Glossary, Federal bridge formula, Engine brake – Spicer Drive Axles Application Guidelines User Manual
Page 97: Exhaust brake

AXAG-0200 June 2009 97
Glossary
EBS
- The abbreviation for Electronic Braking System, or
brake-by-wire. A system in which the control signal is sent
electronically, rather than pneumatically, although the
actual service application is still made by air pressure.
ECE 13
- Uniform provisions concerning the approval of
vehicles with regard to braking in Europe.
ECU, ABS
- The abbreviation for Electric Control Unit, is
a microprocessor that evaluates how fast a wheel is
rotating. The electrical signals generated by the inductive
sensors pick up impulses from toothed rings that spin with
the wheel. It is part of an Antilock Brake System.
Edge Codes
- Developed by Friction Materials Standards
Institute, a double letter code (e.g., EE, FF, GG, FG)
printed on the edge of a brake block to designate its range
of friction in cold and hot test conditions.
EEC
- On the approximation of the laws of the member
states relating to the braking devices of certain categories
of motor vehicles and their trailers. Published in the
official journey of European Economic Communities.
Emergency Brake System
- Not a separate system,
emergency braking (in the event of air loss) involves
various portions of the parking and service brake systems.
See "
Spring Brake
".
End Play
- Looseness in bearing clearance in an axial
direction.
End Yoke
- Connects the drive shaft to other driveline
components.
Engine Brake -
A system that allows for slowing of a
vehicle that is independent of the conventional braking
systems. A driver would normally downshift to slow his
descent of a hill, using engine compression. The engine
brake increases the effectiveness of this retarding force.
Exhaust Brake
- Brake device using engine compression
pressure as retarding medium.
Fail-Safe, ABS
- If antilock brake system should fail
during vehicle operation, a dash light warns driver that
ABS is disengaged. Meanwhile, the
pneumatic
system returns to normal relay valve functions and
maintains standard air brake performance.
Fault Codes, ABS
- A series of codes displayed by the
self-diagnostic portion of the ABS unit, isolating the
section of the system that is now or has malfunctioned.
FC
- Fast Change style brake shoes, with standard
thickness lining.
FC XLII
- Fast Change style brake shoes, with extra thick
lining.
Federal Bridge Formula
- Formula that limits the weight
on groups of axles in order to reduce the risk of damage to
highway bridges. Allowable weight depends on the
number of axles a vehicle has and the distance between
those axles. However, the single or
axle weight
limits supersede the Bridge Formula limits for all axles not
more than 96" apart.
FMSI
- An industry standard number assigned to a brake
shoe lining. All shoe linings that have the same FMSI
number, should dimensionally be the same regardless of
brand.
FMVSS 121 (Federal Motor Vehicle Safety Standard
121)
- Performance Standard for air braked vehicles.
Foam Insert
- Foam piece also know as the compressible
insert.
Foot Valve
- A foot-operated valve controlling air
pressure delivered to the brake chambers.
Force Balance
- Optimum stopping capability requires
tire to road retarding forces in proportion to the loads on
all wheels.
Foundation Brake Balance
- Foundation brake balance
deals with the brake itself, (not including the air system)
brake lining, tire size, air chamber, slack length, etc. Can
be separated into two different aspects, torque balance and
thermal balance between different axles.
Foundation Brake System
- Term inclusive of
mechanical components involved in providing braking
force (i.e., brake chambers, slack adjusters, brake drums,
rotors and brake linings) on a vehicle.
Four Bag Suspension
- A single axle air ride suspension
with four air springs, usually located at each corner of the
suspension structure. The suspension moves up and down
as a parallelogram design.
Frame (Disc Brake)
- Structural element which supports
caliper and mounts brake assembly to torque plate.
Friction Couple
- Refers to the lining and drum
combination used to convert kinetic energy to heat energy.
Front Axle Limiting Valve
- See "
FT
- A fabricated brake shoe comprised of a stamped shoe
table and webs welded together.
Full-floating Axle
-
axle housing supports the vehicle ground load.
GAW (Gross Axle Weight)
- Total weight on a specific
axle position.