Auto repair lessons learned in a minute

Aug. 1, 2019
Producing our "Mighty Minute" video series has taught me a lot. Let me share a few lessons I learned along the way!

As I write this, I'm in the process of producing our 20th "Mighty Minute" — a video tech series sponsored by our good friends at Mighty Auto Parts. Each video is limited to four minutes in length and those of you who know me, know that it has been a challenge to stay under that limit especially as I dive into each topic and learn more about it.

The neat thing about this series is the foundational content it is made of. We rarely, if ever, get into the advanced stuff here because the series is produced to help techs who are just getting their feet wet. They are also designed to help techs explain, in simple terms, why a recommended service or repair (related to that week's topic) is needed.

Along the way, I get the chance to interact and learn from experts in each topic. So far, I've produced videos (all of which can be seen on our Motor Age YouTube channel) covering serpentine belt service, cooling system service, brake service, A/C testing and leak detection and more. While I thought I knew enough to easily produce four minutes’ worth of video, the experience has shown me that I, even after 40+ years in the business, can still learn something new.

Allow me to share with you a few lessons I've learned. Who knows? You may learn something too!

The importance of the serpentine belt

I'm just as guilty as I think many of you are when it comes to checking the condition of the serpentine belt. I take a look to see if there are any visual indications of wear and maybe even give it a tug or poke to see how tight it feels. After that, and if it isn't making any noise, I'm done!

But I learned that the serp belt plays a vital role that I'd been overlooking. It is responsible for funneling power from the engine to all the accessory drives connected to it; the alternator, the power steering pump, the air conditioning compressor and sometimes, the water pump. Any slippage that occurs between the belt and its pulleys generates excessive heat and that can occur even if the belt is running quietly.

One of the least expensive tools you'll ever add to your tool box, the serp belt gauge is the best way to properly verify a belt's condition.

This excessive heat is passed on to these components - to their bearings, specifically - accelerating the wear and leading to premature failure. What's costlier? A new belt and tensioner or a new alternator or A/C compressor?

I also learned that belts made for the last 20+ years can be worn out yet show no visual signs of damage. The only correct way to inspect them is through the use of a belt gauge, a small plastic gauge that every major belt manufacturer makes a version of. If you don't have one, ask your parts house. I'm betting they have a whole box in the back!
 

With the tool square and perpendicular to the belt, you should see light between the gauge and the top of the belt ribs. The belt on the left (2A) is serviceable. The one on the right (2B) is not.

Clean air for the engine

Dirt is a major enemy of the engine. When you consider how small the clearances are on today's powerplants, even the smallest visible dirt particles can cause major wear and tear if allowed in. So how do you know when the air filter on your customer's car needs to be replaced?

The answer I got was surprisingly unsatisfying. Ford, on some of their vehicles, used an airflow gauge to help determine when the air filter was restricted to the point of requiring replacement. And the engineers I spoke with told me they determined replacement by using expensive scales to actually measure the weight of the filter. Not very practical for every day, in the shop, use!

They did agree, though, that a simple "drop test" can provide some indication of how dirty a filter is. Simply drop the filter from waist height onto a clean rag and if you see dirt on the rag, replace the filter. Of course, if you can see visually that the filter element is damaged, has gotten wet, or contaminated with blow-by, there's no need to do the "drop test!"

So far, nothing to new, right?

Would you replace this filter? Be sure to inspect the condition of its seal as well as the condition of its filter element before making that call.

I also learned that one commonly overlooked item is the condition of the filter's seal. Damaged or torn seals provide an alternate path for dirt to enter the engine. Additionally, warped or damaged air boxes can do the same thing, allowing dirt to bypass the filter element. If the box is damaged, replace it as well.

Clean air for the occupants

If the engine needs clean air to survive, how important is it for the vehicle's occupants to have clean air! Vehicles have been sealed tight for decades now to keep the road noise out but it also keeps the stale air in. Some estimates say that pollutants in the air of a typical automotive cabin can be 6x more concentrated than the air outside the vehicle!

And cabin filters need more frequent service, with most OEMs recommending service intervals of 15,000 miles or one year, whichever occurs first. If checking these filters, or at least offering to check these filters, for your customer for this reason alone is not enough, consider a few more.

Restricted filters will impact HVAC operation and component life. If the filter becomes restricted, the blower motor has to work harder to draw air through it and that can overheat the motor, resulting in early failure. It can also reduce airflow through the HVAC system, resulting in customer complaints of "A/C isn't blowing cold enough".

So help your customer breathe a little easier. Explain the importance of the cabin air filter to them and offer to inspect or service it for them when they come in for any routine maintenance service.

Additive packages

One topic I covered as part of the "Mighty Minute" series was coolant testing and service, and it's a topic I've covered a few times because it is so important to the health and longevity of the engine. I've also touched on this when it comes to engine oil and brake fluid.

The topic? Inspecting and testing the health of the fluid's additive package.

All these fluids have some kind of added chemical package designed to protect the base fluid from premature breakdown. When these additives are depleted, their protection is no longer there and the base fluid will quickly deteriorate and be unable to perform its role.

Coolants and engine oil have it harder than the brake fluid, I think, with many more factors that come into play that can cause the additives to become depleted early. Just because the bottle says it's a "lifetime" coolant, don't believe it! The coolant may last a lifetime but the additives won't, and if subjected to contamination from cylinder head gasket leakage or stray electrical current, the coolant may only last a few months before it requires replacement.

So how do you accurately test the coolant's additive package? By using a specialized test strip that measures the pH, or acidity, of the coolant. As the additives go away, coolant becomes more acidic and that's what accelerates the wear on the cooling system's various components - from water jacket plugs to water pump impellers.

pH test strips are the way to go to inspect the condition of the coolant and the brake fluid - both become acidic as the additive packages they contain become depleted.

As for brake fluid, we used to focus on water content. We all know that brake fluid is hygroscopic; that is, it can absorb water right out of the surrounding air, and that water contamination can lead to reduced boiling points. Not good for a fluid that plays so closely to components that generate a ton of heat!

And while moisture content is still a valid test, the focus shifted some time ago to the copper content in the fluid. Why?

The additive package, that's why. Or more precisely, the lack of one. As the additives depleted, corrosion inside the system would cause the copper coating on the interior of the metal brake lines to flake off and collect in the fluid. The amount of copper was an indication of the health of the additives, and in turn, the health of the brake fluid.

If we found high copper content, we recommended a brake fluid exchange to clean out the system and replace the old fluid with new.

And we flushed all the copper out at the same time. So NOW, if we test for copper content on a system that has been cleaned once already, there will be no indicators to help us judge the health of the brake fluid!

Thankfully, there are smarter guys than me on the problem. They discovered that, like the engine coolant, as the additives were depleted the fluid became more acidic. Now the BEST way to test brake fluid is to measure the pH of the fluid using specialized test strips you can get from your local parts supplier.

As for the engine oil

I don't know of any test strips for the engine oil to help assess the condition of its additive package but acidity is not the primary reason we need to change it regularly. No, it's to help flush out the contaminants that have collected there, the ones the filter was unable to collect.

And that's probably the biggest lesson I learned more recently. We all know how important it is to use the right oil for the application, right? (I hope everyone reading this does, anyway!)

But do you give the same consideration to the filter you're using on your customer's car? As I said in "The Trainer" video, it's been my experience that expensive doesn't always mean good but cheap is ALWAYS cheap!

The filter is responsible for catching as much of the debris from the oil as possible and a good filter will trap 99% of the debris down to 10 - 15 microns in size (that's really small!). The second factor to consider is how much the filter can hold. Changing your customer over to synthetic oil and doubling the service interval from 7,500 miles to 15,000 is not doing him any favors if the filter plugs up at the 5,000 mile mark and the internal bypass valve opens!

One more factor I like to consider is the quality of the construction. Does the filter have a good anti-drainback valve that will keep the filter full and prevent the dirty oil its holding from draining back into the crankcase on shutdown? Does it use an efficient filter element supported by metal ends or is cardboard used instead?

I actually cut a few name brand filters apart to see what they were made of and the results were, let's say, enlightening! Just because they have a big ad budget and an attractive spokesperson doesn't mean the filter will meet the task.

There's a lot more I could share but that's all the room I have this month. I'm hoping you took away something new from this just as I did working on these projects. If you did, be sure to check out the "Mighty Minute" and "The Trainer" series on our YouTube channel!

Sponsored Recommendations

Best Body Shop and the 360-Degree-Concept

Spanesi ‘360-Degree-Concept’ Enables Kansas Body Shop to Complete High-Quality Repairs

ADAS Applications: What They Are & What They Do

Learn how ADAS utilizes sensors such as radar, sonar, lidar and cameras to perceive the world around the vehicle, and either provide critical information to the driver or take...

Banking on Bigger Profits with a Heavy-Duty Truck Paint Booth

The addition of a heavy-duty paint booth for oversized trucks & vehicles can open the door to new or expanded service opportunities.

Boosting Your Shop's Bottom Line with an Extended Height Paint Booths

Discover how the investment in an extended-height paint booth is a game-changer for most collision shops with this Free Guide.