Download our catalogs and learn about programs, courses, tuition, fees, admissions and much more.
State-of-the-art, 248,000 sq.ft. Avondale campus will provide you with hands-on experience with everything from undercar maintenance to advanced diagnosis. Learn more here.
Find out what some of our graduates are doing today in pursuing their successful careers.
Learn more about how we assist our veterans from VA funding to exclusive scholarships.
UTI welcomes General Education Diploma students. Find out more in our resources.
Large commercial vehicles like tractor-trailers, busses, heavy equipment, and some personal vehicles such as large RV’s and tow vehicles have supplemental braking systems (diesel exhaust brakes and/or compression brakes). Supplemental braking systems are designed to safely slow the vehicle rather than completely relying on the brakes that are positioned at the wheels. Diesel exhaust brakes are a very common supplemental braking option.
Exhaust brakes are not a necessity on smaller diesel trucks and/or passenger vehicles because of their weight. Even when loaded, they are not nearly as taxing on traditional brakes. While not a requirement, many smaller vehicle owners will opt to install them via aftermarket providers.
Compression brakes (commonly referred to as ‘Jake Brakes’), which are identifiable by their signature loud “blat blat blat” sound, are an entirely different system than will be covered in a separate article.
Diesel exhaust brakes operate by physically restricting exhaust flow, creating additional backpressure, thereby slowing engine speed. The physical restriction comes in the form of a butterfly valve installed in-line in the exhaust system actuated by either a servo motor, air pressure or other means as needed to assist in slowing the vehicle.
If you’ve ever wondered, “what is a diesel exhaust brake?” you’re not alone. A diesel exhaust brake is an intentionally placed controllable physical restriction within the vehicle exhaust system that creates additional exhaust system backpressure, resulting in a reduction in vehicle speed.
A diesel exhaust brake is a system on large, diesel powered vehicle that allows for slowing and stopping without using the vehicle’s wheel mounted brake system. Diesel exhaust brakes, not to be confused with compression brakes, i.e.: Jake Brakes—can assist the wheel mounted braking system, therefore extending the useful life of components like brake pads, rotors and brake drums.
Additionally, the combined use of exhaust brakes and wheel mounted brakes can reduce stopping distance. Specifically, the stopping distance of heavy, fully loaded vehicles is reduced when both braking systems are used in tandem.
Diesel powered vehicles do not benefit from the same level of engine braking as gasoline powered vehicles enjoy. In a typical car or light truck, letting off the accelerator results in vehicle speed reduction beyond simple friction associated with moving an object through air and across a roadway. This slowing is caused by throttle valve closure, creating a vacuum for the engine to operate against.
Diesel engines do not use a throttle valve, as their operation is based on the regulation of fuel, rather than the regulation of air, as is the case with gasoline engines. This difference in engine design partially explains why diesel powered vehicles will “coast” for greater distances when the driver releases the accelerator.
Without a supplemental braking option, the combination of heavy loads and lack of engine braking easily overwhelms wheel brakes. Diesel exhaust brakes often are the preferred choice as they provide stopping benefits, but without the very loud noise associated with compression brakes. An exception would be heavy duty vehicles under significant load. In cases like this, compression brakes would be preferred as they provide the greatest braking force.
So, how does an exhaust brake work? Essentially, it works by trapping engine pressure in the exhaust system, which in turn forces the engine to rotate slower (backpressure).
Normally, pistons travel upward in their cylinder bore to force spent exhaust gasses out of the engine via the exhaust valve. When the exhaust brake is applied and the inline butterfly valve is partially closed, significant additional force is required to push the spent exhaust from the engine. This additional force slows the engine’s rotational speed. As the engine slows, the vehicle decelerates.
In some exhaust brake systems, the vehicle computer controls their operation. In others, the driver can manually actuate the exhaust brake. With either system, the mechanism which closes the butterfly valve may be powered by hydraulic pressure, air pressure or rely on an electronically operated servo motor.
Many diesel powered vehicles have supplemental braking systems, such as exhaust brakes. As a diesel technician, familiarity with their use and operation are important skills to have for your career. The braking systems require occasional maintenance and some users report decreased effectiveness over time. Properly inspecting, diagnosing, repairing and maintaining exhaust brake systems are important skills to have and can take you far in this industry.
While times might seem uncertain, the demand for diesel techs remains. Here's the inspiring story of UTI diesel grad Nestor Martinez.
After 35+ years of being in the Diesel Industry, Greg Osbourne is now an instructor at the UTI Bloomfield campus and is excited to share his experiences and show his knowledge in the Diesel Technician program.
Junior Alvarez graduated from UTI Avondale's Diesel Technology Program. He works as a Caterpillar field service tech by day. And he's an entrepreneur by night.
It only takes a few minutes to learn about technician training opportunities.
By submitting this form, I agree that Universal Technical Institute, Inc., Custom Training Group, Inc., and their representatives may email, call, and / or text me with marketing messages about educational programs and services, as well as for school - related communications, at any phone number I provide, including a wireless number, using prerecorded calls or automated technology. I understand that my consent is not required to apply, enroll or make any purchase.
1) UTI is an educational institution and cannot guarantee employment or salary.
2) For important information about the educational debt, earnings and completion rates of students who attended this program, and to review the applicable Gainful Employment disclosure, visit www.uti.edu/disclosures.
6) UTI graduates' achievements may vary. Individual circumstances and wages depend on personal credentials and economic factors. Work experience, industry certifications, the location of the employer and their compensation programs affect wages. UTI is
an educational institution and cannot guarantee employment or salary.
7) Some programs may require longer than one year to complete.
10) Financial aid and scholarships are available to those who qualify. Awards vary due to specific conditions, criteria and state.
12) Based on data compiled from the U.S. Bureau of Labor Statistics, Employment Projections (2016-2026), www.bls.gov, viewed October 24, 2017. The projected number of annual
job openings, by job classification is: Automotive Service Technicians and Mechanics, 75,900; Bus and Truck Mechanics and Diesel Engine Specialists, 28,300; Automotive Body and Related Repairers, 17,200. Job openings include openings due to growth
and net replacements.
14) Incentive programs and employee eligibility are at the discretion of the employer and available at select locations. Special conditions may apply. Talk to potential employers to learn more about the programs available in your area.
15) Manufacturer-paid advanced training programs are conducted by UTI’s Custom Training Group on behalf of manufacturers who determine acceptance criteria and conditions. These programs are not part of UTI’s accreditation.
Universal Technical Institute of Illinois, Inc. is approved by the Division of Private Business and Vocational Schools of the Illinois Board of Higher Education.