Luckily, replacing the regulator is an easy job, and can be completed in less that half an hour.
Step 1: Materials and Tools
1/4 inch Mini Regulator - under $20. Most hardware stores should have one of these in stock.
Adjustable Wrench - for turning stuff
3/16 Allen wrench - for turning other stuff
Scrubbing pad - for scrubbing stuff
I didn't take a pic of the tools needed, I figure most folks know what we're dealing with here.
Step 2: Remove Old Regulator
I placed the wrench around the body of the old regulator to get it off, as I couldn't turn it by hand. As soon as I applied pressure the entire regulator fell to pieces. After that everything came off easily. You'll want to save the female quick connect to use on the new regulator, if it's still in good shape.
I also saved the gauge. The new regulator came with one, so now I have a spare for another project. Sweet!
Step 3: Prepare for New Regulator Installation
Then use the teflon tape on the threads. Be sure to apply the tape in the direction of the threads, else the tape may come off as you thread on the new regulator. Also, you'll want to avoid covering the end of the fitting. Doing so will restrict air flow and lead to decreased performance.
Step 4: Install New Regulator
So I guessed. Looking into the regulator I could see some workings on one side, and just space on the other. I figured the side with the workings should attach to the compressor, the other side to the hose. Turns out I was right. Yay!
Simply thread the regulator onto the fitting. The power cable and a hose got in the way when I was threading the regulator on, but I was able to move everything enough to get by. Just barely. If your compressor is more compact you may have to remove additional pieces to be able to get the new regulator on.
Decide which side you want the gauge on and screw it in, after taping the threads. Then install a plug on the opposite side. Two plugs came with the regulator and they already have a sealant on them. You will need the allen wrench to install the plug. The instructions mention an included wrench, but I found none with mine.
Lastly install the female quick connect you saved from the old regulator. Now fire up the compressor and check for any leaks. If you find none, hook up a gun and go to town. You're done!.
Step 5: Troubleshooting and Conclusions
If you do hear a leak there are a few things you can do. The first step is to find the source of the leak. I've found the running my fingers over and around the fittings and ports is the easiest way to find leaks. You won't be looking to feel a leak so much as listening for a change in pitch.
When you find the leak try tightening, or re-installing the fitting. If you try re-installing remember to replace the teflon tape. Another option is to try another port. For example, I found that the gauge included with the new regulator would not fit into one of the ports, so I had to swap it to the other. This is why the finished pic shows the gauge in a different orientation than the assembly pic.
You can also try swapping out the fitting altogether. I found that the female quick connect was shot to begin with. Instead of replacing it my father simply tried duct taping it. In this case replacing the fitting was the better option.
Lastly, you can choose to ignore it. A small leak isn't that big a deal in my mind.
This was really a very easy fix. I went in thinking it would be much worse. Of course, different models of compressors may present more or fewer hurdles. It seems many newer pancake compressors have a good deal of plastic covering everything, so some radical surgery may be required to get to the important bits.