure and the manuals say replace it. Are those repairable? How do they work. Does air bleed back to the compressor when the set point has been reached to cause the compressor to shut down or is it just the opposite? I'm looking for some way to isolate the problem/ fix it. Anybody been there before?

 

[Gatnom]

<SPAN style="COLOR: white">[3]SixBuy: I have not fooled with mine, but I think it should be an unloader as apposed to a regulator, and should work something like this:<SPAN style="mso-spacerun: yes"> Some type of relief in the adjustable component on the fire wall, upon reaching set point, will allow air pressure back to the compressor which should hold open the intake valve allowing it to spin without compressing any more air.<SPAN style="mso-spacerun: yes"> <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>[/3]

<SPAN style="COLOR: white"><o>[3] [/3]</o>

<SPAN style="COLOR: white">[3]This means your problem could be at the unloader, or at the compressor.<SPAN style="mso-spacerun: yes"> I suppose the first thing to do might be to disconnect the line going back to the compressor and see if you get air pressure after reaching your usual set point.<SPAN style="mso-spacerun: yes"> Just be careful not to severely overpressure the compressor. The internals of the unloader should be relatively simple.<SPAN style="mso-spacerun: yes"> Hopefully that is where your problem lies, if not, you’ll most likely be pulling the head off of the compressor.<SPAN style="mso-spacerun: yes"> I will have to take a better look at my truck to see how it is all laid out.<SPAN style="mso-spacerun: yes"> I know its not much help, but it's all I've got right now. Dave <o></o>[/3]

 

[Gatnom]

SixBuy: Ii just dawned on me to suggest hooking up the unloader valve to a seperate regulated air source. You could then increase the pressure to the valve and see exactly if, or at what pressure, it sends the air signal back to the compressor. It would be alot easier to control
and troubleshoot things that way. I'm at work tonight, so can't get to the truck to look at anything. I have a copy of my TM's here and if I get the time, I'll see if I can turn up anything usefull. Dave

 

[SixBuy]

That's how you get another point on your genius star! Good idea! I've been trying to figure out whether the compressor shut down on pressure or bleed-off and that would answer the question. I checked the air pressure under the dash when the gauge went off-scale and I saw 160 + there. Wow! Good thing there wasn't shrapnel!
I've looked in all the manuals I could and they all say take it to your organizational unit maint. So I'm it!