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This article will serve as a hub for all Kobalt air compressor not building pressure, related issues. It’s a very common problem for Kobalt air compressor will not build pressure, and so, this article will present the reasons why this occurs, along with current reader questions and answers.
Table of Contents
Reasons Kobalt Air Compressor Won’t Build Pressure
The most likely reasons why your Kobalt air compressor won’t build pressure are:
- Failing intake valve
- Failing pump pressure valve
- Gasket failure
- Piston seal failure
- Compromised tank check valve
Here are some clues on how to look out for these possible reasons:
Kobalt Air Compressor Intake Valve Failing
If the intake valve has failed then the compressor will draw air in on one cycle, and then the air will blow right back out of the intake valve.
Kobalt Air Compressor Pump Pressure Valve Failing
In this case, air will flow into the tank through the pressure valve on the compression stroke but then be drawn right back out of the tank as the piston cycle to try and draw more air in through the intake valve.
Kobalt Air Compressor Gasket Failure
The flow path of the intake air inside the pump head is often only separated from the flow path of the pressurized air to the tank by a gasket. It is possible that your compressor is working fine, but as it is cycling, the air is flowing back and forth across a failed gasket inside the pump instead of being forced into the tank.
Kobalt Air Compressor Piston Seal Failure
The pumps will lose pressure and compression strength if the piston rings are defective. This can also reduce the pump’s efficiency to optimize the production of compressed air.
Kobalt Air Compressor Tank Check Valve is Compromised
The discharge head of the pump will receive a high pressure of air if the tank check valve becomes defective. It will affect the pump’s motor might and stop it from restarting anytime the tank is full.
Please visit our Why An Air Compressor Won’t Build Pressure & How To Fix A Compressor Not Building Pressure guide for detailed information on each, along with how to conduct the necessary checks!
Reader Questions & Responses
Kobalt Air Compressor Won’t Build Pressure – Kobalt Air Compressor Troubleshooting
Question
I’ve followed the instructions to set the desired PSI for my bike tire, when I press the Run/Pause button – it only runs about 3 seconds then shuts off – never reaching the target PSI.
My current PSI is 12 and desired to set it at 50.
I have to keep resetting and pressing the Run button, only gaining about 3 psi with each repeated cycle.
The unit is 10 months old and hardly used. Thanks
Response
So, you’ve seen the thing work in the previous ten months?
Have you tried it with the other power source?
What happens if you leave the tire/hose connection disconnected? Does it keep pumping, or quit that way as well?
I take it you got no help from Kobalt/Lowe’s or wherever you bought it?
Question
Yesterday, I tried to use my Kobalt inflator, but the “decrease PSI” digital setting no longer works.
Symptoms: I no longer can lower the desired PSI pressure I want. I press the lower rubber button, but the indicated desired PSI reading stays the same. I can raise the desired PSI pressure okay. Also, the blue LED light does not seem to be as bright as before.
Can someone help me? I’ve had this for about 5 years and it has worked really well. Thanks, Ben
Response
This really should have its own thread, but since the original questioner hasn’t come back with any response to their question, here goes on yours.
From general experience, I can say there’s a good chance the control panel is mostly glued together.
So, try to open the thing up and see if that’s the case. That’s one thing that can cause buttons not to work, and lamps to look dim.
The other thing is the power supply going bad. Switching to the other power source may make a difference. Have you tried that? Any difference?
Also, if you can get a pic or two of the thing, we may be able to suggest more things to check – as right now, we don’t really know what’s in it.
Let us know. Good luck.
Kobalt Compressor Runs But Will Not Build Pressure – Kobalt Air Compressor Troubleshooting
Question
Runs for 5 seconds then cuts off…then every once in a while it will hit for a second or two.
Response
Hi Cal:
A bit more information, if you could.
What’s the pressure in the tank? When the compressor runs for a few seconds, is the tank empty, or is it at full pressure?
What do you mean that it will “hit for a second or two”? Does this mean that it starts and runs for two seconds then stops?
When it stops, does it “unload”?
Maybe we can figure it out if you can give me more info.
If you have any questions about Kobalt air compressor not building pressure, please leave a comment below, with a photo if applicable, so that someone can help you!
I have a Kobalt #KL12120. It is older model that worked great so far. Last year, all of a sudden it stopped to work with 120 volts. When I plug it in, I still ge the display and the motor is running but not air is blowing from the compressor. However, the 12 volt input is still working great and I can inflate all my tires with the 12 volt connection. I have a RAM truck that needs 80 PSI. I am running the car’s engine when I am using it and it works great. But I am missing the… Read more »
(I’m gonna make some guesses here)
Sounds like it actually has two motors, one for each voltage.
There’s likely a broken shaft or linkage on the 120V one.
Maybe you can fix is, but you probably won’t be able to get any parts for it.
That’s if you can even get it open…
Let us know…please.
Thanks.It is very hard to open this thing. There are many screws hidden in holes. I could try to open it by force but I am afraid of breaking the working 12 v part in the process. As one can imagine this happened to me in the past! So, I think I will continue to use it until it dies or I get a Christmas present in some future year. Ha ha ha.
Maybe you could break the case after it dies just to see what’s in there…
I have the Kobalt KL12120 12V/120V Inflator. There is the regular sound but no air was going into the tire. I opened it up to check the hose for leakage. I didn’t see any. I feel the air inside on the left of the hose but nothing in the hose. What can be done? Can I do it? Must I take it somewhere or send it to be fixed? do I need to get a new one (Kobalt #0791911)?
Some people have tried, but AFAIK no one has been able to fix one of these.
As the manual shows only “loseable” parts I’m afraid there aren’t any and it’s not worth fixing.
You could go to their website, but they aren’t interested in fixing anything, and the bot is worthless.
Sorry. Of course you’re welcome to try to be the first to make a fix!
Good luck, Sorry.
I was inflating my tires with my Kobalt 120v dual inflator. And in the middle of pumping the noise from the pump raises in pitch. And since then the air pressure will not raise, its keeping the tire inflated. As in not losing ground, but it’s not getting up to the desired pressure either. I have yet to take it apart, it may have a split hose in side the unit
Just wondering if this inflator could push enough air to air up all four tires to 30psi at the same time. I do some off roading and airing up one tire at a time take about an hour. I have built a system that connects all four tires to one valve and just wonder if this pump could handle it? Thanks.
To 30psi from what? Regardless, the limiting factor is how long the pump needs to run. It can do it, eventually, if you don’t overwork it. The manual does not address duty cycle (how long it can run before it should get a rest, and how long that rest should be). Given what it appears to be, I wouldn’t run it any longer than you have in the past – maybe 5 minutes? And then let it rest for 5. Almost all consumer products like this have 50-50 duty cycle, and short continuous run times. So, go ahead and try… Read more »
Thanks for the input, I’ll try it at home first and let you know how it goes, thanks again
Just bought lobalt tire inflator. It stops inflating at 94 psi. I need 105 psi.
If you have what I suspect you have:
If new and it’s rated for at least 105, take it back.
If it’s out of warranty, you can try to get them to fix it, but they won’t likely be able to.
But maybe it’s something else, so how ’bout giving a model number or even a pic or three of it?
On the road right now ..the compressor is rated to 120 psi.will send more info and pics when I return home. I was putting air in my motor home tires and the first tire went well up until 95 psi It now won’t pump air and sounds like a vacuum. Thanks for answering so quickly. Jim
Yeah, I think that’s for like bike tires. Not truck tires.
Any idea how long it ran? Seems like a couple minutes is about all it’s good for (again, if it’s what I suspect it is).
My ac adapter works but my DC turns in unit but does give air.. did I burn something out?
Or is there a re set I can perform
“My ac adapter works but my DC turns in unit but does give air.. ”
HUH? You mean it works on AC but does not make air on DC?
“is there a re set I can perform”
Not that we’ve heard of. Read the other posts.
Feel free to mess around with yours to see if you can figure something out. If you do, let us know, eh?
I have same problems as Cindy above. I set target pressure. Putting the connector onto the bike tire shows existing pressure then when I turn it on, it quits after a second or two well below the target pressure. I ended up totally deflating my bike tire through repeated attempts to get it to work (I know the definition of insanity. . .). Also, if it is disconnected, it runs and puts out air, but if I even block the flow of air (supply resistance) with my hand, it quits. It’s like any resistance makes it think it has reached… Read more »
Yeah, seems like it’s a POS, or maybe just a QC problem. I’d still like to see some pix of the guts. Probably doesn’t matter, as no one seems to have parts for it.
So. Either buy another one, or buy a more conventional manual one.
The auto feature is really nice, and I almost bought one myself, but it’s just not worth the hassle, IMO.
Sorry.
The inflator no longer provides air. It sounds like it is just spinning inside and not compressing air.
It’s no doubt oil-less, which means some sort of plastic ring on the piston, which is shot/torn/broken.
Good luck if you want to try to fix it.
That’s why I’m here. To see if anyone talks about gut fixes. I was prepared to just throw it out, but I had to look to see if thee was a place to buy spares and anybody talking about the process.
I was blowing up a boat trailer tire and it the chugging stopped for a split second, heard a bang and then it was free wheeling.
Bear in mind I have no specific knowledge of the guts of these things, and as you probably know there are no parts for it to speak of.
Still, your description suggests maybe a shoulder screw or bolt used as crank bearing came off. All I can say is tear it down and see.
If you decide to do that, please post some pix of what’s in there.
Thanks and good luck.
I’ll take a look. I can’t possibly hurt it.
My KLDP1 will not start, registers feed back pressure but can not set desired pressure.
After owning mine for about 4 months it cannot pump anything up. It runs but it cannot even pump up a basketball anymore.
I haven’t seen the guts of one of these, but if the motor is going (and the sound the same as when it worked) it’s any of a broken tube, bad valves or piston ring. If the sound is much different, then it could be the drive from the motor to the pump broke.
So, all I can say is try to get it apart and look for stuff that’s broken. You may have to tear the pump apart if it’s not a broken tube or manifold.
If you get the cover(s) off, fee free to send pix of it…
Hi. I have a Kobalt inflator and when I plug it in, the indicator has a 26.0 reading (it’s the reading above the Target PSI) even though I have not used it yet to inflate my car’s tire. How do you calibrate it to zero reading ?
A model number might help, but in general, those things have “no user serviceable parts inside”. If it’s in warranty, take it back.
If that’s infeasible, you could look for a potentiometer near where the pressure sensor comes into the board. Note where it is, and tweak it a bit while monitoring the gauge. If it changes, see if you can get it to zero. If not, chuck it – in accordance with local hazmat waste disposal requirements, of course.
Good luck.
Thank you for your kind reply. Enclosed/attached is the model number and a screen shot of the digital indicator once I plug it without even inflating a tire
Lito, I see there is a manufacturer (wholesaler) number on the label. If you contacted them, what did they say?
I have the same issue, regardless of the power source(120v or 12v)with a unit less than 18 mos old and rarely used. When plugged in, it shows 22lbs of pressure. I have to set the pressure to 52 to get 30lbs in my tires. Calls to kobalt were useless. They said bring it back to lowes.
At least you have a work-around.
Have you asked about taking it back? Maybe they’ll give you a new one (or fix) for free, Or cheap. Or not…
I returned it to Lowes with original sales slip from Oct of 18, and they agreed to a one time swap for a new one. Kobalt is their house tool brand so I can see why they would. It’s smart customer service.
Right. We’ll be interested to know if this one holds up. They don’t seem amenable to fixing, but we haven’t all that many complaints about them, so don’t know what the failure rate might be…
Thanks for letting us know your experience so far.
No air is coming out of my Kobalt Inflator. What could it be? Help please!
Please have a look at the troubleshooting page about compressors with this problem. After doing some checks, please comment. Is this a new issue when using the Inflator the same way?
Own a dual voltage Kobalt Portable Compress. Have truck tires reading 60 psi. Want to inflate them to 75 psi. One tire completed. Started second tire. Sounds as if electric motor has disconnected from compressor? Sounds like a vacuum sweeper. Running on 120 volts?
Sounds similar to what I just experienced. Inflated one tire to 90psi, but failed on the other tire. I heard a pop and hissing sound of air, which stopped when I disconnected the inflator hose. Lower display showed 90 but the top was 0. Same display on other tires.
Just to rule it out:
Did you run it for less than ten minutes before giving it a ten minute rest?
Longer than that is bad for these.
Is yours a Kobalt #0146781 or something else?
You got to be kidding me! Run for 10 then rest for 10? What happens if you don’t “rest” it? You sure as heck won’t ever get a set of truck tires pumped up. They shouldn’t even sell these POS.
Sorry, not. From page 4 of the manual: This inflator is designed to inflate car tires, bike tires, ATV tires, sports equipment, air mattresses, beach toys and other inflatables. Do not use for any purpose other than inflating. If you do so, bodily harm or personal injury can occur. CAUTION: Allow inflator to cool down 10 minutes after each 10 minutes of continuous operation. Notice the absence of truck tires, although if you can top ’em off in <10, it should be good. And I do agree they should not sell these things. At least not without a bold face… Read more »