How to fix your 12v air compressor

Lightning knocked out my computer so I will try this again. 

I found a broken Campbell-Hausfield 12V air compressor while riding a motorcycle in the desert. I am financially impaired so when I find something, I take it home and try to fix it. I have been using this compressor for years, now. (About 7) and have used it for everything from patching and filling tubes to seating beads on my motorcycle. 

It is getting a little worn out, requiring a shot of oil to get up to 40 PSI. God provides-I just received a broken "Maxx Power" air compressor!

I will show you the basic steps needed to get one going again. 

P.S. the main image is what the Campbell-Hausfield compressor looks like today, after 7 years of often hard use. If I had the ability to buy a (Good) new one I would! But they can last. 

Step 1 First off, take it apart (Phillips head screwdriver)

In the second picture I say to oil the bearings-wait until you remove the motor. 

Inside is a very simple mechanical assembly. 

A motor turns a gear that is connected to a crankshaft.

The crankshaft is supported by two bushings, and has a shaft that is connected to the connecting rod.

The connecting rod is connected to the piston, which moves up and down in a polished metal cylinder.

While the piston is traveling down, a one-way reed valve allows air to be drawn in through a small hole on top of the cylinder head.

While the piston is traveling upwards, the pressure closes the one-way reed valve, and pressure builds up until it is pushed through the one-way valve that is connected to the gauge, and output barb, travelling to the chuck. 

9 times out of 10, with inexpensive 12V compressors, the entire assembly simply lifts out. 

Comments

[Phil B]

Thank you for your Instructable. I use these compressors to air up bicycle tires on bikes I leave in other cities. I power the compressors from a rental car. One compressor is rather cheap and the motor just does not have what is needed to power the compressor. I am thinking of removing the motor and fitting it to an electric drill.

[tundrawolf]

Thank you for your kind words. I understand your problem with the pump not working up to par. However, if you take the assembly apart you will see that the motor is spinning the driven gear faster than a drill motor. The DC motors they use are high RPM high torque and are usually of fairly high quality.

I can say with certainty that if you follow my instructable and grease your pump entirely, and especially grease the piston and cylinder, your pump will work better than it ever did, even when new.

Even adding a drop or two of oil in the intake (On top of the cylinder head, you will see a hole) will dramatically increase compression and performance.