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

Unfortunately, you don't provide a Model number 'V73' is Version 7.3 of the Software running the control panel. They have model number like in the front page of this manual, and in this particular Manuals website you can use the search feature. https://www.manualslib.com/manual/1652200/Hitachi-Next-Series.html#manual ..

the regulator is used to control pressure. Is the knob turned completely clockwise. page 9 of instructions. Don't have yours copy and paste link https://www.metabo-hpt.com/docs/default-source/default-document-library/ec89_om.pdf?sfvrsn=51a32c66_0

I would check the main switch/speed control for a fault, assuming the battery is not exhausted that is.

notify a dealer or manufacturer

First, you have to determine how it is attached usually they are screwed or bolted into place or simply held into place by clips or pressure. But there are many different models so please post the model of your machine so it can be identified or even a photo.

Question edited for full 'make model (what is is)', plus 'Hitachi'! Question moved from Televisions category to the correct one. I thought there may be a video, but there isn't. There is a previous Fixya question and other help in the link though. https://www.google.com/search?q=hitachi+ec119sa+replace+regulator+knob ..

if you replaced capacitor exactly like it was remove and no wires switched you have a bad motor.

Check the circuit breaker reset located under the shroud above the dipstick. If the unit hums but won't turn, first drain the air completely and then try it (If it starts, your problem is most likely the check valve located on the tank) 2) Unplug it and carefully use a thin screwdriver to turn the fan blade - if it spins and is not bound then try it again. If it still doesn't start I would look at the start capacitor located under the shroud

The EC12 holds 8 ounces I recommend synthetic

This is a common problem with this model - the typical reason for this is overdriving the piston which is usually caused by air pressure being too high. It can also be from using it on thin or soft wood (using it to nail plywood to plywood etc)

This is not replacing an o-ring, unfortunately, this involves replacing the manifold #887-499 which contains the regulator. There are no regulator parts available.

check and test cut out may be faulty or failing

If u are talking about the bleed off that blows when the compressor shuts off. It should blow down for a short period then stop. If it dont stop your tank check valve is bad.

There is no battery on that air compressor.

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

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.

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.

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

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.