Severe duty maintenance: servicing the vehicles that work extra hard

Nov. 10, 2015
But even though they’re prone to age quickly, these vehicles in particular really need to be maintained and kept in good condition, not just for the safety and security of drivers and passengers, but also for everyone else sharing the road with them.  

Vehicles that spend extended time in stop-and-go traffic, idle for hours on end or constantly drive back and forth through the worst conditions and road surfaces will wear out pretty quickly if they’re not properly cared for. And since these vehicles often have many different drivers with very different driving styles, these hardworking vehicles often take a whole lot of driver abuse, which doesn’t help matters at all.

But even though they’re prone to age quickly, these vehicles in particular really need to be maintained and kept in good condition, not just for the safety and security of drivers and passengers, but also for everyone else sharing the road with them.

Additionally, some vehicles such as customized work trucks or specialized delivery vehicles are difficult and expensive to replace so it’s really important to keep these units running and in top shape for as long as possible.

From experience, vehicles that work extra hard tend to be much rougher on their braking and suspension systems, drastically reduce their fluid life, and also tend to drive around with various warning lights on so those are the systems that really need extra care and attention during routine  service.

With that in mind, here are a few idea and tips on inspecting, servicing and maintaining vehicles that work really hard so they stay safely and profitably on the road for a long time to come.

Preliminary checks
Even though hardworking vehicles do tend to develop more problems in specific systems, it’s still really important to inspect the entire vehicle carefully when it’s in for service.

Beginning with a thorough walk-around inspection is good practice – checking, among other things, that all the lights work, the ride height is OK, and that the horn works as needed (an inoperative horn may indicate blown fuses or electrical problems in the vehicle).

True, this is usually how any service inspection starts. But extra hardworking vehicles may have multiple drivers and there may be serious unreported problems that affect vehicle operation, and it’s important to notice them so they can be repaired during the service visit.

If there’s a log book in the vehicle, quickly flipping through it to find out if an operator has mentioned anything of note can save time. Also, checking the “appearance” items such as lights, wiper blades or other things that people notice creates a positive impression of your work with drivers, owners and operators and also reduces the chance of the vehicle being pulled over and ticketed during a traffic stop.

This trach bar ball joint separated when the truck went through a puddle. The yoke then smacked into the oil cooler and damaged it. The vehicle had to be towed and parts special ordered, which cost for more time and money than it would have to just replace the ball joint during routine service. This particular truck (F-350 4x4) travels about 200 miles each day at city speeds and almost never shuts off, but this brake leak at the master cylinder, noticed during inspection, definitely took it out of action until it was safe to drive again. 

Next, since sensors and emission components tend to reach the end of their lifespan much faster on hardworking vehicles, check for any warning lights that appear on the instrument cluster – warning lights that not only indicate problems but also create an annoying distraction during night driving.

Just quickly checking for warning lights by turning the ignition key ON (not to CRANK) and observing anything that comes on is a good idea that can help find problems lurking in the vehicle. Actually, it’s wise to also look for any lights that don’t come on too — the Malfunction Indicator Lamp or Check Engine light being the one most commonly missing, and this clearly indicates problems that should be investigated further. A flashing MIL light indicates serious problems – test driving that vehicle may do more harm than good.

One very experienced tech says he’s seen everything from electrical tape strategically placed on the instrument cluster to cover MIL lights, to warning light bulbs being removed, and even wires strategically snipped to get the lights to go off rather than pay to have the vehicle repaired correctly. Sadly, this isn’t uncommon.

Unfortunately since these types of repairs can get quite expensive, owners may not want to actually repair MIL-related problems but simply want to clear codes so that hopefully the warning light or lights turn off and they can continue on their way, especially if the vehicle still starts and drives acceptably. But while this might temporarily shut the light off – might! – it definitely won’t fix the vehicle’s actual fault, and it’s not a wise practice.

Road test
When actually starting the vehicle up, pay attention to how easily it turns over – listen for any sign of a battery that may need replacing during the service visit. If you have a digital battery tester, it may be a good idea to hook it up and evaluate the state of the battery that way too. It’s much easier to replace the battery during a regular service appointment than it is in a driveway on the coldest or busiest day of the year – and it’s faster too.

It’s important to look at the actual condition of the battery itself. Swelling, bulging, leaking or corroded components can and do lead to no-start conditions that can be prevented with a pre-emptive battery replacement. Be cautious about roughly wiggling the connections though – if there’s a problem, the connector may break right off in your hand.

Also be sure to check wiper and washer operation, the fan, heater and AC operation, and also check that the radio and speakers are all working well. Happy, comfortable drivers tend to be more careful with vehicles than drivers in malfunctioning ones.

While reading trouble codes, checking that the pedals move freely and the under dash area is free of debris and road salt that can damage wiring harnesses and sensors is also a good idea. Cracks at the bottoms of springs are common, and it's tough to inspect them properly when they're covered in mud. Shock absorbers will also wear out more quickly than nromal on hardworking vehicles, affecting braking distance and even affecting driver fatigue.

Suspension systems
During the road test it’s particularly important to check that any hardworking vehicle’s suspension system is in really good shape, especially if the vehicle travels endless miles through pothole-lined city streets or unpaved construction sites. Worn suspension parts not only affect braking and stopping distance, they can also increase driver fatigue – not good if the vehicle is used in severe situations or for extended periods of time.

The fact is, suspension systems work much harder on these units than they do on regular-duty ones and components will tend to break, bend or just wear out much more rapidly.

Since suspension components often fail gradually over time, the driver may well be used to the condition and not have mentioned that anything was wrong.

When the vehicle is back at the shop, look for suspension components and connections that are at extreme or strange angles – this may indicate damaged components that need to be replaced immediately. Also inspect the coil and leaf springs carefully. They tend to crack near the mounts and near the ends and the damage is often hidden by mud or dirt.

Also inspect any components that articulates as part of its normal movement, such as ball joints and tie rod ends, very carefully for excessive play or damage including damage or tears in the rubber boot seals. Since these wear out far more quickly on vehicles that work extra hard, it’s really important to replace them promptly when they’re at the end of their lifespan. It’s almost always cheaper, safer and easier to replace components before they fail, even though it can be a pain at the time.

One hardworking truck that regularly travels between construction sites recently came in for an oil change and the tech noticed play in the track bar ball joint. He recommended immediate replacement, but the customer  was in a rush and said he’d bring the vehicle back in a few days to have it changed then.

Sadly the truck went through a puddle shortly afterwards and the ball joint not only separated, the track bar yoke swung into and badly damaged the engine oil cooler. The result was a very expensive tow and the truck wasn’t drivable for a few days until the oil cooler was ordered and replaced. Fortunately no one was hurt; however, it could have been much worse.

And on that note, performing an alignment after suspension work is really important on these vehicles in order to maximize tire life.  Tires do tend to wear out more quickly and suffer more damage on vehicles that regularly carry heavy loads or are driven on rough or uneven roads so it’s important to help them last as long as possible.

It’s really important to not only have a good look at the suspension components, but also at the tires too – even if the preliminary walk around and road test didn’t indicate suspension problems and the customer hasn’t mentioned any problems. You may well find a problem that needs to be addressed.

Brake cables should move smoothly and freely, even on severe duty units that spend time off road. Suspension parts take a pounding on vehicles that work extra hard. Strange or extreme component angles usually mean broken or bent components, like this stabilizer link pictured.

Brakes
Since vehicles that work extra hard tend to be extra hard on their brakes, brake system components will need replacing much more frequently than brakes on regular-duty units. However, it’s important to be sure that the rapidly wearing brake parts are wearing out because of the amount of braking done in a short period of time rather than because of seized or binding components or hardware.

In other words, make sure that pads, pins and related components move freely and smoothly without binding or jamming because brake calipers, sliders, pins and seals are all adversely affected by the heat generated in stop-and-go traffic or by frequent hard braking – so making sure the seals are intact and the sliders move freely is really important.

If the vehicle is still using drums on the rear, make sure the wheel cylinders aren’t leaking, the hardware works and also that the brake cables move freely.

Additionally, if the vehicle uses a drum-in-hat type of parking brake, it’s definitely worth inspecting the mechanism closely and listening for rattles or other noises. Someone may have applied the parking brake at driving speed – especially if they don’t actually own the vehicle in question – and badly damaged the park brake components.

If the customer is interested in extending brake life, there are plenty of options available in the aftermarket.

While it’s never worth using low-quality parts for brake repairs, several manufacturers do produce excellent quality linings that perform well and last far longer than regular-duty or OEM products. There are a few possible trade offs to be mindful of though, such as increased noise and in some cases increased stopping distance compared to regular parts – and also the linings designed for longer pad life may wear away brake discs more quickly, which may mean that the discs cannot be machined and reused. But again, there are excellent products available if the customer is interested in switching to parts designed to last longer.

Fluids
Maybe the most important part of keeping severe duty vehicles on the road is changing the fluids regularly, as directed by the owners’ manual or supplement, using recommended fluids. It may be tempting to prolong change or service intervals, but that almost always ends up being much more expensive in the long run. Fluids need to be changed when they need to be changed to prevent damage and prolong component life.

Engine oil, for example, definitely needs to be changed when the owners’ manual recommends because as it breaks down it becomes acidic and can eat away at bottom-end components such as bearings, crankshafts and connecting rods.

It also needs to be changed regularly because it not only lubricates components, it’s also used to activate many engine valve timing controls (and other devices) and also traps combustion chamber deposits.

Extending the oil change interval too long can and does cause catastrophic and expensive engine damage. So even if that means multiple oil changes are required every month to keep up with the recommended intervals, it’s really important to do so. And if this is the case it might also be a good idea to stock oil pan drain plugs and gaskets and torque the drain plug every time to protect the threads in the oil pan.

Electric power steering is becoming much more common, but many hardworking vehicles – trucks in particular – still use hydraulic steering and the fluid does need to be serviced regularly. Discolored or contaminated fluid should definitely be replaced, as recommended by the manufacturer. Transmission, transfer case and differential fluids usually also need changing, but have a longer replacement or service interval and it’s crucial that they’re serviced on time to maximize the life of the component and prevent breakdowns. Taxis and delivery vehicles with failed transmissions aren’t very productive at all.

One interesting challenge, though, is that many manufacturers are moving towards sealed systems for components like transmissions or drive units. These components are sealed and never need fluid changes during their lifetime. (Although I’ve yet to meet a tech who doesn’t roll their eyes at the idea of “lifetime” fluid.)

But even these units will often have a service interval or recommendation listed in the owner’s manual or supplement. Look for additional service information for vehicles that operate in more extreme conditions and verify the manufacturer’s service requirements based on vehicle usage. You may be surprised at what you find.

Here's an example of something to look for when inspecting the vehicle. Notice the brake cable rubbing on the casing. Vehicles that regularly carry very heavy loads tend to have rear tires that wear quickly and springs that also wear out quickly or even break.

Lastly, one of the most important fluids and commonly overlooked ones in the vehicle is brake fluid, which definitely shouldn’t be neglected. Brake fluid is designed to absorb moisture in the brake system so that it doesn’t interfere with brake operation, and there will come a time when it requires replacement – which will be much sooner on severe duty vehicles. Check the service information to verify when the fluid should be replaced and be sure to check it regularly.

Conclusion
Working extra hard can accelerate wear and tear on suspension systems, brakes, fluid and even drivability systems, so it’s worth making sure these units get the maintenance and care they need.

Many shops take steps to develop customized maintenance plans for these vehicles, usually involving inspections of the critical components, fluid and filter changes, and keeping spares of components that frequently need replacing. They tend to be very good at quickly and thoroughly inspecting those vehicles while they’re in for service and noticing and repairing problems before they become serious.

There’s no way around the fact that vehicles need care and maintenance to keep them safely on the road – and vehicles that work extra hard need extra care. By carefully inspecting systems that tend to develop problems, replacing safety-critical and appearance items before they cause problems, and by working with the customers to use components that suit their needs, hardworking vehicles can spend many years and many miles on the road – and also return happily to your service bays.

Tires on hard-working units almost always take a pounding. Notice the chunk of tread missing from this one and the injury on the edge. Rubber bushings can separate, especially on vehicles that carry extra weight.

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