Compressor runs to pressure shuts off sounds like its bleeding down then tries to restart but just locks up if i manually bleed it to 30- 40 lbs and turn it back on it will restart,this only happens intermittently sometimes it works perfect for hours. this compressor has little time on it 10 hrs total?

Is the regulators flow in correct orientation?

Compressors are set up so when the motor shuts off the air in the compressor pump head is bled off so the motor can restart easily when the pressure in the tank drops to the restart point. The usual culprit for problems with this system is the tank check valve. It's where the line from the pump goes into the tank. It lets air into the tank then closes when the motor shuts off and the bleed-off valve opens. The spring could be broke or the valve is dirty or jambed. Sometimes they can be cleaned but more often than not they have to be replaced. The bleed-off valve on the pressure switch could be the problem but that's rare. If it is the bleed-off valve, you'll have to replace the pressure switch.

This compressor has a bleed valve under the tank. It is used to drain pressure. It may be cracked open.

Is you air regulator working? I suspect your reed valves in the head need replacing as they may not be holding pressure over the 45psi that you mentioned, and are allowing the air pressure to defeat them which allows the psi over 45 psi to bleed back into the air compressor cylinder.

The pressure bleed valve is not working when the compressor shuts off. It is supposed to drain pressure from the compressor air line to the check valve and pressure regulator switch so that the compressor restarts with low pressure in the output line.

your max pressure switch is faulty, and shutting off the power early. replace switch, check owners manual for location(should be near power wires)

No, there is a problem with the check valve . the check valve is allowing the unit to start with a load on it . replace the check valve it will fix the problem

sounds like you need a new check valve which should be somewhere between the compressor outlet piping,tubing,etc and the tank which prevents the air in tank to back feed to the compressor which would cause hard starting and could damage the motor easy way to check is when you shut off the compressor with some air in the tank if the check valve is bad it would continue to bleed air out out the unloader valve .the unloader valve on your unit is most likely part of the pressure switch when the unit shuts of it should only bleed down the pressure in the pump so it would make it easy to start when needed hope i didn't confuse you

I have worked on many makita compressors and have run-across this problem on a few of them. Your compressor has a check valve that is supposed to hold tank pressure after the switch reaches set pressure. There is an unloader valve built into the pressure switch that releases the pressure in the discharge hose after the unit shuts off. The unloader allows the compressor to restart with-out any pressure in the discharge line. If the brass check valve is leaking pressure back into the system, air will leak out of the unloader valve. Follow the discharge line to the tank and you will see the brass check valve. To test valve for fault, run the compressor till it builds around 80 psi and unplug the unit from the wall outlet. Remove the 1/4" hose connector from the check valve and check for air leaking out of the valve. If it is leaking you can order form www.toolpartsdirect.com. or call the makita 1-800 number. The price is about the same. Good Luck on your repair.

Everything I read in the owners manual suggest you take unit in for a trained service tech to repair. It could possibly be a few things causing this but from what I can see there are not that many replaceable repairable parts for this. Good luck