The History of Automatic Transmission Fluids (ATF): Part 1 - Introduction

Honda 4 wire pressure switch

Oh Two For You

Antiseize compound is wonderful stuff, when it works. But when it doesn’t do its job, you’ve got problems! And so it was with this fitful last minute chore, which ran against everything I’ve been telling my customers for years and years.



Don’t wait until the last minute! Don’t bring in your car for a major service the day before you’re driving out west on vacation. There’s nothing worse than to install a brand new spark plug – or set of plug wires – and have it fail when my best customer is halfway across the Great Plains and in the middle of nowhere.



If a part is going to fail, you want to be around so you can do something about it. And anyone who has been in this business for awhile knows that even a brand new spark plug can be faulty and begin to misfire a day or two after you install it.



So that’s why I tell my customers to have their vehicle serviced a couple of weeks before taking off on a trip. “Give it time for everything to break in and mellow out before you leave,” I always say. Then why didn’t I listen to my own advice?



Here I find myself on Friday night, Memorial Day weekend ahead, leaving in the morning on a seven-hour trip, and I’m going to replace the oxygen sensor. It was long overdue for replacement, with over 160,000 miles on it. And with the price of gas breaking the bank, I decided to go ahead and bite the bullet and replace it.



I had been meaning to do it at work, where I could get the car up on a lift making the job much easier. But I had procrastinated until the last minute, and here I found myself having to do it in my home workshop, lying on a creeper under the car.



But, let me defend myself by saying that I had planned for the worst, and had my oxy-acetylene tanks freshly filled and ready to go for the extraction. I call it an extraction because the old sensor never wants to come out easily, and always needs assistance from the best nut buster of all times – the heat wrench.



I figured it would be a cakewalk. No big deal. No muss, no fuss. Easy pickings. Just heat up the sensor’s mounting flange until it’s cherry red hot and it’ll unscrew right out. After all, they installed it at the factory with antiseize compound, right?



Haw, Haw! What a joke. Sure, that slippery stuff is made to keep things from becoming stuck together, but after a dozen years it has turned to dust. Oh, don’t get me wrong. The sensor came out with nary a sweat. But when I held it in my glove, I saw the threads—or should I say what was left of the threads (see photo below).



The oxygen sensor has pulled out most of the threads with it, I didn’t have a heli-coil and the shop where I work was closed. We’re supposed to leave in the morning! Nothing like a little pressure to get the old mind racing. I rehearsed my speech to my wife, “Honey, I just broke the car so we have to rent a car for our trip!” Not! She would hand me my head!



I thought about running a tap in the hole to chase the threads. What threads? The threads would be so far gone that by the time I ran a tap through the hole, the new oxygen sensor’s threads would have practically nothing to bite into.

A vision ran across my mind of us driving along out in the middle of nowhere when the oxygen sensor blows out of its socket – POW! This would be immediately followed by the roar of the huge exhaust leak that was just created. My imagination continued the movie of us driving into the dark night with the exhaust roaring as we limped along.



I mumbled to myself, “It’s never easy.” Why is this always true? Why does Murphy’s Law always seem to rear its ugly head at the worst possible moment? And why me, why does it always happen to harmless me, me the good guy? I remembered my wife’s wise answer to this epic question, “God never puts more on your plate than you can handle.”



She’s right, I’m not defeated that easily. This old dog still had a trick or two up his sleeve. If the old oxygen sensor came out so easily with heat, maybe I could reverse the situation and use heat to get the new one back in. If I heated the flange up until it was red hot, it would expand. Right?



Then, while the flange is nice and hot and expanded, I could quickly spin the new oxygen sensor right down home in the flange socket. Then, when the flange cooled and shrunk, it would squeeze what was remaining of the threads nice and tight onto the new sensor. Right!



Well, it worked like a charm. That is, until the new sensor had screwed seven-eights of the way home, then it got hot and expanded and didn’t want to turn anymore. But I was determined. So I grabbed the heat wrench and once again heated the flange until it was cherry-red hot.



I worked as quickly as I could, laying under the car on my back with pieces of hot metal dust falling into my face. Grunt, grunt, groan. Creak, creak, the sensor let out a screech as it made its way home. I did it! The new sensor was in place firmly buried in the flange socket. And our vacation was not going to be ruined!



Then the doubt crept into my mind. “What if I ruined the sensor by heating up the flange?” And then I thought, “What if the new O2 sensor was defective right out of the box?” But, no. My mechanic’s nightmare had ended and everything was peachy-keen from then on. Our vacation was terrific!