20 Most Recent Hitachi EC119SA Twin-Stack Air Compressor with Control Panel and Couplers Questions & Answers


The pressure regulator can easily be replaced by removing the large plastic decorative cover. The manifold behind the cover is the part where the regulator , gauges, and quick connects are attached. The manifold is fed air from the pump via a plastic hose connected to the pressure switch. The regulator sells for about fifty dollars. This part usually fails in two ways. It leaks air from the knob or no air pressure will reach the quick connects. If your problem is no air at the quick connect, you can do a temp repair by removing the safety valve and installing a tee fitting at the port. On the tee fitting reinstall the safety valve and a quick connect on the other fitting. This will give you tank pressure . Good luck.

Hitachi EC119SA... | Answered on Jan 21, 2019


I would bypass the thermal safety and test the unit. Does it go to proper pressure? run it through two cycles. If it looks good, reconnect the temp sensor and use it until a new one can be obtained.

Hitachi EC119SA... | Answered on Sep 14, 2014


hi there, if there is enough air pressure present in the compressor the motor will stop,the pressure switch is working.if there is a good pressure at start then suddenly lost the pressure,there is no maintaining pressure to use but on the pressure gauge appear to be have a good or enough air pressure. check if the pressure gauge have enough air pressure the motor is stop,meaning the cut out limit switch stop the motor,if you loosen the air pressure from the valve until the cut in pressure attain or meet the motor will run again there will be a cycle process of differential pressure of cut in and cut out set up on pressure switch. checking the compressor,be sure there is a high pressure on compressor and the compressor motor is stop,shut off service valve and disconnect unit device / tools from the service valve. if the compressor have enough air pressure crakc down the service valve and observe the pressure until it run again the compressor motor,if the pressure maintain the pressure you need to clean the bench, the problem is the unit device/tool you use is defective, but if the maintaining air pressure in the compressor is lost due to malfuction of motor and the compressor engine. check the pressure switch, check the motor function by loosening the belt and run the motor w/o the compressor engine if it is tripping brought it to service center, check also the lubricant oil,if neccessary change oil.have a nice day and fix my rate thanks a lot.

Hitachi EC119SA... | Answered on Jul 23, 2014


Parts can be ordered form www.toolpartsdirect.com. Air regulator should be adjusted with very little air pressure in the system. If you are adjusting the regulator with full tank pressure, you are overworking the plastic parts within. Over time, water will rust parts inside of the regulator. I would order the complete regulator. You could also remove the regulator part of the manafold and use full pressure to the quick connects. If you need to regulate the air pressure down a bit, purchase a universal regulator and install quick connect fittings. Male fitting to air in and female fitting to discharge port. Install this regulator to one of the quick connect fitting on the a/c. Good luck

Hitachi EC119SA... | Answered on Dec 30, 2013


Easy test to determine problem. Plug compressor directly into outlet without extension cord. Start compressor with no air in the tank. It it starts, fill to 50-60 psi and unplug from wall to stop. Wait few minutes and plug the compressor back in. It it starts, most likely problem is too heavy oil or the use of extension cord. If it does not start after few minutes wait, most likely not unloading due to leaking intank check valve or bad cold start valve (see reference # 47 on your parts list). The cold start valve should release air from discharge tube after few minutes. If the intank checkvalve is leaking, the cold start valve will not work and stall the compressor. If all test ok, then just replace oil with 10 - 15 - or 20 wt. Good luck

Hitachi EC119SA... | Answered on Dec 27, 2012


If your compressor keeps running and only builds to 25psi, I would suspect the reed valves, head gaskets or a leak. With the compressor running spray soapy water on all fittings, around the head area and tank components. If no leak is found, remove the air filter and feel for suction at the intake(make sure head is not too hot). If you feel good suction at first then suction is lost after reaching 25 psi, most likely reeds or gaskets (with bad reed valves, sometimes you will actually feel air blowing out of the intake). Good luck

Hitachi EC119SA... | Answered on Oct 15, 2011


Look at the underneath side of the knob. Many of these have a square molded into the knob that fits over the square shaped adjusting stem coming out of the regulator. The replacement regulator (if you end up having to replace it) is part #885807 (reference number 30) and is $42.88 Here is the link to the parts breakdown.

http://www.toolpartsdirect.com/cgi-bin/schematic.cgi/hitachi/EC119SA

Hitachi EC119SA... | Answered on Jul 18, 2011


The first thing to check is the thermal protector (circuit breaker). It is a small black button mounted on the housing on the back side of the pump motor. The unit will have to cool down before the button will reset. Usuall causes for the thermal protector to pop are: running the compressor on an extension cord, running the compressor on power lines or circuits that can't carry enough amps to run the motor, or little or no oil in the compressor causing excessive friction and heat buildup. If the thermal protector isn't tripped the next thing to check is the pressure switch. If the springs inside are broke or damaged they won't trip the switch to turn the compressor on. If the capacitor(s) are bad the motor will hum and/or try to turn but not have the power to start spinning.

Hitachi EC119SA... | Answered on Apr 27, 2011

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