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Air pressure question?

July 20, 2022, 12:39:33 pm

 My second air tank drops PSI very fast( 3-4 min)  from 125 to 110 and then kinda hangs there until the compressor picks it back up.  It never goes under 110psi.  When I apply the brakes, the drop stops at 110 .
  Sitting here now, engine off , both gauges are the same at  105# and it will drop overnight  to 40-50 and zero in the couple of days.
  I have no audible leaks  and am heading towards the regulator on top of the tank , the brake pedal  valve and maybe the relays.
 
 Engine off, apply brakes and both needles move  together with acceptable air loss.
 Any help ?

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Re: Air pressure question?

Reply #1 – July 20, 2022, 08:06:51 pm

Use a gallon garden pressure sprayer with a soap solution to spray bags, all devices and air lines. Any hardware store will have one for $10 or so. Air bubbles are much easier to see than a leak is to hear. A party bubble solution is the best if a store is in your area.

Pierce

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Re: Air pressure question?

Reply #2 – July 20, 2022, 08:53:07 pm

It passes the bubble test.
  Very little air loss after it is shut down and under 110#
 One tank drops fast to 110
 That tank has the regulator on it. 

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Re: Air pressure question?

Reply #3 – July 21, 2022, 08:51:50 am

The check valves at the tanks leak.  Foretravel stocks a bunch of them so they can be replaced.  The guy that does the service work on motorcades says that is the first place he starts looking for leaks since they seem to always be bad.

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