BUSRide Maintenance July 2015

JULY.2015

BUSRIDEMAINTENANCE.COM

THE EXCLUSIVE MAINTENANCE RESOURCE FOR THE TRANSIT AND MOTORCOACH INDUSTRY

AIR-DISC BRAKES: WHAT OPERATORS NEED TO KNOW p4

Monitor tire wear p6 | ABA launches BusMARC p7

FROM THE EDITOR IN CHIEF

Air-disc brakes – what operators need to know

VOL. 05 • NO.7 CEO Judi Victor jvfly@busridemaintenance.com

In this issue, BUSRide Maintenance takes a close look at air-disc brakes — and provides an in-depth Q&A about bus brake systems, purchasing advice, safety standards and replacement components/parts.

Brake OEMs (Bendix Commercial Vehicle Systems, DuraBrake, ProTec Friction Group and Meritor WABCO) talk about the advent of air-disc brakes, best buying practices, regulations, standards and specifications.

In addition, these industry leaders share their recommendations regarding the advantages of like-for-like purchases, as well as the advantages of air-disc brakes over brake drums. They talk openly about the pitfalls to avoid in the brake system aftermarket and they provide critical advice about vetting aftermarket suppliers.

We must never forget that motorcoaches and transit buses carry precious cargo. For this reason, there is perhaps no more essential bus component than an effective braking system. Expand your knowledge of aftermarket brake purchasing. This is not a place to cut corners.

Publisher Steve Kane skane@busridemaintenance.com Associate Publisher David Hubbard dhubbard@busridemaintenance.com Editor in Chief Richard Tackett rtackett@busridemaintenance.com Art Director Stephen Gamble sgamble@busridemaintenance.com Account Executive Jeanette Long jlong@busridemaintenance.com

Richard Tackett Editor in Chief BUSRide Maintenance Magazine

Accountant Fred Valdez fvaldez@busridemaintenance.com

JULY 2015

CONTENTS

BUS INDUSTRY SAFETY COUNCIL

On the cover: Air-disc brakes: What operators need to know

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What do bus and coach operators need to know about bus brake systems, brake technology, and replacement components and parts?

Where does the rubber from tire wear go?

6 A publication of:

By Christopher W. Ferrone

ABA announces BusMARC New council will raise the level of maintenance awareness in the intercity bus and motorcoach industry

7 POSTMASTER: Please send address changes to:

Departments From the Editor in Chief Products and Services 2

BUSRIDE MAINTENANCE | JULY.2015

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BUSRide Maintenance Magazine 4742 North 24th Street, STE 340 Phoenix, Arizona 85016 Phone: (602) 265-7600 Fax: (602) 277-7588 busridemaintenance.com

busridemaintenance.com

PRODUCTS & SERVICES

OPTI-PRO finds leaks The Tracerline® TP-8655 OPTI-PRO™ Plus is a cordless, rechargeable, true UV (violet light) LED leak detection flashlight. It emits less visible light, making leaks clearer and easier to spot. The OPTI-PRO Plus is engineered with a highoutput violet light LED that provides optimal fluorescent dye response and contrast. The OPTI-PRO Plus has an inspection range of 20 feet (6.1 m) or more. Its lightweight and compact body can easily get into tight, cramped areas that larger lamps can’t. The flashlight’s rugged, corrosion-resistant, anodized aluminum body stands up to years of heavy shop use. With power comparable to high-intensity 125watt lamps, it provides four hours of continuous inspection between charges.

Tracerline® Westbury, NY

Voith debuts eco-friendly drive systems With DIWA.6, Voith offers the ideal automatic transmission to meet the rising demand for clean and fuel-efficient vehicles for modern public transport, especially in view of the Euro 6 requirements. Specifically developed for city buses, the DIWA transmission offers the best preconditions for economical operation. Compared to its predecessor model, it saves almost another five percent of fuel. This is made possible by the topography-dependent gear-shifting program SensoTop, as well as the need-based reduction of the operating pressure and an intelligent start-up management that avoids starting against the active service brake.

Voith Heidenheim an der Brenz, Germany

Trans/Air improves reliability Trans/Air’s TM43 is a heavy-duty transit compressor for buses and coaches. It provides the high reliability and capacity only available from a transit compressor design for heavy-duty split system and rooftop applications. With a capacity of 80K (SAE) / 128K (IMACA) Btu/hr, features include a 10-cylinder swash plate for smooth operation, heavy-duty transit clutch in multiple configurations, flexible port and mounting design for easy installation, high and low pressure switches for protection, oil sump for reliability, and compact / light-weight design enabling mounting directly to the engine. Mount and drive kits are engineered for Ford F650/F750, Freightliner M2, and selected conventional school bus chassis.

Trans/Air Manufacturing Dallastown, PA

Warm up with Thermo Pro The Thermo Pro 90 engine-off coolant heater with up to 31,000 Btu/h of heating power offers new features specially designed for specialty commercial vehicles. It features improved fan motor durability and is bio-diesel compatible.

The Thermo Pro 90 offers offer quick warm-up times, low power consumption and high product quality. The Thermo Pro 50 is capable of up to 17,000 Btu/h of heating power and is available as a standard or heavy-duty kit. Both are available immediately, as compact kits (12V) or with enclosure box (12V and 24V).

Webasto Thermo & Comfort North America Fenton, MI busridemaintenance.com | BUSRIDE MAINTENANCE

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AIR-DISC BRAKES: WHAT OPERATORS NEED TO KNOW What do bus and coach operators need to know about bus brake systems, brake technology, and replacement components and parts?

I

The attempts to pressure balance, wear balance and heat balance the brakes come baked into the OEM design. Purchasing like-forlike when a replacement is necessary is important to maintaining those specifications. (Photograph courtesy of DuraBrake, Inc.)

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BUSRIDE MAINTENANCE | JULY.2015

n terms of foundation brakes, transit buses top the list of the most difficult applications to supply and manage (ahead of refuse trash collection).

The reason is the harsh operational environment in which the buses typically travel fully loaded on most mornings and evenings in cities with dense populations. Because transit buses make so many stops throughout the day, thermal energy is always a critical consideration. Energy builds in the brake system much faster than it releases into the air, and the brakes just get hotter and hotter.

Whereas brake drums were once the norm on buses, over the last 10 years motorcoaches have transitioned to all-wheel disc brakes. More recently, they’ve elevated as an option for transit buses.

The benefits of air-disc brakes over drum brakes include lighter-weight components, improved stopping distance and faster maintenance. busridemaintenance.com

Different friction materials used today often have their separate design compromises.

While one may offer superior heat for better braking performance, it may also be noisier or prone to depositing unsightly brake dust on the wheel rims. Another friction compound may have a soft feel and work quietly, but wear out much more quickly.

What are the dangers of Technicians must inspect regularly shopping solely on price? to ensure the minimum thickness Clearly the associated costs of of the brake rotors do not fall below vehicles equipped with disc brakes are The benefits of air-disc brakes over drum brakes specifications. For example, whereas the higher, as well as for replacement parts. For include lighter-weight components, improved original brake thickness of the surface the safety-minded operators, this should not stopping distance and faster maintenance. pads press against may start at 45mm, the come into play. Replacement brake parts are (Photograph courtesy of DuraBrake, Inc.) OEM rotors should always specify the safety-related components. Replacing a part minimum thickness before the rotor is no is not just about replacing it with a close facsimile. It is about taking steps to ensure the highest quality, longer safe. Technicians should always replace any rotor that especially considering the safety of the passengers. They deserve falls the minimum thickness. During an official safety inspection, an operator may receive a citation for driving a vehicle with a nothing less.

Bus and coach operators need to be cognizant of the minimum thickness lower than the written specification. proliferation of counterfeit brake products made to look incredulously similar to OEM products. In some cases, it is Describe some of the newest developments in often difficult to distinguish the fake from the original. It might brake technology.

Prior to antilock braking (ABS), required since 1998, even carry the OEM logo, brand name or part number. Unless operators really know the company, a price that seems too good brakes were entirely a mechanical function. ABS introduced electronics into the brake equation and became a great to be true probably is.

One suggested best practice for operators purchasing brakes platform for additional technologies such as ESC and collision parts is to vet aftermarket suppliers before they make any mitigation systems.

Some manufacturers have increased the content of expensive purchases. The more reputable suppliers of brakes have usually been in business for years, while others may turn out to be little alloys in their brake rotor such as molybdenum, nickel and more than a flash in the pan. There are aftermarket suppliers chromium in order to increase the strength and life of these that import from overseas without ever taking time to learn the parts. Alloy additives increase cost but they offer performance with longer life benefits. Unfortunately, cost savings often drive specifications and requirements for the safest brake parts.

The cheapest brake job may compromise safety. On the same companies to overlook the benefits of a quality product.

Carbon and ceramic composite brake-rotor developments are hand, the most expensive parts may not prove any safer than the standard part. Customers should research aftermarket suppliers, still on the drawing board, but the benefits would be a weight relying on test data, customer references and knowledgeable reduction by 40 to 50 percent. This is theoretically a longer life and they may never need replacing. Again, the cost would be safety-related information. significantly higher than conventional metal parts.

What overriding regulations, minimum standards and Can you offer specific guidelines and specifications dictate brake performance in heavyrecommendations to help bus and coach operators duty buses and motorcoaches?

Federal Motor Vehicle Safety Standards (FMVSS) 121 make safer, more cost-efficient choices in the area of establishes the minimum safety standards required for buses aftermarket brake repair and maintenance?

Strive for a like-for-like replacement. Wear and and motorcoaches with air brake systems over 10,000 GVWR to comply with the maximum stopping distance of a vehicle performance always suffers with replacement parts of different according to the National Highway Transportation Safety characteristics. Typically, one axel does less while another Administration (NHTSA). FMVSS 121 states buses must be works harder more to compensate.

Ideally, an operator does not want to use any replacement equipped with an antilock brake system (ABS) and be able to stop under a certain distance when moving at a maximum speed — part that interferes with the original system design. The attempts to pressure balance, wear balance and heat balance typically evaluated using a dynamometer in a laboratory setting.

Though the government sets the performance standards the brakes come baked into the OEM design. Purchasing for brake systems of new vehicles, it does not establish such like-for-like when a replacement is necessary is important to maintaining those specifications. specifications for replacement parts.

Given that a large percentage of consumer complaints to NHTSA involves brakes, the brake system is clearly one of the The companies DuraBrake, Meritor WABCO, ProTec Friction Group and Bendix Commercial Vehicle Systems contributed to the discussion on brakes for most critical elements of vehicle safety.

The brake rotor on air-disc brakes gets good thermal management because the hottest surface faces outward to the air and escapes in the wind. This alone reduces the major thermal energy that is so damaging. The hotter the brakes, the faster the pads and rotors wear.

commercial vehicles.

busridemaintenance.com | BUSRIDE MAINTENANCE

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Where does the rubber from tire wear go?

By Christopher W. Ferrone A great episode from Seinfeld has Jerry musing about where the rubber on his BMW tires goes when it rubs off.

This is truly an enigma. Like Jerry, it’s good to stop and remind ourselves of all that goes on with a set of tires. As tires wear, the material does in fact deposit onto the roadway and goes undetected because it happens so gradually.

The mechanical function of the tire casing is to contain the air pressure that supports the vehicle load, assure the function of the suspension by absorbing road irregularities, resist lateral drifting and centrifugal force, and transmit the torque necessary to move and stop the vehicle.

A number of factors affect the condition of a tire: the nature of its application for line haul, stop-and-go traffic (or a mix of both), the number of axles on the vehicle, overall maintenance of the tire during its life cycle and inflation pressure.

The major suspension and alignment adjustments control tire wear and condition. Technicians must monitor toe-in and toeout, caster angle and camber angle. However, not all vehicles have a front axle that allows the control of these adjustments.

Therefore, it is of vital importance to know the type of front axle on all vehicles and the allowable adjustments.

The most controlling factor in tire wear may be its inflation pressure. For every 10 psi a tire is under inflated, the life cycle of the tire is reduced by 10 percent. The amount of air in the tires affects the weight distribution between the wheels. An underinflated tire does not carry its share of the load. This condition affects torque, traction, steering, alignment, braking and cornering, and may cause pulling from side to side.

A tread separation usually means the tread has separated from the casing, disconnecting from the outermost steel belt. The outermost steel belt has become detached from the lower steel belt and the rest of the casing. Tread separation can be the entire tread or simply a section of the tread. This usually occurs later in the life of the tire casings unless a traumatic event has occurred.

A hole or some sort of damage that starts in the sidewall is normally the cause of a sidewall failure. Curbing the tire, striking a sharp object, age cracking and other structural issues all contribute to sidewall failures.

It is my belief that operators should never use retread or recapped tires on a motorcoach for any reason. When they experience failure they can damage the vehicle with the delaminated tread that is rotating with the tire casing, just as a circular saw would cut air hoses and suspension bellows during this type of failure.

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BUSRIDE MAINTENANCE | JULY.2015

A number of factors affect the condition of a tire.

Typically, the life cycle for a tire is four to six years, which corresponds to the average useful life of a tire casing. Despite the condition of the tread, tires should be taken out of service when they reach the four to six year mark. The DOT number embossed on the side of the casing notes the age of the tire. The last three numbers indicate the week and year of manufacture.

Technical staff must understand what affects tire condition and respond proactively. They must routinely monitor wheel alignment, inflation pressure and suspension adjustments in order to maintain proper tire performance. Additionally, if the vehicle has a steerable tag axle, technicians must also monitor those components to ensure the expected life cycle for the tag axle tires. busridemaintenance.com

ABA announces BusMARC New council will raise the level of maintenance awareness in the intercity bus and motorcoach industry The American Bus Association is again taking a significant leadership role in the motorcoach industry, announcing the formation of its new Bus Maintenance and Repair Council (recognized as BusMARC).

“It’s our goal to make sure the buses are on the road every day,” McDonal says. “The equipment must be maintained as well as possible to protect lives and reduce downtime.”

ABA Chairman John Meier says Mike McDonal has everyone’s full support, and sees BusMARC helping the association tremendously to take a significant leadership role in the industry that benefits members and the traveling public.

Photo courtesy of ABC Companies.

According to ABA, the BusMARC mission is to: • Raise the level of maintenance awareness in the intercity bus and motorcoach industry • Provide shop managers with the tools to build and improve their existing programs • Provide relevant and timely information to assist maintenance personnel with inspections and audits • Share information, including industry best practices • Bring together experts to collaborate on these maintenance issues “We have created BusMARC because ABA and its members believe there is a significant need in the motorcoach industry to assist companies of all sizes when it comes to collaborating on maintenance and repair issues,” says ABA President and CEO Peter A. Pantuso. “Industry and government officials understand that well-maintained motorcoaches, on regular maintenance cycles, are the safest vehicles on the road.”

ABA believes BusMARC will enhance safety for the hundreds of millions of people who travel by bus each year. It sees BusMARC as improving the relationship between motorcoach owner/operators, company maintenance directors, operations staff, coach OEMs, vendors and suppliers.

ABA has named Mike McDonal, manager of the Marylandbased motorcoach company Eyre Bus Tour and Travel, as chairman. McDonal is a past chairman of the Bus Industry Safety Council (BISC) and currently serves on a number of key industryrelated committees.

Membership in ABA is not a requirement for BusMARC membership. ABA invites all motorcoach owners, operators, maintenance professionals, shop supervisors and leaders from other segments of the industry to join. The first meeting of BusMARC will be held in conjunction with the ABA’s Marketplace, January 9-12, 2016, in Louisville, KY. “Recently the ABAs leadership including Board Chairman John Meier, Vice Chairman Don DiVivo and board members, began discussing the need and concept for BusMARC,” McDonal says.

“We agree that developing BusMARC is the next step because of the critical role maintenance is now playing in government compliance and the overall wellbeing of our travelers.”

He says by sharing the collective expertise of maintenance professionals, BusMARC can raise the standards and improve relationships with the OEMs.

busridemaintenance.com | BUSRIDE MAINTENANCE

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Tell us what you think the single most important motorcoach industry event has been in the past 50 years –

and you could win a

$100 AMAZON GIFT CARD! Simply email digitalissue@busride.com and we’ll follow up with you by email or by phone. You’ve got 50 words (one for each year of our anniversary) to tell us what rocked the motorcoach and transit industries most in the past five decades.