Question about Makita Factory-Reconditioned 2.5 HP Air Compressor MAC2400

1 Answer

Air compressor pressure not regulating

I have a Makita MAC 2400 twin stack air compressor. I don't seem to have a manual but the regulator does not regulate. The compressor does cut out at around 125 psi but I don't seem to be able to adjust the cut out pressure. I loaned it out and it was this way when it returned. As far as I know, it was working fine when I loaned it out,

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 285 Answers

Usually you cannot adjust the cut out pressure of the tank/motor itself, this is why they have regulators, which regulates the pressure flowing down the air lines (regulators like these dont regulate actual tank pressure cutout). To regulate air flow using the regulator knob, you actually have to have air flowing through the hose while you make the regulator/pressure adjustments as regulators regulate pressure DOWNSTREAM from the actual regulator itself.. so air flowing through is a must. Attach an air blower or something similar and let air start flowing through the hose. Now turn your regulator knob in the "-" direction to decrease regulated pressure. It is best to bring pressure all the way down to "0" first, then open the regulator up (by turning to the "+" side) and pressure will rise until you get to the desired pressure needed for the air tool in use. The tank pressure will still be between 80-125 PSI as the motor regulates and keeps the pressure in the tank between these values automatically, but your line/hose air flow pressure will remain at the regulated pressure (say 40 PSI or whatever you set using the regulator knob).

Hope that helps and makes sense.

Please rate this solution on FixYa!

Posted on Jun 20, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Where can I buy a Makita Mac2400 air compressor regulator

Makita parts are available at A small universal regulator may also work if the fittings match-up. When using a universal regulator make sure that the regulator fits thru the hole in the panel or just adjust the hole size. Universal regulator costs about 20 dollars. Good luck

Mar 03, 2015 | Makita & Sealed Mac2400 Big Bore 2.5 Hp...

1 Answer

My makita model 5200 air compressor regulator will not adjust pressure--replaced with a new one-- no!!

you would need a separate regulator to regulate outgoing pressure and you have only an on/off reguastor.

Oct 14, 2014 | Air Tools & Compressors

1 Answer

Blew off regulator knob

Parts can be ordered form 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

Dec 23, 2013 | Hitachi EC119SA Twin-Stack Air Compressor...

1 Answer

The regulator is leaking air and will not support the air tool I am using

They do not show the regulator as serviceable. It looks like you have to buy a complete new regulator. It is part #410028-E. You can find it on this link reference #42.

Jul 13, 2011 | Makita Mac2400 212 Hp 42gallon Twin Air...

1 Answer

Makita MAC2400 2.5 hp compressor has started leaking from the regulator. Is there a repair for this? Thanks

Replace the regulator, you can get a new one from the home depot or just about any good hardware store.

May 02, 2011 | Makita Mac2400 212 Hp 42gallon Twin Air...

1 Answer

I changed the regulator twice and the compressor still does not stop at the psi where i want it.

The pressure regulator adjusts the line pressure! The pressure switch is what turns the pump on and off. If you are trying to maintain a line pressure with the switch and not the regulator,,, you are never going to accomplish that. I would have to guess that your compressor normally run's between 95~125 psi on the "switch" so if you adjust your pressure regulator to 110psi it will maintain that till the tank pressure drops below that point. then it will drop as low as 95 until the pump restarts again. If you are trying to get the switch to run up higher than that,, "stop now" as you will only burn the thing up by trying to go higher that it was designed to run at from the factory!

Jan 10, 2010 | Campbell Hausfeld 04 Gallon Twin Stack...

1 Answer

Need a new pressure regulator for my ec119sa. Where can we get one. Thanks

Here is a link for an online supplier who sells parts for those

The regulator is marked as a "pressure reducer" (0030) and is $44.80 on that site. Good luck.

Dec 08, 2009 | Hitachi EC119SA Twin-Stack Air Compressor...

1 Answer

Pressure regulator control knob leeks air and will not allow unit to reach cappacity

I assume turning up the pressure doesn't help. The regulator probably has a torn diaphragm. It will need replaced (i doubt you can get a rebuild kit).

Oct 14, 2009 | Hitachi EC119SA Twin-Stack Air Compressor...

1 Answer

What the prop

This is caused by a bad pressure regulator most likley, or you might check the drain on the bottom to ensure it is closed.


Aug 30, 2008 | Campbell Hausfeld 04 Gallon Twin Stack...

Not finding what you are looking for?
Makita Factory-Reconditioned  2.5 HP Air Compressor MAC2400 Logo

885 people viewed this question

Ask a Question

Usually answered in minutes!

Top Makita Air Tools & Compressors Experts

John Trevino

Level 3 Expert

1388 Answers

Billy Mac

Level 2 Expert

83 Answers

Craig Butler
Craig Butler

Level 3 Expert

1723 Answers

Are you a Makita Air Tool and Compressor Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides