Air Tools & Compressors Logo

Related Topics:

Will Grant Posted on Nov 04, 2018

I have a Mikita MAC2400 air compressor that recently stopped working correctly--it cannot build pressure over 40psi and the motor continues to run non-stop.

Some info: The compressor builds air in the system at the same rate when it worked until it reaches 40psi and then stops building pressure, but the motor continues to run. I turn the compressor off and it continues to hold pressure at 40 psi for at least 24 hours, after which, it goes to 0 psi. Before when I first got the compressor it would hold the air in the tank for much longer at least a week.

1 Answer

Nicholas Lynch

Level 1:

An expert who has achieved level 1.

MVP:

An expert that got 5 achievements.

Habit-Forming:

Visited the website for 3 consecutive days.

New Friend:

An expert that has 1 follower.

  • Contributor 40 Answers
  • Posted on Nov 04, 2018
Nicholas Lynch
Contributor
Level 1:

An expert who has achieved level 1.

MVP:

An expert that got 5 achievements.

Habit-Forming:

Visited the website for 3 consecutive days.

New Friend:

An expert that has 1 follower.

Joined: Nov 11, 2014
Answers
40
Questions
2
Helped
12115
Points
92

This could possibly be, you have some water from condensation buildup inside the tank, liquid does not compress. Before this next step make sure the tank is to 0 psi! Now, there should be a relief valve Wingnut on the bottom. Loosen the wing nut and drain as needed. Then retighten the wingnut (Do not overtighten). Plug the compressor in and try it. My second suggestion is, the psi adjustment pressure knob could be faulty replace as needed!

5 Related Answers

Anonymous

  • 1 Answer
  • Posted on May 04, 2009

SOURCE: EC-12 runs but only builds to 35 psi and continues to run

so i came to this web site for help. where is the help? are we troubleshooting? come on man! what is this? my compressor runs and runs but does'nt build up pressure. it aint the pressure gauge, dummy. its is a problem with some kind of valve that is supposed to kick on- or off when the pressure gets low enough. problem is which valve and how to fix it! and to the guy whose compressor hums, dont use more than 25 ft of cord, and use the correct size cord and the correct power source.

Ad

Lee Glascock

  • 384 Answers
  • Posted on Apr 02, 2009

SOURCE: compressor runs fast but air pressure stays low

look for safety valve pull to reset

Anonymous

  • 19 Answers
  • Posted on Mar 16, 2010

SOURCE: pressure on airtank stop at 40 motor steal run

Usually in th pressure switch (which is where the electrical wires go to and where the on/off switch is) there is a bolt that sticks up in the middle with a spring over it. The spring is held on with a nut, and if you turn the nut in it should let the pump run longer because it puts more pressure on the spring keeping it from popping up and cutting the power off to the motor. im not sure what a difference one turn makes so i guess just do it little by little and dont exceed the tanks max, PSI. Hope this helps you!

duane_wong

Duane Wong

  • 6826 Answers
  • Posted on Jul 05, 2010

SOURCE: will not build up pressure

worn out pump on the compressor, or leak in tank.

Anonymous

  • 36 Answers
  • Posted on Jul 30, 2010

SOURCE: 33 gallon craftsman reaches 40 psi. Motor

check head gasket

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

0helpful
1answer

Mac2400 leaking air at oil breather hole

I have read both your questions and after taking both into consideration it sounds like it needs new piston rings. On a gas engine it is called blow by but both have a piston with rings on them, as they wear the end gap gets bigger and bigger allowing compressed air to bypass the rings into the crankcase where the oil is, the breather is there to allow air from the room to enter and exit as the piston goes up and down to avoid pressure or vacuum in the crankcase, the air on the top side of the piston is supposed to go into the tank but in your case some of it is going around the piston rings and into the crankcase building pressure and blowing oil out. There is not much inside a compressor like a gas engine, taking the head off and the oil pan should let you take off the connecting rod bolts and push the pistons out the top. This answer is based on the two comments of cant build all the air pressor and it is blowing oil out the crankcase breather. If you hit the 80 psi and unplug the compressor can you hear air coming from the limit switch box that the power cord goes into ? I will wait for your answer to continue.
0helpful
1answer

I have a Craftsman compressor Model # 919-15292 2. The compressor stopped building pressure because air was continually being released through the unloader valve. I have replaced the unloader valve,...

you must have wired the new pressure switch incorrectly .when the pressure switch opens it will release the head pressure so your compressor must be running with the pressure switch contacts open should be 4 connections 2 marked motor which is from your compressor and 2 marked line which is your power coming in
0helpful
2answers

Air pressure only builds up to 45 lbs. compressor continues to run. I drained all the air and it still only builds up to 45 lbs.

The check valve is not holding the pressure back off the head,therefore allowing the pressure to build up fully.
0helpful
1answer
0helpful
1answer

Air Compressor stalls when it reaches @ 40psi. Have a

You need to find an amp probe from someone and use it to monitor the amps as the compressor is building up pressure. If the amps start increasing dramatically as it nears the stall point it would seem that you have a seizing problem or electrical motor problem. This answer only applies to the exact statement that you gave. ( Air Compressor stalls when it ). Mike [email protected]
0helpful
1answer
2helpful
2answers

EC-12 runs but only builds to 35 psi and continues to run

It looks like there might be a knob which sets the max air pressure coming from the compressor. If there is one, this may have been turned down.

There are usually 3 pressure settings on an electric compressor. Compressor max, pressure switch cut on, and pressure switch cut off.
Not finding what you are looking for?

370 views

Ask a Question

Usually answered in minutes!

Top Psi Air Tools & Compressors Experts

john h

Level 3 Expert

29494 Answers

ADMIN Andrew
ADMIN Andrew

Level 3 Expert

66963 Answers

Kardoc

Level 3 Expert

7503 Answers

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

Answer questions

Manuals & User Guides

Loading...