It's not what's up front that counts–it's what's underneath. The fleet manager's goal is to have his mechanics spend the lion's share of their efforts on preventative maintenance and the least amount of time on repairs.

By Jack Beardwood

How does a refuse fleet manager evade extensive refuse fleet repairs? His mechanics spend a vast majority of their time checking the fleet's underwear: brakes, wheels, suspensions, and tires. If not properly cared for, these items can be the bane of the fleet manager's existence, the proverbial Achilles' heel.

Simply put, the consequences of failed brakes on a 37,000-lb. trash truck with 20,000 lb. of payload can be devastating.

Proper brake shoes are a high-priority matter, according to Emile Hoffman, director of field technical support for Waste Management Inc., the nation's largest refuse firm, which is located in 48 states and has more than 33,000 vehicles on the road every day.

"We found in the industry that brake specifications didn't meet our applications, so we went to the brake manufacturers and asked them to design a brake compound to meet our stop-and-go kind of heat requirements. We are now requiring everybody to use these refuse-design brake shoes." The primary brands they use are Meritor and Brake Pro.

"We require them [managers at more than 1,500 locations] to inspect brakes at 150 hours of operation," states Hoffman. "On all brake replacements, we require them to replace full axle sets. In other words, if we have a brake that is wearing improperly on one of the tandems, they replace the whole tandem set [all four] of brakes, because we don't chase brake repairs. If you replace one brake set on the outside axle, say the left rear tandem, that brake takes an abnormal amount of the braking of the rest of the truck. So it starts wearing abnormally, or the other shoes wear abnormally. If you keep them in replacement sets, they wear evenly. That reduces our repairs. We're trying to maintain what we call brake balance to reduce the heat on one particular shoe."

By utilizing a laser heat-sensor gun, they can sniff out potential brake problems. If there's a couple of hundred degrees difference in the brake assemblies from one side of the axle to the other, there is a cause for concern, explains Hoffman. "Is it a dragging slack adjuster, a bad S-cam, or bad S-bushings? It [high heat] indicates poor brake balance, dragging brakes. They'll take the brake apart. They'll look at the S-cam, they'll look at the air supply, they'll look at the brake adjustment on the slack adjuster."

Hoffman reports that they have seen a dramatic savings in brake jobs by using an electronic drive-line retarder from a French company called Telma. Previously, their trucks required from five to12 brake jobs a year. With this retarder, they were able to extend brake jobs to as many as 21 months. "Because we average $1,300 a brake job, at the number of vehicles we have, if you just take out one brake job [per vehicle] a year, it's millions of dollars to us."

Keeping a meticulous eye on detail is essential in servicing the brakes, notes Steve Becker, a purchasing agent and former fleet manager for CR&R, a firm that serves more than 1 million people in 25 jurisdictions in California's Orange County. "When you do a brake job, you replace more than the brake shoes. You also replace the S-cam shaft and the bushings, if they're worn. You put new return springs on your brakes and the rollers on the cam shafts just so that they contact the drum. All of those things that get wear in them you have to replace–even the S-cam shafts when they get flat spots worn in them. Sometimes you replace the drums, you replace the shoes, and you make sure your slack adjuster is working properly."

The drivers play an integral role in preserving the efficiency of the brakes, states Ron Piombo, vice president/facilities manager for Marin Sanitary Service, which serves seven jurisdictions and hauls 60% of the refuse in California's Marin County.

"If the driver throttles between stops too much and then he has to brake heavily, once the heat gets to the shoes and the drums, you get a glazing effect. They harden up. Instead of having a good friction between the pad and the drum, you get this glaze in between. It's almost like rubbing metal against metal at that point, and you lose a lot of the capacity of the brake. Once they start hearing their brakes squealing, they've got them to where they're getting the glaze on them.

"We tell them when they smell the brake material, they certainly have it hot and they're doing something wrong at that point," continues Piombo. "We'll pull the drums off, and sometimes it's as simple as just running a file over the top of the brake shoe to remove the glazed area to get back down into the fiber of the brake. We can help them if they help us. It's all information and education."

Problems can also surface when the driver is working the maxi-brake before he comes to a complete stop, stresses Piombo. This causes undue wear to the rear-axle assembly components. "That can cause the brake to cock slightly inside the drum and drag while under normal driving, which will then create heat. It's almost as if you're driving with your foot on the brake. It's abusing the truck, certainly, and it's a simple thing to educate [the drivers on] and get away from that."

In most cases, Piombo observes, the drivers don't understand how the brakes work. To remedy this problem, he built a mockup of a brake drum with shoes on it, valves, a little dashboard, and an air tank that he pumps up. "I go through the whole process, how the brakes work, so they can mechanically see everything that's taking place. I can simulate an air leak. I can simulate applying the parking brake before they come to a stop, and that helps a lot. When they can visually see what's taking place–[like] the old saying that a picture is worth a thousand words–it really makes a difference. Anytime we see a problem and we feel that the driver doesn't quite understand, we take him to this mockup and go through it again. It has been helpful."

Marin Sanitary Service does a full-service and complete preventative maintenance inspection every 300 hours. Brake adjustments are done at least every 150 hours. Trucks that venture into the hills have their brakes adjusted every 80 hours. "They may not need it, but we will be under there with the inspection and actually measuring the brake adjustment."

Gerry Smalley, fleet manager for San Luis Garbage Company in San Luis Obispo, CA, says they can tell how well the driver is performing by checking out the brake linings. Prematurely setting the parking brake in an air system is a no-no. "They will be going about a mile or two an hour, and it's just like taking your car and jamming your emergency brake on as hard as you can. That wears out the brake lining quickly. We watch them. We explain to them not to do it. We reprimand them. We can tell by how often they wear out or are out of adjustment. Most of your citations written for trucks are for brakes out of adjustment. The way it works at our firm is, when a driver comes in and says, ‘My brakes are out of adjustment,' his truck doesn't move until we adjust them. It's a very big safety issue."

When it comes to keeping tires in good shape, the consensus among experts is that proper inflation is the number-one concern. "We have a strict program of checking the air pressure in the tire," relates Hoffman, "minimally twice a week through yard checks. And every time that truck crosses the door to the shop and comes in for maintenance, repairs, a brake adjustment, or anything else, the air pressure in every tire is checked.

"When a tire is 11 pounds below the recommended inflation, it's pulled because it's flat. Obviously, if you check a tire and get the air pressure up to 100 pounds of pressure and it comes back at 89 a day or two later, the tire has a problem. It is pulled for inspection and repaired."

Hoffman says the tires provide the telltale signs of good or evil in other areas on the rig. "The tires tell you the story. The tires tell you whether you have a front-suspension, camber, caster, or tow problem. They can also tell you whether you have a rear tandem axle alignment problem. The rubber of the tires gives the message to you that you have a problem. The same with a tire bead problem, where you have a high-heat application that your beads are failing. It isn't because your rubber is wrong. The tire is only the symptom. It's not the problem. The tire gives you the hint, ‘Hey, I'm sick, I've got a problem. Find my problem.'"

Minimum tire-tread standards for Waste Management Inc. is 4/32 for front axle steer and 5/32 for the rear-drive tires.

Smalley says his company, which has a fleet of about 100 trucks, has one employee whose sole job is to keep an eye on the tires. "He measures them for tread depth. We have front-end alignments done to keep the wear even in the front. If the rear suspension is worn out, that can cause the rear tires to wear unevenly. It's constant inspection."

Poor tire care can result in a multitude of consequences, points out Piombo. "If you don't care for them, they wear out a lot quicker. There is the possibility of rolling the truck over. The truck is not going to brake properly. If it's on the front end, it's not going to handle properly going down the road. You have the potential of a serious accident if your tires aren't properly maintained. The least of it would be just losing a lot of money. We run Michelin tires on the front, which are expensive. Some of the big tires are $500 or $600 a tire, and if you are only getting six or eight months of wear out of them because of improper pressure–rather than twice that or three times that–it can be costly in a fleet. It's definitely harder on the wheels, and it doesn't help the suspension."

He is not a fan of automatic tire-inflation systems. "The problem is you depend on them. It takes the man out of the system, where you're checking your air pressure every day on your trucks. You're also looking at your wheel lugs. If you've got automatic inflation and you pull a man away from that, you'll miss something. The visual inspection you just can't get away from. We find more things by just doing our routine visual inspection. We find more things that could be costly or dangerous."

Due to a substantial savings, Becker says CR&R utilizes retreads. "There are people who don't like the hassle because there are times when recaps can come off a tire. If you start with a good brand tire, like a Goodyear, a Michelin, or a Bridgestone, you have a tire casing that can usually be recapped several times. And that's where the value is in buying a [quality] tire. Sometimes it's not the initial cost but the fact that you're buying top-quality casing."

Choice of wheels on a rig can be important, depending on the job at hand. Piombo states that his trucks use mostly steel wheels. "We have a transfer station and don't cross too many scales, so I don't have to be too critical with weight. You can save a few hundred pounds on the whole truck [by running with aluminum], but that's not going to make or break me. I stay with the safety side of things. Steel is better. It's going to last a lot longer. They are less expensive."

To protect the wheels, he suggests that the air guns used to put on the lug nuts be inspected periodically. "We put them on a pressure gauge from time to time to make sure they have the proper pressure so that the lugs are getting on tight enough, but not too tight, so that you don't snap a stud. We educate the drivers before they wash their trucks to look at the wheel for little spider marks–what we call them–of dust coming from a wheel lug. It looks like little rust points. It usually indicates a loose wheel nut. We have them look for that because it's certainly a dangerous thing."

Becker says CR&R rolls with aluminum on the outside, because it looks good, and steel on the inside. "But you have to watch the lug nuts, make sure they're tight. And that's supposed to be inspected by the driver every day when he fills out his daily vehicle-condition report. You look for cracks in the wheels and for loose or missing lug nuts. Some of our trucks just have aluminum for the weight savings. I think a steel wheel is a little more durable than an aluminum wheel. When you tighten a lug nut up against an aluminum wheel, if you overtighten it, it will gouge into the aluminum and shorten the life of the wheel, because eventually you gouge it so far into the wheel it's no longer safe to use."

Generally, steel-wheel guarantees are 10 years, while aluminum carries a five-year warranty, explains Becker. "They just don't feel aluminum is as durable, with regard to developing a crack or having the lug-nut holes actually wear out from being taken off and on enough times."

One benefit of aluminum, according to Becker, is it dissipates the heat better. "Everything works better if it's kept cool. If your brakes get hot, the hotter they get, the less effective they are. As heat builds up in the drum and hub, it transfers out to the rims and tires. I think aluminum wheels tend to absorb some of that heat and dissipate it faster than steel wheels."

Caution must be taken with steel wheels because they have a tendency to be attacked by water inside of the tire, notes Hoffman. The water forms rust. As a result, the wheels need to be reconditioned more often.

The professionals also closely monitor suspensions. "You have to keep an eye on them because occasionally something can crack or come loose," maintains Becker. "When we service the trucks, we inspect the suspension. You look for cracks in springs or spring hangers and for worn bushings and pins. The shackles on the front springs become worn, and we have to replace the hangers as well as the shackles. Sometimes we have to replace the spring pins that are either broken or just badly worn. And occasionally, you'll find a broken leaf spring, where you'll have to replace either the entire spring pack or that particular leaf that has broken. If a spring is only two or three leaves thick, it will have a great effect on load-carrying capacity. You'll see the truck leaning, or the driver will notice it. Usually it's not a big thing. That's why they have so many leaves. If one breaks, it won't be a safety factor."

What makes suspensions wear out prematurely? "Poor maintenance is one thing," observes Becker. "If you don't lubricate your spring pins and shackles, they wear out pretty quickly sometimes, depending on the route. If they're on a lot of bumps or heavily loaded all the time, you get less life. Trash trucks, with their constant turning under heavy load, tend to wear out the bushings in the rear suspension. We have walking-beam suspension, and the bushings tend to wear. Pretty soon, the wheels don't stay in alignment when you make a turn. They walk way out to one side or another, and we know it's bushing time. So we buy the greasable bushings so we can keep the center bushings greased, and then they get a lot longer life than if you just go to the rubber center bushings."

A greasable center bushing on a walking-beam suspension will provide a much longer life for the components, he contends.

With the heavy loads it carries, a failed suspension could result in a serious accident, points out Piombo, who stresses attention be paid to greasing the pins, checking the rubbers, and inspecting for rub marks and cracks in the spring leaves. "Keep them steam-cleaned and washed, keep the dirt out, keep them lubed, and also be sure the e-bolts are properly torqued."

Becker says some of their vehicles have conventional suspensions, while others have Air-Ride Suspensions. "Air-Ride Suspension gives you a much safer ride and is better for delicate loads. Usually there are not too many components to wear out on an Air-Ride Suspension. Occasionally you'll get a leak in an airbag, but usually you'll get years out of them before that happens. With Air-Ride you can maintain the same ride height, no matter if you are loaded or unloaded."

"Air is a softer ride," notes Smalley. "It's good for trucks on long hauls. It's not sturdy enough for our type of operation in town, [which has] a lot of roughness. Our trucks go on dirt roads, even for garbage business."

When it comes to keeping maintenance costs down and keeping these behemoths on the roads, Becker puts the onus on the drivers. "I think the biggest failure is when the drivers fail to do their part in carefully checking out their truck before and after they hit the road. I think the drivers become lazy, and they tend to pencil-whip their reports. They don't look things over."

Piombo credits a computer program created by Ron Turley and Associates of Phoenix, AZ, with helping him efficiently manage his fleet. "It's changed my operation quite a bit. It's practically like having a crystal ball looking into your fleet. You're not trying to run all of this by paper, memory, and notes. The program tracks everything and keeps you on track with what is needed next. It can turn a fleet around. If you're doing 25% preventative maintenance and 75% breakdowns, a program like this can turn that around to where you're doing 75% preventative maintenance and only 25% breakdowns. And if you really want to put the time and effort into it, breakdowns will go to 4% or 5%, and that's where you should be. The cheapest way to maintain a fleet is preventative maintenance, rather than repairing breakdowns."

Writer Jack Beardwood has more than 20 years of professional experience working with newspapers and magazines.