When most managers walk around their shop they are like the title of the movie, “Eyes Wide Shut.” They just walk by the most obvious tiger tails of woes. Take, for example, the infamous coolant bucket, half filled, and 55-gal. drums that clutter the shop.
I always ask the question, “Do you use a lot of coolant?”, and the answer is always, “No more than usual.” About the same time a driver walks by asking for a gallon to take with him.
Then I ask, “Do you pressure test the cooling system?” The answer most often is “Yes, I think so.” When I ask to what pressure, most often the answer is “I‘m not sure. I’ll have to check with the supervisor.” Then the supervisor says, “I’m not sure what the tech does.”
Really curious now, I have to ask the tech if he pressure tests the coolant system. The usual answer: “Sometimes when there is a leak, or a complaint of coolant usage.”
I continue to go down the path and ask what pressure do you pressure to? Most often the answer is “Whatever the cap pressure is.”
“Do you test the cap?” The answer always is “Not really, unless the cap is leaking.”
Tired of reading yet?
When I ask to see the tester, the tech goes to find it, comes back and says, “I can’t find it. It must be out getting fixed because it was broke anyways.”
If I then get into a conversation about pressure testing to 18-20 lbs., then the gloves come off. “You can’t do that, you’ll blow the radiator. You’ll blow a heater core or the plastic tank off the radiator.” My answer is always, “Good, let it blow here in the shop.”
Then comes the Eyes Wide Shut comment: “Do you know how many leaks you will find at 18 lbs.?” My answer is “Yes I do!”
The coolant system has become more important than ever before. Before it was just a leak, one that evaporated as the truck ran down the road, a small leak that was never seen except during cold weather. We called them cold water leaks. We just kept buckets around to “top off” the system. But it’s a closed system. It should not leak and if properly maintained, using or topping off with coolant should be a procedure of the past.
The water pump pushes coolant around at 25 lbs. plus of water flow pressure, the cap creates the pressure to raise the boiling point of the coolant for proper engine temperature to helping to achieve maximum fuel economy. Most systems today are designed to run to exceed 18-20 lbs. with an 18-20 lb. cap. If you’re losing coolant, proper pressure testing will expose any external coolant seeping or leaking before winter. And if it isn’t leaking externally after 5-10 minutes of 20 lbs. of pressure, then the leak is internal. If it is internal, then that might be the first sign an EGR cooler is leaking internally and it will show up weeks before the oil analysis report comes back. Maybe this simple test will quickly solve a lot of DFP issues that are upstream or low-coolant fault codes.
The point is you may want to ask the same questions I ask. You may be surprised. Most PM sheets never quantify the pressure to check it at so techs do what they want or believe it should be. That’s often the cap pressure, and most new caps fail right out of the box. You may also find out your tester is broke, or you have none. There are many types and styles, and different brand, all good, but the one style I like is pressured by shop air and regulated to 18-20 lbs.
I would suggest being as adamant about pressure testing to 18-20 lbs. as you maybe are about oil analysis. You may find that leaking EGR cooler ahead of its time, or just in time, or reduce fault codes and reduce coolant usage. My friends at PEAK like selling coolant but prefer we do a better job of maintenance. Just ask them.