After air compressor reach the max. pressure it starts losing air and now there is fluid in the gages. and when it tries to refill it shuts off

Most pressure cut off switches have an adjustment screw on them where you can dial in the cut off/turn on pressures. Take a look and see if you have the adjustment screws. If you have the switch model, you can try looking up online to see how to make these adjustments.

The pressure switch needs adjusting or replaced. The power cord is attached to this switch. There is an adjustment screw under the cover.

They will run until the air pressure is at the max, then will shut off. This is normal. When you use the air & it goes below a certain level, the motor should run again. If the pressure is not reaching the max value, then the motor may be overheating.

you cant guess at the pressure in the system. and its not a good idea to bleed off any r134a. it is now known to be a powerful green house gas. so should be recovered. however its easy to see what the pressure is. there are low cost gages that come with some r134a kits. that will likely tell you the pressure is low. typically that's what causes the compressor to cycle. there is likely a leak somewhere .. the r134a molecule is very small and its hard to keep things from leaking. you can use soapy water around the crimped rubber hose ends and connectors. that's what usually leaks. there are two ports on the air conditioner .. a high pressure and a low pressure .. the low pressure port is what you add fluid into. its just a valve similar to a tire valve. if you were to push the valve open then refrigerant will vent just like a tire .. but don't ever do that with your finger. it will freeze. unfortunately you will also be venting oil that flows along with the fluid. that can damage your system. if you vent too much then your system will have to be put on a vacuum pump to start over.
1. check for leaks with soapy water. look for bubbles while the system is running. look for oily spots that might indicate a leak.
2. check the low pressure side for proper pressure. chances are it will be low indicating not enough r134a
3. repair whatever is leaking before refilling. use the gage to determine when properly filled.

the system has a pressure switch that makes sure their is always enough pressure on the low pressure side. that's because if the pressure gets too low there is danger of sucking in air and that will damage the system. so if the pressure gets below a set value then it shuts off the compressor. the pressure builds back up and the compressor comes back on then again the pressure drops as the system builds up. that's why it cycles fast . there is not enough fluid to keep minimum pressure while operating. if you have too much r134a then typically it will work but will probably blow out a hose. adding fluid to a leaking system will only make it work until it leaks back out .. sometimes that can last a year or a day, depending on how bad the leak.

The pressure switch needs to be replaced.

The pressure regulator on an air compressor is designed to let the pump motor run until the pressure in the tanks reaches their safe level. While you are using the air the pressure drops in the tanks until it reaches the level where the pressure switch turns the motor on again and refills the tanks to their rated level. The pressure where these two things happen is usually with in ten psi above or below the rated levels because few regulators are so precise and are affected by temperature that they turn and off exactly at the rated pressures. If a pressure regulator is damaged or broken it is possible for the tank to either reach unsafe high levels or not turn on when the pressure drops to where it should restart the motor. If you are in doubt, have the regulator checked or replaced as overpressured tanks are very dangerous.

Hi, my name is John. Welcome to FixYa. Look on the pressure switch and see what the max. is. I have some notes here I will have to locate them and I will post them here if you still having problems, but it sounds like you need to replace the pressure switch. Thanks for choosing FixYa...John

Wiring is incorrect. Do you hear it click when the pressure is reached...if so incorrect wiring.

Yes,but if the max is 125 you don't want to increase it above 110 and set off the pressure relief valve.

Are you talking about the power switch or the trigger of an air tool?
If it is the power switch then how much air are you losing?
At start up most air compressors will lose a small amount of air through the unloader valve. As the compressor builds psi this valve will close. Once the max psi is reached the motor will shut off then a few seconds later the unloader valve will open again releasing the pressure in the cylinder. If your leak does not abate as psi builds you might need to replace your switch and valve.