20 Most Recent Craftsman 33 gal Air Compressor 6 hp Horizontal k Oil Free Pump - Page 3 Questions & Answers

hi,
one thing that would be worth checking is the pressure release valve which is usually located on the bottom of the unit. This valve is suppose to be used each time the unit is turned off. For obvious safety reasons you should release the pressure from the tank each time you are done using it. If this valve is leaking or was left open then you will not be able to achieve the desired full pressure. Just checking if this is tight may be your solution! Hope this helps!

Sounds like the reed valves in the head failed. you need to replace the head (usually cheaper to get a new compressor)

TRY LETTING THE AIR OUT MOTOR IS PROB SEIZED,

It could be one of several things. The first thing to check is if there is power getting to the pressure switch, this is best done with a multimeter - check that you have a line voltage reading at the terminals where the power cord connects to the switch. The next point to check is the switch itself, if the contacts are closed when there is no pressure in the tank, again the multimeter can be used, if there is a reading across the contacts it means that the contacts are open. If they are closed the starting problem could be the start circuit on the motor, either the start capacitor if it is a capacitor start motor, or else the start centrifugal switch and the start windings.

Take care when working on the wiring and motor while checking the circuitry. If you are not sure about working with electricity rather work with the power plug unlugged and use a continuity type tester to check the circuits, Here you would look for continuity in the power cord and also across the pressure switch contacts. For the capacitor, replace it with one of the same or higher voltage and the same capacitance, remembering that a capacitor stores electricity and can deliver a nasty shock even when disconnected for a while.

Hi Frank and welcome to FixYa, I am Kelly. This pump motor has 2 capacitors on on top and one behind the rear gaurd. You should isolate the capacitors by removing one wire from them and then test them with a meter. Probe both terminals. Watch for a momentary jump on the meter and then drift to infinity. Do this with BOTH capacitors. If they check good then inside the motor there is a centrifugal switch that slides side to side on the armature shaft. If the slider is stuck or the switch terminals that it presses against are burned yu can have the symptom you describe. The bad thing about this switch is I have ot found a source for it anywhere. You either repair the contacts or you replace the motor. The motor is outrageous in price. I see them retail from $249.00
http://www.qualityaircompressors.info/?s=Z-D23360
to just over $417.00. If you determine you need a motor... take some time shopping for a replacement. The motor part number is: Z-D23360 or Z-D26712 (replacement / alternate for original.)
Primary motor from Sears:
http://www.searspartsdirect.com/partsdirect/part-number/Z-D23360/0009/919?pathTaken=partSearch&filterPart=&pop=flush&prst=0&shdPart=Z-D23360

Alternate motor from Sears:
http://www.searspartsdirect.com/partsdirect/part-number/Z-D26712/0009/919?pathTaken=partSearch&filterPart=&pop=flush&prst=0&shdPart=Z-D26712

^^--I have to assume that the first number is the whole pump motor assembly and the 2nd number is the motor only.

Start capacitor 625622-001 (grainger website) or original pn that is only availble through distributors of 625622-1 (grainger adds a 00 before the final number)

Make sure you read the contents of this link:
http://www.bobvila.com/forums/Tools/posts/41656-6-hp-30-gal-1-stage-compressor-won-t-start-trips-breaker-fyi

Thanks for choosing FixYa,
Kelly

Almost all of these failures are one of three things: The MAIN check valve, usually located right where the pipe goes into the tank from the compressor. Contamination of the seat or wear is cause of this failure or a broken spring. The second is a failure of the compression relief valve to close. This is often a small pintle valve that is sometimes a part of the pressure switch OR on the larger compressors it sometimes is at the back of the compressor and is moved by speed speed govenor like weights inside the crankcase. The valve is outside however with a pipe up to the heads. A third possibility is failure at the head check valves. These are not pressure holding but only hold short term during each stroke. The possibilities are in order of most probable to least.

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

The HP is to low for the 33 gallan copasity of the tank 6 hp is not enough If you are trying to run things that draw a large CFM . The disgin of the mechine is incorrect sorry its one mans oppoin the thing can't do what it says it can

Are you a mechanical type person? There is a fast and easy way to test the motor but it is not recommended for anyone who doesn't do this for a living. I have replaced 4 shaded pole motors in the last 3 years that did the same thing and never had a problem with a capacitor start or capacitor start/run motor. If the motor hums, it is trying to run. Try giving the stator help getting started while the motor is humming. Use a small piece of wood or soft plastic. Any non-conductor will do. Look inside the rear of the motor and you will see the field coils around the outside surface and the stator is the round thing in the middle of the motor that rotates. Use the non-conductor to start it turning in the direction it would normally run while the motor is humming. If the motor starts and runs ontill the pressure switch shuts it off, the motor is bad. If it has a capacitor on it, try replacing that first. Please let me know how this works out for you.

It sounds like the pressure safety valve could be acting up. It is designed to open when the tank pressure it too high and they don't always reset until the pressure is down to nothing. Some models have them included on the gauge manifold and some on the top of the tank under the cover. It is also possible that the upper limit on the motor switch is set a little too high which would also cause the valve to "pop" before the compressor shuts off.

The motor is dying on your compressor. If it is still under warranty take it back. If you replace it do not get the oil free design. They are not designed to be fixed.

If the ring supercides the original one a bulliten should be enclosed with the new replacement part.
Call Sears 1-800 number to verify before using

reason for its use is to drain any condensation buildup from the inside of the tank that can corrode

not only the inside , but any components that may be attached to your tank. hope this helps !

sounds like it could be starting on load eg starting against a pressure, if you drain the receiver down will it start ok then, if so you probably have a faulty non return valve letting pressure back onto the head. If it is not that the capacitor on the motor could be faulty.

check for correct voltage; 240 volt motor on 120 volt line?