Emglo M790-HC4V regulator leaking our blow-by holes

by Dick Netzer
(Olympia, WA USA)

Emglo M790-HC4V  air compressor

Emglo M790-HC4V air compressor


I have an Emglo M790-HC4V. Recently the regulator valve started blowing air out the 2 holes on each side of the plastic nut where the base of the regulator screws into the compressor.

The regulator knob was very hard to turn.

I ordered the Emglo replacement/rebuild kit (P/N:OM-AM-RK) for the regulator. After installing the new kit, it does the same thing, except I can now turn the new regulator knob.

I don't know what to do at this point.

Any help would be appreciated.



Comments for Emglo M790-HC4V regulator leaking our blow-by holes

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Aug 02, 2015
Emglo leaking air
by: Bill

Dick, start by cutting the power, empty the tank of all air, pull the tank check valve (see that page if you are not sure what it is) and ensure that the check valve is working.

Air should only pass one way through this valve. If air flows both way, then the valve is pooched, and you need to replace that.

Please do this, and then advise if your leak continues.

Aug 02, 2015
Blow by
by: Dick Netzer

Yes, the air blows by while the compressor is running and it will run forever not building up any pressure. If I unplug it, it continues to blow by until it is empty.

Jul 26, 2015
Emglo M790-HC4V regulator leaking
by: Bill

Is air blowing out of the regulator while the compressor is running, when it fills to cut out and the motor stops, or both, Dick?


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