Problem building air pressure > 60 PSI

[PaFarmer]

I have a deuce with air assist. I have had the truck three years and it has worked fine. Recently it will not build more than 60 PSI and the buzzer pretty much stays on. I adjusted the regulator on the firewall in and out and it would not change the air pressure up or down, the truck stays at about 60 PSI. I disassembled the regulator and it seems to be working fine.

The pressure does not fall below 60 when I drive the truck and the steering and brakes work fine.

I cannot find any air leaks when the truck is shut off and it seems to hold pressure the same as my other deuces do after shutting it down. I cannot tell if it is leaking when the truck is running but I cannot feel air coming out any of the lines.

When I first got the truck, the air pressure was set too high. It would vent from time to time. I turned the pressure down to about 100 PSI and things have been great until this issue.

I tried a search but there is so much information on air pressure that does not address my issue.

Thanks in advance for any assistance.

 

[Katahdin]

Had a similar problem, try replacing the governor. Its about 12 bucks at NAPA #H284358

Note, the NAPA air governor may not be same model that you have, as there are several different types, but you should be able to plumb it in and make it work.


P.S. Berks County eh? My In-Laws and a college friend live in Fleetwood, I've visited that county a lot.

 

[dozer1]

Had a similar problem, try replacing the governor. Its about 12 bucks at Napa #H284358

That does sound like a good place to start. Other then that, you must have an airleak that for whatever reason, only exists while the truck is running. Just hard to hear it. Lastly, could the compressor have went out?

 

[pjvargas]

Troubleshooting steps from the tech manuals:
Problem: BUZZER DOES NOT SHUT OFF AND AIR PRESSURE GAGE READS BELOW 60 OR 65 PSI.
1) CHECK AIR RESERVOIR DRAIN VALVE UNDER LEFT SIDE RUNNING BOARD. FEEL IF DRAIN VALVE IS LOOSE. TIGHTEN IF LOOSE.
2) CHECK BOTH REAR AIR COUPLING SHUTOFF VALVES. MAKE SURE THEY ARE OFF (CLOSED).
3) CHECK AIR COMPRESSOR DRIVE BELT AND PULLEY. LOOK FOR BROKEN BELT. LOOK FOR SIGNS OF OIL ON BELT AND COMPRESSOR PULLEY. CHECK AIR COMPRESSOR DRIVE BELT ADJUSTMENT. ADJUST LOOSE DRIVE BELT. REPLACE BROKEN OR OILY BELT AND CLEAN COMPRESSOR PULLEY (IF FOUND OILY, FIX LEAK).
4) CHECK COMPRESSED AIR LINES AND FITTINGS (FITTINGS AND METAL TUBING CAN BE RUINED BY OVER TIGHTENING; TIGHTEN FITTING UNTIL LEAK STOPS). CHECK FOR LEAKS USING SOAPY WATER (LOOK FOR AIR BUBBLES). REPLACE BROKEN OR CRUSHED AIR LINES.
5) CHECK AIR GOVERNOR ADJUSTMENT PER TM 9-2320-260-10. AIR PRESSURE SHOULD REACH 120 PSI BEFORE UNLOADING. IF AIR GOVERNOR CANNOT BE ADJUSTED, REPLACE IT.
6) REPLACE AIR COMPRESSOR.

 

[Katahdin]

Thanks Pjvargas, yeah, look at #5. If he had to turn it down to 100PSI to keep it from unloading then it sounds like the governor was starting to go and then went.