lets talk air compressors. Help me

[SigSaurP229]

It has been a rough weekend for my air compressors. I have a Kobalt and my dad has a Craftsman.

The Kobalt blew the tube that runs from the motor to the tank, and I can't find a replacement anywhere.

The easiest solution was to go get my dad's Craftsman and all will be right in the world. I feel horrible now because the first time I tried to use it I plugged it in the motor hummed for a few seconds (did not start) and tripped my 20 amp breaker. No extension cord.

So I called my dad and he said it has been sitting in his shed for a year untouched and I could hear water sloshing around in it. (not good).

I opened the bleeder valve and this is what happened.

I got the motor to start but only with the bleeder valve open, and once with the bleeder valve closed it started once but emptying the tank it wouldn't refill it just hummed and then tripped the breaker. The motor and piston turn easily by hand. It is a beltless direct drive.

I dont' even know where to begin diagnosing this. I have rebuilt starters and such before.

 

[oldjeep]

Re: lets talk air compressors. Help me

Take a picture of your motor/pump. From the description it sounds like an oil-less compressor, which is basically throw away - not rebuild able.

 

[MTboatguy]

Re: lets talk air compressors. Help me

I replaced my tube that goes from the motor to the tank on one of my compressors with copper tubing. Could you post a pic of your kobalt of the area where the tube blew?

 

[matt167]

Re: lets talk air compressors. Help me

The tube blowing is no big deal. 2 new Compression Ferrules ( 3/8" most likely ) and some copper tubing. The compression fittings are likely non standard thread but 3/8" ferrules will work fine.

This is a compressor that I put a bigger pump on because the orig pump quit and I had the brand new pump.

 

[CharlieB]

Re: lets talk air compressors. Help me

Look to see if the Craftsman motor has a capacitor on it. It may be bad and causing the hard to start condition.

 

[MTboatguy]

Re: lets talk air compressors. Help me

The tube blowing is no big deal. 2 new Compression Ferrules ( 3/8" most likely ) and some copper tubing. The compression fittings are likely non standard thread but 3/8" ferrules will work fine.

This is a compressor that I put a bigger pump on because the orig pump quit and I had the brand new pump.

Same exact thing that I did on mine, The last compressor I bought new actually had copper installed on it from the factory.

 

[SigSaurP229]

Re: lets talk air compressors. Help me

OK the Kobalt compressor I was able to find a replacement tube online so that issue should be resolved in about 5 days.

 

[SigSaurP229]

Re: lets talk air compressors. Help me

Look to see if the Craftsman motor has a capacitor on it. It may be bad and causing the hard to start condition.

It appears to have two capacitors on the back. one black and one white. I don't have any pictures of the motor as I am at work.

 

[DirtyOldBoat]

Re: lets talk air compressors. Help me

I'd be careful "fixing" that Craftsman...you can't fix a rusted out tank. Cheap modern compressors like that come with incredibly thin tanks to begin with. Unfortunately with the box store oilless compressors, it's usually time to throw them away once anything goes wrong. I would bet Sears still sells all the parts, but it might cost more than a new one to rebuild.

I have a similar 25 gallon compressor that I got with some other stuff on craigslist, there must have been 2 gallons of nasty water inside. Looking at the rust, there was no way I could ever trust that tank with compressed air again. I plan on turning the tank into a "gas caddy" for the boat.

 

[Nickypoo]

Re: lets talk air compressors. Help me

Oil-less compressors are really crappy. Like oldjeep said they're basically throw-away. I had a craftsman one with the little compressor at the top of the tank. When the motor blew up (literally throwing sparks) I converted the tank into a reserve air tank and got a used oil filled compressor off craigslist.

 

[bigdee]

Re: lets talk air compressors. Help me

Oil-less compressors are really crappy. Like oldjeep said they're basically throw-away. .

And NOISY Throw it away and get a direct drive oil filled crankcase HF cheapie. Just make sure to add oil, they ship without it!
I bought two because they were cheap and I thought it would be nice to have a spare....that was 9 years ago and haven't used the spare yet.

 

[Fishing Dude too]

Re: lets talk air compressors. Help me

My oiless comp is 10 years old and going strong, my big comp at the other house is 15 and still going stong. Guess it's how they are taken care of.

 

[gm280]

Re: lets talk air compressors. Help me

Two issues here. First, ALL compressors regardless who manufactured them, will get water buildup inside. It is the nature of the beast. When you start compressing air/humidity the water doesn't compress and drops out of the air collecting in the tank. Drain your tank daily or weekly or even monthly as needed. You will always get lots of water out of them regardless of humidity conditions...that's a given. And for the starting problem, yes, those capacitors are starting capacitors and could easily be bad causing your startup problem. Contrary to what some think, those compressor tanks are tested to much more than the compressor will output in pressure. Meaning the tank is not shot just because there is rusty water coming out of it. In fact there should be a relief value installed somewhere on the tank as well. So it is not going to be a problem either. That value will open up if over pressured should occur. If you do know how and try to check those capacitors, be very careful as they can hold a charge and give you a shock. So disconnect the capacitors and short across the capacitor terminals (with the compressor unplugged from the AC outlet of course) before testing them. An analog meter will work better testing those capacitors then a digital meter. You can see the needle swipe along the scale as they charge to the meter’s voltage. And if they do, they are probably okay. If they don’t charge up, then it is time to replace them. IF all that doesn’t work, then it is time to look for a new compressor. But look for a two stage cast iron type with oil. Oil-less designs are just not a long term compressor type but for mere simple filling up tires and such...

 

[bigdee]

Re: lets talk air compressors. Help me

Oil-less designs are just not a long term compressor type but for mere simple filling up tires and such...

We used a Kobalt oil-less compressor for a temporary industrial application,it ran 24/7 for 30 days then it was toast.
Some of those 120 volt compressors are maxed out in size for a 20 amp circuit so if your voltage dips about 10% during start up these motors won't develop enough torque to start. You may want to try plugging into another circuit first. While starting capacitors do fail,it is not that common...they usually fail with age,not use. One more thing to check is the bearings. Any play that would throw the armature off-center would also cause high current and non-start issues.

 

[DirtyOldBoat]

Re: lets talk air compressors. Help me

Drain your tank daily or weekly or even monthly as needed.

Contrary to what some think, those compressor tanks are tested to much more than the compressor will output in pressure. Meaning the tank is not shot just because there is rusty water coming out of it. In fact there should be a relief value installed somewhere on the tank as well. So it is not going to be a problem either. That value will open up if over pressured should occur.

This is *REALLY* bad advice. First of all, all air compressors need to be drained after every use. Not weekly or monthly. If you've let water sit in there for a week or a month, it's been way too long. Yes, air tanks are tested to higher pressures than 120 PSI or whatever the cutoff pressure of your compressor is. This has NOTHING to do with rust. Once a tank starts to rust, especially as bad as shown in the pictures, there is absolutely NO WAY whatsoever to determine whether it is still sound, besides having the tank hydrostatically tested. The fact that it has a relief valve again has nothing to do with the rust. Cheap consumer air compressors such as these use VERY thin tanks to begin with. (given the size it's likely not ASME rated)

The fact is, rusty air tanks give out all the time. Do you want to be around when it happens?

 

[Alan_Scott]

Re: lets talk air compressors. Help me

Automatic Compressor Drain Kit

I installed one of these about 6 years ago and it's still doing the job. Right after install, it melted to the plastic air line running to the bottom so I replaced the upper 3 or so feet with copper and haven't had and problems since.

 

[bruceb58]

Re: lets talk air compressors. Help me

I am getting one of these and wiring it up so it only comes on when the compressor is running:

New Electronic Auotmatic Tank Drain for Air Compressors - Amazon.com
Like the previous poster said, you need to drain after every use or during use which this valve does.

I am going to be purchasing a new 220V Champion compressor for my garage.

I would never own an oil-less compressor. Too loud!!!

 

[bigdee]

Re: lets talk air compressors. Help me

I am getting one of these and wiring it up so it only comes on when the compressor is running:

New Electronic Auotmatic Tank Drain for Air Compressors - Amazon.com
Like the previous poster said, you need to drain after every use or during use which this valve does.

I am going to be purchasing a new 220V Champion compressor for my garage.

I would never own an oil-less compressor. Too loud!!!

Good find,good price Bruce. I used quite a few of those on industrial/plant air systems

 

[matt167]

Re: lets talk air compressors. Help me

I have seen rust compromised tanks. I have discarded some of these tanks myself. One tank I had developed a pin hole, which was drained and drilled ( for safety ) right before it met the scrap pile.

Rusty colored water does not mean a tank is junk, but when you drain multiple quarts of water out of a tank that has been sitting, it's probably time to chuck it, especially if it's a cheapie. A tank should be drained after every use.

My little 110V HF 90234 ( discontinued, built by Campbell Hausfeld ) compressor will charge my black iron air system with at least a pint of water in an 8 hour ( intermittant ) service period.

 

[bruceb58]

Re: lets talk air compressors. Help me

Start capacitors bleed off on their own. No need to worry.