A Cool Trick for Working On AC Systems

Last week was Mechanic Week for me. I knew I was going to put a new clutch in my wife’s little car, but I was also provided the surprise opportunity to replace the locked up AC compressor on Red Truck. With about 200k miles, I am kind of proud that it made it this long.

Everything is really easy to get to and the truck has high mileage, so I decided to do it right: new compressor, flush everything, new dryer, new orifice tube, pull vacuum for an hour, etc. With everything out in the open, I figured I might as well. I was able to replace the compressor and dryer in about 30 minutes. Then I got the orifice tube.

If you are not familiar with AC systems, the orifice tube is a small nozzle that allows the freon to expand from liquid to gas. Cooled gaseous freon subsequently goes through a heat exchanger to cool the car. The orifice tube is a small 1-piece device that simply slides into the high side freon tube before the evaporator. The orifice tube has an integral tang at the top for easy removal. Pull on the integral tang, and the whole device slides out of the freon tube. It would make sense to place that tang near the opening of said freon tube. Ford thought otherwise (shown to the right).

It turns out that needle nose pliers can be modified to reach the tang of the orifice tube. Modified needle nose pliers are very good for un-integral-ing the integral tang from the 1-piece orifice tube, leaving nothing to grab. Luckily, Al Gore loaned me his internet so that I could find a solution.

This seems to be a fairly common problem. I found that the “old guys” get a long wood screw, wrap tape around it as a guide, screw it into the top of the orifice tube, and yank on it with unmodified pliers and all of their might. Despite Ford’s best efforts, I had it out in minutes. Does this mean I am now an “old guy”?

While I am talking about Ford A/C systems, I would like to complain about something else they did. Some engineer somewhere decided to use a rubber ball instead of a shrader valve on their high side service ports. It might have saved a penny at some point, but I’ve never met one that didn’t leak. I’ve also met very few high side couplings that will reliably press the rubber ball enough to get a consistent reading. Why, Ford? Why?

Pulling all of this together, I wish someone would take Ford’s high side service port design and shove it up the engineer’s orifice tube. Also, try using a wood screw and some tape to remove your orifice tube if you (or it) are in a bind.

 

Needless to say, the gallant steed is all back together and on the road. Hopefully the AC system in Red Truck will keep together for another 200k miles.

Let’s Mix Things Up

KIMG0063For some reason, I have been fascinated with KitchenAid mixers since I was a little kid. I think it is because my parents had a large Hobart mixer at their restaurant, and I thought the smaller home edition was novel. Or more likely, they have gears, mechanical attachments, and a motor… three of the things that are dearest to my heart.

I bought one a while ago from Craigslist, and it leaked oil the first time we tried to use it. After getting over the initial horror of oil dripping into the dip we were concocting, I read up and found out this problem is fairly common. KIMG0064The grease they used breaks down over time and becomes a combination of a cakey substance and a fairly thin oil which drips from the case. I disassembled it, replaced the grease with Food Grade Machinery Grease, and all was good. This was about a year ago, and there has not been another drop of oil.

Tonight I was at a good friend’s house, and she mentioned she was having the same problem. She was even thinking about getting a new KitchenAid. I brought it home, did the same procedure, and it is now as good as new. I am posting this as a public service announcement. Don’t throw out your KitchenAid mixer if it drips oil! It is a fairly simple fix.KIMG0065

I included some pictures of the inside in case you’re curious. I know that I was. I didn’t include a picture, but it also has an interesting electromechanical governor system that adjusts the power delivered to the motor to maintain the selected speed under varying load conditions.

A couple more things:

  • Yes, the pictured mixer is purple.
  • No, it is not mine. Mine is much more masculine.