Won't build top pressure an shut off

Hi bryon


Here are a few things to check, you may have already checked some of these.


Electricity...Compressors will run best with full 115Vot 15AMP/Or 220V electrical supply from a circuit, over the shortest electrical cord as possible.


Air Leaks..Place your ear close to the compressor and listen for air leaking, if you hear air that is not normal and means you have to locate and repair whatever it is that is leaking.
Check the air unloader valve... The air unloader valve will blown out air when you turned off the compressor, that is normal.
But it should not have air leaking out of it all of the time. If so then it is faulty and in need of repair/replacement.


Valves...If either the intake or exaust valves fail, breaks, or fails to seat, then your compressor will run 24 hours a day and never build up to the correct pressure for shut-off.


Gaskets...Check to see if your gaskets have failed.
You could have a gasket failure between the pistons and you will never know it because it shows no external air leak.
If this situation happens then the air will only cycle between cylinders and never build up the correct air pressure.
One way to check the gasket is remove the air filter, then put your hand over the intake.
Please take time to rate me
Bud
If correct then it will suck you hand against the intake.
If the valve or valves have failed then you will feel the air sucking in and blowing out.


Piston Rings and Cylinder...The piston rings could be stuck,broken, or worn and not allowing the correct pressure to build up in your tank.
A worn cylinder will also contribute to the problem of pressure build-up.



Pressure Switch...Check for air leaks at the pressure switch, it has a rubber diaphram that can fail and leak air out of the system.
Please take time to rate me
Bud

Worn ring and cylinder or bad valves maybe.

Check the pressure switch. The unloader valve is actually in the pressure switch where the small air line from the tank check valve attaches to it. When the pressure switch turns the motor off it then lets the head pressure bleed off so the motor can restart the next time pressure drops in the tank. If it's not working and bleeding off the head pressure the cold start valve (the one with the pin in it) also won't open so the motor can restart and warn up properly.

I can not find a Craftsman compressor with that model number anywhere so here are a couple things to look into. If the compressor fills to 70psi and keeps on running check the valve plate and piston/cylinder assemblies. Check that the valve reeds on the valve plate are not bent, broken or warped from heat. Then check that the wiper (oil less) or pistion rings (oil splash) are not damaged and that the cylinder wall is not scarred up. Any of these will let the compressor fill up to the point where the air pressure leaks past the valves or piston and won't fill any further. If the compressor fills to 70psi then shuts off the problem is in the pressure switch. Some have an adjustment screw or bolt to control when it turns on and shuts off. If you had a drop from 100 to 70 the springs may be weak or broke and you'll have to replace the switch.

Hi
your pressure switch is bad. so it isnt cutting off the compressor. the part number is N003306SV and can be obtained from Dewalt on Servicenet.
Detail

Good luck and hope this helps

check fuel pressure, should be 40 psi.
try 2 things

spray starting fluid in air intake to see if it will stay running. It's fue then.

Try turning key to on nd wait 5 seconds for system to build pressure and pump to shut off. Turn key off, wait for relay clcik noise or 10 seconds. then turn key to ON again and wait 5 seconds to build pressure again. Then start engine. If it starts better, you have a bad check valve in the fuel pump or a bad pressure regulator on the fuel rail (unlikely).

report back

There are several causes for this to occur.
1. If it is a 20-40 switch right out of the box it may not be set correctly. I have had this happen. If it builds to 30psi and shuts right off without straining to build to 40psi adjust the Cut-Out pressure up to 40psi. There are two different adjustments on a well switch. One for Cut In / Cut Out psi and one for Cut Out psi.
2. Lack of head pressure being built by the pump can be the cause. This can be attributed to the wrong Jetting in the pump. IE: A shallow well jet/venturi on a deep well.
3. The pump may have a bad impeller, but the pump will generally really strain to build pressure and a bad impeller will be loud, like grinding at times.
4. Double check the pre-set pressure in bladder tank also.
RJ

Your problem is most likely because of damage to the valve plate or piston & cylinder. If one or both of these are not working properly you'll get partial pressure and the unit won't turn off because the tank never comes up to full pressure. Things to check for are damage to the reeds on the valve plate, they could be bent from overheating or broken from use or wear or damage to the piston seal which can cause damage to the cylinder. If any of these aren't sealing properly the air pressure will come up to a point where the air leaks out faster than it goes into the tank. Without your particular model number I don't know which parts to recommend but if you contact Campbell Hausfeld they'll help you get the right parts.

Run the compressor until there is about 75 psi in the tank and turn it off at the pressure switch. Remove the black bleeder line from the pressure switch:
1. If absolutely no air comes out of the line you may have a bad start capacitor on the motor. Have it tested at an electrical or refrigeration shop or just replace it to see if it takes care of your problem.
2. If you get a short blast (five or so seconds) of air then nothing your pressure switch isn't letting the head pressure bleed off after the motor shuts off. This pressure has to be relieved or the motor has to fight the tank pressure when it tries to restart. Reconnect the bleed off line and turn the motor back on. If it starts normally, replace the pressure switch. If it struggles or won't start it is more indicative of a bad start capacitor.
3. If you get constant air flow from the bleed line the problem is with your tank check valve. This causes the same problem as above. Replace the check valve.

I assume it keeps pumping, but doesn't build any more pressure. That is probably bad valves or rings. If your unit has a crankcase breather, and it is puffing alot of air, look for rings. Otherwise valves.