Introduction: Hacking Your Air Compressor for Fast Fill Up

Picture of Hacking Your Air Compressor for Fast Fill Up

My cheap air compressor was taking a long time to pump up. So I investigated and found some strange things that impede air flow. This Instructable will show you how to make your air compressor pump up faster. This particular air compressor was purchased from harbor freight.

Step 1: The Original Air Filter Is a Muffler?

Picture of The Original Air Filter Is a Muffler?

So the original air filter has an indirect air path to the foam filter. This is to make it quieter. But its a loud air compressor. If you want more flow with out voiding your warranty just flip this cover over and air can come in from any direction.

Also in the third picture the highlighted area shows where the plastic was covering the air inlet. This was from super high quality Chinese manufacturing.

Step 2: The New Air Filter

Picture of The New Air Filter

I was looking at multiple solutions for a better air filter and I found this bad boy. Its total thickness is just a hair more than the original total setup.

Step 3: Tools Needed Step 1

Picture of Tools Needed Step 1

A Dremil with a cut off wheel, or any rotary cutting tool, an Exacto knife, and sandpaper.

First cut off the bottom bowl.

Step 4: Step 2 Grinding and Cutting

Picture of Step 2 Grinding and Cutting

now grind the rest of the material off until its flat. Sand the base flat as possible.

Also now you can use your exacto blade to remove the casting flaws that are blocking air flow. I highlighted the areas on mine that were clogged up with excess plastic.

Step 5: Asseble and Enjoy

Picture of Asseble and Enjoy

1. Screw in the original base

2. Install the base plate from the kit with the washer underneath.

3. Oil the foam, and install the cover.

4. Enjoy your new fast filling air compressor.


Lorraine Prather (author)2017-09-15

Really we got interesting and important information from this.

madpenguin8 (author)2014-08-15

Interesting information, there are a few things you should be aware of though as you may be running your equipment outside of it's design parameters. Typically compressors are designed to use the maximum power provided by it's driver (motor, engine, etc.). This is determined by the operating pressure and flow rate. Making a compressor run beyond these parameters will generally cause the driver to operate overloaded and result in drastically reduced lifetime. My suggestion would be to check the amp draw of the motor and compare it against the data on the motor tag. If this is not available then a baseline drawn from running the compressor before modification might help. You can do an amp draw using a clamp meter. You will want to check the amp draw once the unit is near it's cut-out pressure.

On the topic of noise, compressors like this are always noisy because of the speed at which the pump runs and also because reciprocating are inherently noisy. Reciprocating compressors consist of a piston, cylinder and pairs of check valves. In this unit it has reed valves which are little strips of spring steel that sit against a valve plate, as the piston moves up and down the reeds pop open and then snap shut, this is the origins of much of the noise. One way to reduce this is to relocate the inlet air filter. You will notice on your air filter assembly it looks to be standard 1/2" NPT pipe thread. If you plan to use your compressor without moving it you can move your inlet air filter assembly to the outside if this is practical. Simply run PVC pipe from the inlet to outside the nearest wall and thread your filter into that.

Hope this helps some of you, I have worked on industrial air compressors for over a decade and this is how we help reduce noise in equipment.

chapiz (author)2014-07-15

I find it amazing what can be done with an air compressor

zappenfusen (author)2013-12-31

Another Harbor Freight Nut! They opened in my home town 3 years ago and I love the place. Hacking there equipment is mostly a must due to as you say the High quality Chinese manufacturing. The new filter has got to beat the original in every way accepting a slight noise increase. They couldn't get much noisier though. Great idea! My wife as a Customs broker imports containers full of High Quality Chinese manufactured products so I can't complain too loudly but I must add that as businessmen they're really butterheads!

Hansj3 (author)2009-08-22

wow i have one of these... and it works great. how much faster does it fill, and where did you get the b&s; air filter kit?

bensmith8302 (author)Hansj32009-09-01

I bought the filter at home depot. It fills in about 5 minutes. It used to take what seemed like forever.

WayneEarl (author)bensmith83022013-10-03

so then, by "forever" are you saying you didn't take a baseline measurement? by definition, a functioning filter will always result in some air flow restriction due to it work as a filter - some mesh or other static material that will filter out things as a result of it's collision with moving air under pressure. this is partially why most air filter systems are supposed to be Very close to the drop where they will be used, and is also why it is good practice to have a pressure gage both before and after a filter - as the filter fills up and is used, it gradually increases pressure loss, and the manufacturer should tell you at what point the pressure loss means time for replacement. removing the filter will increase flow - until contaminants fly pass the filter less air intake and destroy your compressor motor, or you destroy painting targets or air tools with dirty air. I would suggest additional research on the topic - perhaps you have given poor advice here?

bensmith8302 (author)WayneEarl2013-10-08

My advice is to remove the stock piece of crap air filter. Then replace it with a better filter with more surface area. The stock filter consisted of a cheezy 1" foam disc. It would possibly stop a bug from flying in but hardly stop dust. So the lawnmower filter is a massive upgrade is filtering technology. And as a bonus is fills up faster. This is due to the muffler less design. It is a bit louder, but its worth it.

master key (author)bensmith83022013-11-08

did you oil the foam mower filter?

bensmith8302 (author)Hansj32013-10-08

home depot

Geetha shree (author)2013-04-13

It helps to know how to hack an Air Compressor's easily by us. Inner parts are clearly shown as see the equipment really.