Central Pneumatic Model 67501

Published Categorized as Central Pneumatic 27 Comments on Central Pneumatic Model 67501

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The Central Pneumatic model 67501 air compressor is one of Harbor Freight’s popular air compressor models.

As I look at the features of the Central Pneumatic model 67501, I can’t help comparing it to one of the air compressors in my workshop. Mine is a dead ringer for the 67501 if you simply remove the Harbor Freight / Central Pneumatic decals and replace them with another brand name. I suspect the same factory in an Asian country supplies this model of air compressor to big box stores all over the world.

With a 2 HP motor and an 8 gallon tank, the model 67501 provides enough air for short-burst air tools, but no where near enough to try to run grinders, sanders, air-blasting equipment. I use my similar model for blowing off the workbench, table saw and planer, driving some brad-nailers, and airing up tires of course.

The 67501 air compressor is useful anywhere that the 125 PSI that is available from this Central Pneumatic air compressor, in a relatively low flow, can do the job.

Central Pneumatic / Harbor Freight model 67501 air compressor
Central Pneumatic / Harbor Freight model 67501 air compressor

In late 2013 this model is still available to be purchased from Harbor Freight. This means that parts and some support should be available from them.

Central Pneumatic 67501 air compressor manual available to download here:

There appears to be enough interest in the Central Pneumatic 67501 air compressor to have a page specific to this model on this site to help folks looking for information and help with their compressors, and a place for present users to offer assistance to others with the same air compressor.

Please use the form below to post your own question about the 67501 air compressor from Central Pneumatic (Harbor Freight). Only questions relating to this model can be posted on this page, please.

If you own a 67501 and see a question you can help with, please add a comment to that post. I appreciate it as do the many 67501 compressor owners and users that may have a similar issue with their machines.



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I have a Central Pneumatic 67501 air compressor. A while back it blew the oil fill plug out. I replaced it with a 1/4″ pipe plug. Then a couple days ago it blew the oil level sight glass out. I am thinking there should be a crank case vent but can’t find one. Does anyone know if there is a crank case vent on these compressors and where it is located?Thank You

I checked another compressor like mine and see the vent is suppose to be in the fill plug that blew out of my compressor and was lost. I am going to drill a vent hole in the pipe plug that I installed in the oil fill hole and hope that takes care of my problem.

Where can I order a replacement capacitor for model 67501 central pneumatic compressor

Somewhere on the internet or maybe your local Grainger or motor repair shop.

Is it a cbb65a? 130mfd? 250Volts (or more?)
That’s what you look for, or whatever is marked on it.

Good luck.

I have this unit, replaced the cold start valve, replaced the start capacitor, and inspected reed valves. It tried to start for 3-4 seconds, and then shut off. Anyone have any other ideas on troubleshooting?

Yeah. You’re taking restart? When it stops,

  1. Does the tank hold air?
  2. Is the cold start valve open (the button thing *not* up)?
Last edited 2 years ago by Doug in s.d.ca

Doug, when the pop up attempts to stay closed (up) for a brief micro second or so, then falls. The rest of the unit works fine, holds air etc. I tested by removing the cold start (unloader) for a few seconds, then screwing it in. The compressor then works normally. BTW this was a new valve. I am purchasing another. But is it continues to fail I am not sure how to repair.

OK – You indicated this is a 67501.
If it has a cold start valve, it’s something else.
Please send correct model number and/or pix of the area of the pressure switch and check valve.


Hi again, it is a model 68740, I had grabbed to model from a Google search based on the look of the unit. I have also checked the reed valves, and replaced the start capacitor with one I bought from a compressor place online, the cap value was same voltage and uf values. I don’t have a pic of that. Again, it starts if I leave this valve off and then screw it in after it starts. It reached full pressure and shut off as it should. Any advice is appreciated. G

Alright then.

That valve is there to assist in minimizing the pressure the pump has to overcome when it is starting. If the button is down, that indicates little or no pressure against the piston. When it comes up it just means the pump is starting.
So I ask: when the pump stops at cut-out, does the valve button drop immediately? It should.

I’m going to stop at that, pending your response.

Last edited 2 years ago by Doug in s.d.ca

The only way it will start is when I remove the valve, for a few seconds, then quickly I screw it in, it runs up and holds pressure and the valve drops

I’m sorry.
I can’t help you if you don’t precisely answer my exact questions.

Good luck.

Yes it drops immediately.

Thank you.
That means the unloader in the pressure switch is working.
Also, you’ve said the tank holds air after the pump stops. That means the check valve is OK if so.
Which brings us back to the start capacitor, if that’s what it is.
So, first, what is the rating on the capacitor? A pic of the whole thing with the ratings showing would be ideal.
Second, do you have a volt-ohm-meter? If not, please buy or borrow one. It can be cheapie, so long as it does ohms.

Last edited 2 years ago by Doug in s.d.ca

Hello Doug, Yes I have numerous Volt Ohm meters, a few modern digital and an older Triplett. I have attached pictures.


Excellent. It is a start cap. I assume you know how to use your meter. Did you test and find the original was bad? Or at least “iffy”? I think either the start winding is bad or if you’re lucky, the centrifugal switch is dirty/bad. To check, see if you have DC continuity from one terminal of the cap to either prong of the power cord (obviously unplugged, but “turned on” at the switch, tank pressure below cut-in). You should also have continuity from the other cap terminal to the other prong of the power cord. Finally, measuring across the… Read more »

Sorry for the late reply, been real busy. As it turns out the cold start valve is acting strange. When I recorded the results that I last reported, I probably should have tried a few times to ensure the result. The valve pops up, when I turn on the unit. But it falls too soon and the compressor struggles to start. When I use a tool to hold the valve up. the thing starts up. and the valve drops. I purchased a brand-new valve and it stays up and does not drop.

That totally does not make sense.
Would you send pix of the replaced valve, top and bottom up views, please?

Hi Doug, here is what I had (lower pic) and currently have installed (upper pic).

Is it a fix?
And I wanted to see see pix of *your existing* (original) valve.

Sorry for the late response. None of the valves work. The original I lost in a recent move. However, these 2 replacements according to my research should have worked. Here are pics of the first replacement and the one I just bought few weeks ago.

Did you ever do the checks I suggested June 27th? It seems you are misunderstanding the purpose of the cold start valve. When the compressor is actually cold, it provides an extra time for the motor to get started – it does this by staying open until the pump reaches some low pressure, indicating the motor is running. The valve then closes, and is *supposed to* STAY closed, so cut-out pressure can be reached. That yours closes and reopens just says the motor is starting and then stalling. And that is where the start capacitor checks I suggested come in.… Read more »

Last edited 2 years ago by Doug in s.d.ca

Doug, I will try the steps mentioned on 6-27 and let you know what I find.

Doug, sorry for such a late response, had some medical things to attend to. I performed the continuity tests mentioned on 6-27 last night. -yes there is DC continuity from one terminal of the cap to either prong of the power cord. -also there is continuity from the other cap terminal to the other prong of the power cord. -measuring across the cap terminals I see a small reading as you mentioned. I reinserted my new cold start valve, and the compressor spun up. I turned it off when the pressure seemed to not stop, and it was surpassing 120psi… Read more »

Sorry about the medical – hope it turned out OK. Quite possibly it is now working. You may have cured a bad connection or two at the cap when you made your measurements. If it has the usual push-on clips, you might wiggle them a bit to see if anything falls off. If not, re-test. BTW, if it doesn’t cut out right at 120, give it time to get up to 135. During that time it should either stop on its own or blow the PRV safety. If the PRV blows, you’ll have to turn it off manually, Those are… Read more »

Doug, With your help, this old compressor is now working well. I appreciate your help, have a Great Holiday Season, and a Safe and HEALTHY 2021.

Back atcha. ?
You’re welcome.