Hitachi Air Tools & Compressors - Recent Questions, Troubleshooting & Support

Easy to remove the cylinder and piston/driver. Remove four head bolts and lightly tap head to release gasket. Push out driver by inserting rod thru nose then remove spring retainer holding the cylinder in place.. With retainer removed the cylinder should pop out. Sometimes the retainer will cause a bur to form on the body of the mailer making it s bit more difficult to remove. Good luck

Hitachi NR65AK... | Answered on Feb 21, 2019

So the first (most obvious but sometimes overlooked) thing - check to make sure the tank drains are closed.
Listen for a leak at the pressure switch - it will continue to leak after the compressor shuts off. If this is the case then you need a check valve (Part # 53A on the breakdown)
If it builds pressure but not enough to shut off and there are no leaks I would look at the valves located in the head (Part # 14 on the breakdown) - piston rings are not a normal failure part on this model but could also cause this.

Hitachi Air... | Answered on Feb 02, 2019

The head pressure is released thru the needle unloader valve at the pressure switch. Notice a 1/4 inch plastic tube (or metal) running from the intank check valve to the pressure switch. After pressure switch reaches set pressure a small tang moves up and presses on the needle valve releasing the pressure. Only a small amount of air will be released. If however air continues to escape from the needle valve, then the check valve is bad.

Hitachi EC12... | Answered on Jan 21, 2019

This problem is usually caused by reed valves or blown gasket between head and valve plate. Easy to check. After the compressor reaches 45 to 50 psi, with compressor still running, remove the air filter and feel for good suction at the intake port. If the air seems to be blowing out of the intake, then valves are bad. If you feel good suction at the intake, then air is leaking from the discharge tubing or other fittings. Good luck

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

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

The reset button is located under the cover visible from the dipstick side of the pump, however, if there is no visible button, then the reset is incorporated within the windings of the motor. The reset hidden in the windings does fail and can be eliminated with much effort. If the motor is cutting out for no apparent reason and comes back on after it cools or if the unit will not power on and all components test good, then suspect internal reset. The internal reset fails if the motor has been overheated many times by low power, or too long of an extension cord or powered by generator.

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

8 ounces of Synthetic Oil SAE15W40

Hitachi Air... | Answered on Jan 19, 2019

2 things The check valve on the tank will not close for 100% rust parts from some metal parts in the pressure pipe metal rings can be used and give problems over time , or under voltage on the power group. are sometimes things that are hidden and not seen .

Hitachi EC89 4... | Answered on Feb 17, 2018

Pressure gage A shows the pressure in the tank. Pressure gage B shows what you have adjusted the output pressure to be. If it is reading 0psi and it is new it is probably because the manufacturer has set it at that level. You have an adjustment valve on the front of your compressor. Rotate it until you see the pressure start to rise then keep going to where you want it set at.

Hitachi Air... | Answered on Nov 27, 2017

insure that there is no debris ie., free from filings from the nails used or or ceck the feeder ports where the nail enters before it lives the port ( check for damage orifice or abstractions to it

Hitachi Air... | Answered on Sep 30, 2017

To remove the fan you will need a decent bearing puller - it is press-fit onto the armature shaft and doesn't come off easily.

Hitachi Air... | Answered on Feb 19, 2017

This problem is caused by either the starter capacitor or the in-tank check valve. Ez to check. With no air in tank, start compressor; if motor hums or has difficulty suspect capacitor. If motor starts, partially fill tank and unplug the power. Check for air leaking at the pressure switch or air coming out of the air inlet (remove the air filter). If air leaking, replace check valve. If no air leaking, again let out all the from the tank and connect power. Allow the compressor to fill and shut-off. After the compressor fills, again listen for air leaking from the pressure switch unloader valve. If air continues to leak from unloader, replace the check valve. Good luck

Hitachi EC12... | Answered on Nov 22, 2016

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