A3 air pressure issue

[autigers35a3]

Start the A3 this am headed to the Xmas parade.
Outside temp around 38F.
Truck started fine with air buzzer going off etc.
Let truck idle about 10 minutes before I got in to drive off.
Air buzzer still blaring. Never done this before.
Air pressire would build up to 60 PSI... buzzer go off.. then 10/15 seconds later gauge goes to 0 and buzzer goes blaring.
I shut the engine off and got out to listen for air leaking.
Notta. No air leaks.
I start the truck back up . Same thing.
0 PSI to 60 PSI with buzzer blaring etc.
I put the truck in gear and test the brakes with the buzzer blaring. I got brakes.
I then drive about 1000 feet down my street and buzzer stops and sir pressire goes to 120.
Drive the truck in xmas parade and start and stop engine several times and it does fine with air pressure ...
CTIS unit has no power to it. CTIS stuff on tires still in place not removed.
Thoughts?
And yes....doing the search thing!!
Thanks!!

 

[AceHigh]

Mine does it from time to time. In my case it is the air assist system. I have to put some air tool oil in it. Turn off the air assist steering valve on the firewall and see it that helps. Ya never know.

 

[jwaller]

remove the pressure regulator from the air assist system. might not be a problem now but it will be in the future.

Sounds somewhat normal for the A3's. It would not concern me too much. Like the other poster said. put some air tool oil in the system and air packs and let it go. make sure you are draining the air tanks and getting the water out before you leave it for the night.

 

[flyxpl]

Mine did it yesterday at about 20 degrees outside . Idled for about 10 minutes , when I get in the truck the buzzer is going off . I rev the engine a little bit and in less then a minute in jumps to 120 . My geuss is we have moisture somwhere in the system freezing .

 

[doghead]

Others have posted a temporary issue with the air dryer, causing this problem.

 

[3dAngus]

Drain tanks three times, three iteratons when full, then with engine off so compressor is not running.
Then on third time shut the engine down and put your ear up to the instrument cluster. Listen for any small leak next to the air pressure gauge with tanks full of air. You might even want to remove the line from your air pressure gauge and blow out any debris to the gauge and lines.
Retape with new plumbers tape when you put the guage back in.

Small chance but simple to do before you go to any expense. Sometimes some of the moisture will run back to the tank with the compressor off and tanks being completely emptied. Not sure where it comes from, but it's there, and it's good maintenance too.

 

[tie6044]

Take some soapy water in a spray bottle and spray the hoses under the drivers fender for the air assist. If you see a bubble bath suddenly forming you have found your problem. I've had it on 3 trucks that sound the same as yours and after a $10 hose at Napa problem solved. If they don't have the same ends just get a chunk of hydraulic hose and re-use your fittings. They are hard to get into the hose but it's cheaper than having the whole thing made. You can't hear the air leaking but the soapy water will find it.

 

[goodguyzy]

mine will do the same thing from time to time.

 

[sierra117]

I have had this issue as well it always seemed to be the blow off valve on the air dryer getting stuck partially open I just push it back in.

 

[autigers35a3]

put air tool in where? thanks for all the help!!!!!

 

[Rustygears]

Before doing anything. Try closing the air valve located at the rear of the engine in front of the firewall. It's brass. See if you have the same issues when it's shut. This controls the air supply to the accessories like air assist and engine fan control. Do this before taking things apart, etc. Make sure you also have properly serviced the air tanks as suggested in an earlier response. It sounds like frozen moisture. If the air dryer hasn't been serviced recently and isn't operating correctly, lots of moisture collects in the tanks.

 

[goodguyzy]

mine was doing it this summer so I don't think it has anything to do with freezing.

 

[SETOYOTA]

His truck does not have the regulator.

 

[autigers35a3]

correct. truck does not have the regulator. Thanks SE.