Tech Tip: The final winner

Jan. 1, 2020
Those pesky little leaks can be caused by a tiny fragment of debris trapped in the valve, worn valve seats or even from a sticking valve we inadvertently leave leaking when we disconnect our equipment. Here's a tip on A/C fittings.
Paul Stock has been in the automotive business for a long time, starting after his graduation from Bailey Technical School in 1974. He has owned Stocks Underhood Specialists Inc., in Belleville, Ill., for the last 27 years. He is ASE CMAT with L1 certified, holds an AMI degree in Automotive Management and is a CAAT certified trainer. April is our air conditioning issue, and also is the last month for our tech tip contest. So, it's fitting that we end this contest with a tip on fittings. A/C fittings, that is. Those pesky little leaks can be caused by a tiny fragment of debris trapped in the valve, worn valve seats or even from a sticking valve we inadvertently leave leaking when we disconnect our equipment. Some loss here is normal; that's why they have caps. But excessive leakage will have your customer back in short order, a little hot under the collar, and not because it's warm outside!

Paul Stock, of Stock's Underhood Specialists, Inc. in Belleville, Ill., shares this tip on testing the A/C system fittings before and after you perform A/C service on your customers' cars.

"When air conditioning jobs come in, we have a tendency to hook up our equipment to verify that it is indeed low (on refrigerant). We then begin the task of finding the leak. Many times the leak is the port we just sealed with our equipment. We attach a vacuum gauge to each port before and after the hook up to see if the port is leaking. It gives us a visual indicator as to how bad the leak is and we aren't fooled by the traces of refrigerant that the sniffer picks up."

Attach a vacuum gauge to the test ports and wait a minute or two. Pressure build-up on the gauge indicates the port is leaking. (Photo: Paul Stock)

Not a bad idea, Paul. Thanks for taking the time to share, and congratulations on being this month's winner.

HONORABLE MENTIONS

Glow Plug Test Tip

If you have a short glow plug on light or the controller cycles quickly, the problem is most likely the glow plug. When testing diesel glow plugs, you can ohm test them but you may get false readings. The best way to test is to remove the glow plug, set it on a non-metallic surface, and then recheck the resistance while not touching the plug with your hands. If it passes this check, move to the power test. Hook ground clamp to the glow plug body and touch a 12v power to the end for a count until the tip turns red. It must be the tip (not on the side or at the top near screws). Test all plugs to make sure the count times are close to one another and replace any that don't pass these checks. New plugs also should be tested. Don't assume new ones will be good.

John Ryan, Indiana

Be a Professional

If you want to be treated like a professional, be sure you act like one. Strive to do the job you're given right the first time, and give your customer and your employer the full benefit of your training and experience.

Think of the impact we could have on this industry if we all followed Denny's advice!

Denny Alvarez, Florida

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