Training & Resources
Technical training videos, troubleshooting guides, and reference materials for commercial vehicle brake systems
Training Videos
Expert-led technical instruction for brake system service
Understand the critical difference between a rebuilt caliper and a professionally remanufactured unit — and why it matters for transit fleet safety and total cost of ownership.
- OEM vs. aftermarket component standards
- Inspection and quality control processes
- Warranty and service life expectations
- Correct application for Meritor EX225 systems
More videos coming soon
S-cam brake service, EX225 caliper service, air chamber replacement
Troubleshooting Guides
Common brake system issues with step-by-step AI-assisted diagnosis
Common symptoms:
- Excessive heat on one wheel
- Uneven brake wear
- Vehicle pulling to one side
Common symptoms:
- Brakes stay applied after air pressure builds
- Air chamber rod won't retract
- Hissing from chamber
Common symptoms:
- Brake stroke exceeds 2 inches
- Slack adjuster not self-adjusting
- Low brake torque
Common symptoms:
- Wear indicator light on
- Audible squeal at low speed
- Reduced stopping distance
Common symptoms:
- Brake shudder or pulsation
- Vibration through pedal
- Grooved drum surface
Common symptoms:
- Adjuster not advancing
- Excessive running clearance
- Uneven pad wear side-to-side
Quick Reference
Key specifications and service intervals at a glance
- Caliper series
- EX225L / EX225R
- Rotor diameter
- 17.0″ nominal
- Pad thickness (new)
- 30 mm
- Pad thickness (min)
- 2 mm
- Rotor thickness (min)
- 37 mm
- Max stroke (type 30)
- 2.5″
- Max stroke (type 24)
- 2.25″
- Lining thickness (min)
- ¼″ (6 mm)
- Drum diameter (max)
- OEM + 0.120″
- Slack adjuster arm
- 5.5″ standard
- Reservoir pressure
- 100–120 PSI
- Low pressure warning
- ≤ 60 PSI
- Brake application
- 90–100 PSI
- Full release time
- < 3 seconds
- Air dryer service
- Annual / 100k mi
Downloads
Technical documents, program guides, and service bulletins
Fraser Gauge's complete remanufacturing program guide for the Meritor EX225 disc brake caliper — covering inspection criteria, rebuild standards, quality control, and warranty terms.
Full technical specifications for the Fraser Gauge remanufactured Meritor EX225L caliper — transit bus & coach, right-hand side. Includes torque specs, materials, compliance, and installation notes.
Full technical specifications for ProRev Copper-Free Disc Pads — friction coefficients, Better Brake Law compliance, application compatibility table for EX225, SN7, and SB7 platforms, and installation notes.
Fraser Gauge 2026 Product Catalog
Complete catalog featuring all remanufactured calipers, rotors, and brake system components for Meritor EX225, Knorr/Bendix, WABCO PAN, and MAXX series.
Browse the 2026 Catalog In-Browser
Browse the full Fraser Gauge 2026 product catalog directly in your browser — no download required. Use the controls to zoom, navigate pages, and search.
Having trouble viewing? Download the PDF directly.
Disc Brake Glossary
Key terms for air disc brake systems — from the shop floor to the procurement desk
Air Disc Brake (ADB)
A brake system that uses compressed air to actuate a disc brake caliper, clamping brake pads against a rotor to slow the vehicle. Standard on modern transit buses and increasingly common on Class 8 trucks.
Caliper
The hydraulic or pneumatic actuator that clamps brake pads against the rotor. In air disc systems, the caliper contains the tappet, adjuster mechanism, guide pins, and seals. Fraser Gauge remanufactures calipers for Meritor EX225, Knorr SN7/SB7, WABCO PAN, and MAXX platforms.
Tappet
The piston-like component inside the caliper that transfers force from the adjuster to the brake pad. Tappets are replaced with new OE-quality units during Fraser Gauge remanufacturing.
Guide Pin
The sliding pins that allow the caliper to float laterally and apply even clamping force to both brake pads. Guide pin seizure — caused by corrosion or lack of lubrication — is the leading cause of premature caliper failure and uneven pad wear.
Adjuster Mechanism
The internal automatic slack adjuster built into air disc calipers that maintains correct running clearance between the pad and rotor as pads wear. A malfunctioning adjuster causes excessive stroke, uneven wear, or brake drag.
Running Clearance
The designed gap between the brake pad and rotor when the brake is released. Correct running clearance (typically 0.6–1.0 mm per side) prevents pad drag, heat buildup, and premature wear.
Rotor (Disc)
The rotating iron disc clamped by the caliper pads during braking. Rotors have a minimum thickness specification (discard limit); operating below this spec risks cracking and catastrophic failure. Meritor EX225 minimum rotor thickness is 37 mm.
Wear Sensor / Indicator
An electrical or mechanical device embedded in the brake pad that signals when pad material has worn to the minimum safe thickness. Fraser Gauge validates wear sensor function on every remanufactured caliper before shipment.
Core Exchange
A program in which a fleet returns a worn caliper (the "core") in exchange for a remanufactured unit. Fraser Gauge's Core Exchange Program stages units in advance so fleets receive a rebuilt caliper before returning the worn one, minimizing downtime.
Remanufacturing vs. Rebuilding
Remanufacturing involves complete disassembly, cleaning to bare metal, dimensional inspection, 100% new internal components, and factory-level testing. Rebuilding typically means replacing only failed components without full disassembly or testing. Fraser Gauge remanufactures — it does not rebuild.
FMVSS 121
Federal Motor Vehicle Safety Standard 121 — the U.S. federal regulation governing air brake systems on commercial vehicles. All Fraser Gauge remanufactured calipers and ProRev disc pads are compliant with FMVSS 121.
Better Brake Law
California (SB 346) and Washington State legislation phasing out copper in brake friction materials due to environmental contamination of waterways. Phase 1 limits copper to <5% by weight; Phase 2 limits to <0.5%. ProRev Disc Pads are Phase 2 compliant at 0 ppm copper.
Friction Coefficient (μ)
A dimensionless measure of the braking force a pad generates relative to the clamping force applied. SAE J661 classifies friction materials by two codes (e.g., "EE") representing cold and hot friction coefficients. ProRev pads are rated EE — consistent across operating temperature ranges.
Bed-In Procedure
A controlled break-in sequence performed after installing new brake pads or rotors. Involves a series of moderate stops from speed to transfer a thin, even layer of friction material onto the rotor surface. Skipping bed-in causes uneven material transfer, vibration, and reduced braking performance.
Pneumatic Pressure Test
A quality control procedure in which a remanufactured caliper is pressurized with compressed air to verify seal integrity. Fraser Gauge tests every caliper at 150 PSI — the same standard used in OEM manufacturing. A failed pressure test means the unit does not ship.
Need Parts for What You're Servicing?
Fraser Gauge stocks remanufactured calipers, service kits, and brake system components for Meritor EX225, Knorr/Bendix, and WABCO systems — ready to ship.