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Get ready for winter
with tune-up parts from MCI
www.mcicoach.com/PartsInfo
Welcome to the MCILEARN Series
Your Webinar Will Begin Shortly
Today’s Topic:
Well-Rounded:
Getting to Know Your Disc Brakes
If you do not have an audio connection, dial 877-739-5904 and enter the Audio PIN number given to you on your screen
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
Learning Objectives
During this training session, you will receive information on:
• How to identify components and their locations of the EX225 air disc
brake system
• How the EX225 components operate
• See the proper inspection procedures for the EX225 air disc brake
components
• Basic troubleshooting procedures for the EX225 air disc brake
components
• Recommended maintenance procedures for the EX225 air disc brake
components
• Where to find additional reference materials for the EX225 air disc brake
system
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
2
Safety Message
• Always use personal protection devices
•
Safety glasses, ear protection, etc
• Always observe all safety precautions listed in the Maintenance Manual
including but not limited to:
•
•
•
•
•
•
Ensure coach is on a level surface
Ensure parking brake is applied
Chock wheels
Always use jack stands
Shut off batteries
Utilize Lock Out/Tag Out procedures
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
3
EX225 Overview
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
MCI Disc Brake Evolution
ADB 1650
External Slack
External Auto Adjust
D-LISA
External Lever
Internal Auto Adjust
EX-225
Internal Lever
Internal Auto Adjust
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
5
EX225 Brake Overview
• Brake assembly and air chamber combined together as a sealed unit
•
•
•
No visible slack adjuster – no external adjustments
No stroke to measure – still requires operational inspections
Service Bulletins: Air System Operational Testing


3079 – D Series Coaches
3080 – E/J Series Coaches
• Steer and tag assemblies the same
• Provides approximately 30% more braking capacity than the Q+ drum
brakes
• Unitized Wheel Ends (UWE) and Preset Bearing/Hubs
•
•
Steer & 45’ Tag use Unitized Bearing/Hub Assembly
Drive & 40’ Tag axle uses Preset Bearing/Hub Assembly
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
6
EX225 Technical Features
• Sealed Eccentric
Operating Lever
• Integrated Twin Piston
Actuation & Automatic
Adjustment Module
• Durable Manual
Adjustment Device
• Improved / Enhanced
Sealing of Caliper
Assembly
• ‘Full Floating’ design
• Sealed Caliper Slide Pins
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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EX225 Components
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Steer & Tag Axle Caliper & Rotor Assemblies
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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Drive Axle Caliper & Rotor Assembly
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EX225 Brake Assembly Identification
• Identification tag with model
number, located on long guide
pin cover plug by manual
adjuster
•
May be in different locations
• Brake pad assembly/ friction
code. Identified by pad part
number on backing plate
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
11
EX225 Model and Specification Number
EX 225 H 301 AA 001
Housing Assembly
Platform
L = Standard Duty
H = Severe Duty
Pad Mix & Type
XX = No Pads
Min Wheel Size
225 = 22.5” Wheel
195 = 19.5” Wheel
Caliper Assy Family No.
2 = 285mm Wheel Mount
3 = 335mm Wheel Mount
Also defines bridges and other
options of base caliper assy
Chamber Options
000 = No Chamber
Housing, Bridge & Carrier
Lining & Chamber
Complete EX Brake Assembly
Part of ‘Service Caliper’
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
Sold Separately
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Visual Identification of MCI EX225H Calipers
• MCI uses only the (H2) or heavy duty axial version of the EX225 disc
brake !!
• Easy to visually determine the (H) type
•
Uses 6, 20mm dia. 30mm hex head bolts to mount carrier / caliper to the
torque plate

•
Uses 16mm dia. bolts for retaining bridge assembly. Bridge bolts will require a
14mm Allen type socket or an E20 female Torx socket

•
Light duty use 5
TORQUE YIELD BOLTS
Large pads installed, 9-13/16” long

See MCI document SB 2989 for more details
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
13
EX225 Brake Caliper Assembly
Caliper Mounted
Brake Chamber
Bridge
Carrier
Manual
Adjuster
Sealed Slide
Pins
Carrier
Mounting
Bolts
Bridge Mounting Bolts *
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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EX225 Brake Caliper – Sub Assemblies
3 Parts to ‘Service Assembly’
Housing
Bridge
Manual adjuster
Operating shaft and
bearings
Pistons, seals and
automatic adjuster
Carrier
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
15
Caliper Assembly– Exploded View
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16
Caliper Assembly – Cutaway View
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17
Cutaway Caliper
Operating
Lever
Self Adjuster
Mechanism
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18
Manual Adjuster Stem
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19
Manual Adjuster Stem Detail
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20
Automatic Adjuster Detail
• Close up of brake caliper ‘self-adjuster’ mechanism
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
21
Caliper Pad Wear Indicator
Wear indicator retracts into
the caliper housing as the
pads & rotor wear
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22
Caliper Pad Wear Indicator Cont’d
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EX225 Rotor Examples
Front / Tag Rotor (UWE)
Drive / Tag Rotor (Pre-Set)
WHAT’S DIFFERENT???
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
24
Pre-Set Hub Rotor Design
• The drive axle (and Pre-Set Tag)
rotor has a tapered vent design
and may appear to show
irregular or uneven wear
• The cooling vent is angled thru
the friction surface area of the
rotor
• This is a designed condition and
is normal
• The critical dimension for
inspection is ROTOR
THICKNESS
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
25
Detail of Design Change for UWE Rotors
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EX225 Inspection
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Brake Inspection Intervals
Use the most frequent from the intervals below:
• Fleet chassis lubrication schedule
• Chassis manufacturer lubrication schedule
• At least four times during the lining life
• At tire replacement
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
28
Initial Caliper Inspection - Caliper ‘Free-Running’
Clearance Inspection
• A check of proper adjustment
function
• With the wheel off attach the
dial indicator to the axle,
placing the indicator pin
parallel to a slide pin direction,
and sliding the caliper back
and forth by hand.
• If the reading is in excess of
2mm (0.080”) the “wheels-off”
adjuster check procedure
should be performed.
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
29
Automatic Adjuster Check Procedure
Operational Check
De-adjust ¼ turn ONLY
(park brake released)
Apply Service brake and observe
wrench rotation
Wrench only needs to
rotate slightly (15º - 30º) in
clock-wise direction to
pass inspection
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
30
Caliper Brake Pad Inspection
Even Wear
Complete
Contact
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31
Friction Material Inspection
Small chips of material missing
Large portions or whole sections of
friction material missing
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32
Friction Material Inspection Cont’d
Minor surface cracks in
friction material
Major cracks in friction material
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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Friction Material Inspection Cont’d
Minor gaps at edge of friction materials
Max Gap
.020”
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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Friction Material Inspection Cont’d
Minor surface grooving is
acceptable
Max Depth
.020”
Major surface grooving is
unacceptable
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
35
Brake Rotor Inspection - Gauging Rotor Thickness
• Check the rotor side-to-side
wear
• Use pad retainer as a gaugeif the retainer does not does
not fit between the pad
abutment and rotor surface,
the rotor is serviceable
• If the retainer fits between
the pad abutment and the
surface of the rotor, the rotor
should be replaced
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
36
Brake Rotor Inspection
Not less than 39 mm / 1.540” for
brake pad replacement
Minimum of 37 mm / 1.460” for
rotor replacement
Maximum allowable total run-out 0.020in or.5 mm
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
37
Acceptable Rotor Surface Conditions - ‘Bluing’
Acceptable condition but cause should be investigated
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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Rotor Surface Conditions - Heat Checks & Cracks
Heat checks (cracks) <75% of
pad contact surface
Cracks across pad contact
surface which contact edge
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
39
Unacceptable Rotor Surface Conditions - Grooving
• Grooves < 0.020” are considered acceptable.
• If grooves are >0.020” rotors can be re-machined or replaced.
Absolute minimum thickness 37mm / 1.460”
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
40
Vacuum Testing Caliper Housing
• Test chamber seals,
bellows & housing
seals for leakage
• Use 04-01-1171 Test
Plug and a “Mityvac”
tester
• Test entire caliper
housing assembly to 5
in/Hg Do Not Exceed
5 in/HG for testing!!
• Refer to MCI
SB #3023 for complete
detailed instructions
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
41
Inspection of Operating Chamber
Don’t forget to test chamber return spring!!
Check for proper protrusion
of chamber plunger @ rest
Verify operation of chamber
return spring
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
42
Inspection of Caliper Housing
Do Not Remove Seal Assembly From Caliper!
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
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Caliper Slide Pin Inspection
Inspect and Replace all damaged slide pin boots.
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
44
Inspection of Piston Boots
• Check the piston boots to make sure they are properly seated in the
piston seal retainer grooves.
• Replace any damaged boots
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
45
Carrier Brake Pad Abutment Inspection
Minor pad abutment wear is
normal and will not hurt the
performance of the brake.
However, wear in excess
that causes the pads to hang
up or not engage properly is
cause for a caliper change.
(These are examples of
minor to excessive wear
which have not met the out of
service criteria.)
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
46
Checking Slide Pin Bushings - Tangential Test
0.118in / 3.0 mm T.I.R.
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47
Checking Slide Pin Bushings - Radial Test
0.078in / 2.0 mm T.I.R.
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
48
EX225 Troubleshooting
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
Brake Drag
•
•
•
•
•
•
Incorrect initial adjustment
Broken or damaged disc pad anti-vibration springs
Incorrect pad-to-rotor clearance
Damaged, failed brake chamber assemblies
Vehicle air system malfunction
Caliper not releasing, internal mechanism damaged or corroded
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
50
Short Brake Pad Lining Life
•
•
•
•
•
Refer to brake drag issues first!
Caliper seized or sticking on guide pins
Damaged rotor surface
Companion brakes not functioning correctly
Vehicle overload
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
51
Smoking Brakes
• High brake temperature
• Contamination of brake pad lining material
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
52
Poor Braking Performance
•
•
•
•
Long stopping distances
Poor driver ‘feel’ of braking operation
High brake pressures
Vehicle ‘pulls’ to one side or another during braking
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
53
Brake Noise
•
•
•
•
•
•
•
•
Incorrect brake pad installation: BURNISH
Brake pads seized in carrier fixture
Worn brake pads
Brake component attachments incorrectly installed, loose, not installed
to specifications
Rotor cracks or excessive run-out
Pad springs damaged, incorrectly installed or missing
Incorrect pads installed
Bent or loose pad retainer on caliper
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
54
EX225 Maintenance Service Kits
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
Brake Pad Kits 04-01-1113
or Alternate 04-01-1164
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
56
Caliper Service Kits
04-01-1114 (RH) and 04-01-1115 (LH)
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
57
Slide Pin Kit 04-01-1116
(Guide Pins, Bolts & Seals Only)
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
58
Slide Pin Kit 04-04-1092
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59
Disc Pad Retaining Kit 04-01-1117
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60
Pad Wear Indicator Kit 04-01-1119
(4) Assemblies Per Package)
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
61
Caliper Mounting Kit
04-01-1120 Steer & Tag and 04-01-1121 Drive
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
62
Boot Kit 04-01-1118
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63
Additional Reference Material
for the EX225 Brake System
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
Special Tools Needed
•
•
•
•
•
•
•
•
•
Dial Indicator w/ magnetic or clamp base
14mm Allen hex socket
E20 Female Torx socket
T80 Male Torx bit
04-01-1178 Plug, inspection w/bolt or
04–01–1171 Test Plug
“Mityvac” hand-held vacuum tester
20-04-0012 12” torque adapter
20-04-0013 6” torque adapter
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
Used to torque carrier
mounting bolts to
torque plate
65
Additional Reference Material
• Available for free download at https://s3.amazonaws.com/helm-armlod/mm0467.pdf
http://www.arvinmeritor.com/customer/northamerica/lod/default.aspx
• ArvinMeritor Manual MM-0467 EX225 Disc Brakes
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
66
Summary
You should now be familiar with:
• How to identify components and their locations of the EX225 air disc
brake system
• How the EX225 components operate
• See the proper inspection procedures for the EX225 air disc brake
components
• Basic troubleshooting procedures for the EX225 air disc brake
components
• Recommended maintenance procedures for the EX225 air disc brake
components
• Where to find additional reference materials for the EX225 air disc brake
system
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
67
Questions and Answers
Click on the hand
to ask your question with your voice
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
68
Get ready for winter
with tune-up parts from MCI
www.mcicoach.com/PartsInfo
Thank you for being a valued
member of the MCI family!!
If you have any comments concerning this course, please email
them to [email protected]
©2013 Motor Coach Industries Int'l, Inc. and its subsidiaries. All Rights Reserved.
69