A few weeks ago, I noticed that my air compressor wasn’t recovering as fast as it should. It’s a two-cylinder, single-stage model and one of the cylinders was actually blowing air out of the intake instead of sucking air in. Since it was still operational, I made a note to myself to call the service department to about fixing it — I didn’t actually get around to it until yesterday.
When I called the service department and navigated the phone tree I got a friendly representative — let’s call him Bob — I explained my problem to him and said that it should still be under warranty. Then he asked if I had the ability to take the cylinder head apart myself and look for the cause, they would replace any parts that I broke in the process for free — except he said to be careful to try to save the gaskets because they were on backorder. He said it was more than likely debris in the head or a loose part. This surprised the heck out of me. I hadn’t taken it apart yet because I was afraid that if I so much as looked at it funny, they would void my warranty. Here Bob is telling me to take it apart myself and they would replace anything I broke in the process!
So I unplugged my air compressor and removed the head on the faulty cylinder. As I removed it, a few drips of rusty water fell to the floor and I though that I had found my problem, but I took the rest of the head apart anyway — careful not to destroy the gaskets — and found no other issues. When I tried to remove the top valve, I ran into a problem, a 2.5mm hex wrench was too small and a 3mm was to big. The rest of the pump was metric, but I tried my Imperial hex wrenches anyway and nothing fit. Is there a 2.75mm Allen wrench? I managed to remove the screws using the 2.5mm wrench and a plastic bag — which was just enough to give the hex wrench bite.
Once the valve was off, I cleaned it and the cylinder head, put the head back together, and fired up the compressor. It actually worked! Since this was the second in the air line to the tank, I’m not exactly sure if the water was what caused the problem or if the other cylinder head was pumping it in.