Knorr-Bremse Brake Components: Complete Guide

Knorr-Bremse Brake Components: Complete Guide Knorr-Bremse is the world's leading manufacturer of braking systems for commercial vehicles and rail. Their components are found in virtually every European truck and trailer manufactured in the last 30 years. This guide covers the complete range of Knorr-Bremse brake products, their applications, and how to source them efficiently for fleet maintenance. Table of Contents 1. Company Overview 2. Disc Brake Calipers 3. Drum Brake Components 4. EBS & ABS Systems 5. Brake Actuators 6. OEM Cross-Reference FAQ 1. Company Overview Founded in 1905, Knorr-Bremse has grown to become a €7+ billion global technology group specialising in braking systems. Their Munich headquarters oversees production at 100+ locations worldwide. Key product groups include: Disc and drum brakes for trucks, buses, and trailers EBS (Electronic Braking Systems) and ABS modules Air supply and treatment systems Driver assistance systems integration 2. Disc Brake Calipers SB7 Caliper The SB7 is Knorr-Bremse's workhorse caliper, fitted to hundreds of thousands of trailers across Europe. It uses a floating caliper design compatible with 430mm and 445mm brake discs. SB22 Caliper The SB22 is the successor to the SB7, offering improved pad wear sensing and a lighter aluminium housing. It is fitted as standard on most new European trailers from Schmitz Cargobull, Wielton, and Krone. SK7 Caliper (Truck/Axle Applications) The SK7 is Knorr-Bremse's primary caliper for truck axle applications, where higher clamping forces and greater thermal management are required. Model Application Disc Compatibility Max Clamping Force SB7 Trailers 430/445mm 185 kN SB22 Trailers (new spec) 430/445mm 195 kN SK7 Trucks (all axles) 377/400/430mm 240 kN 3. Drum Brake Components Actuating Cylinders Knorr-Bremse manufactures standard stroke and long stroke actuating cylinders for drum brake systems. The BKS and BA series are the most common in European commercial vehicle applications. Spring Brake Actuators Spring brake actuators (parking brake chambers) combine a service brake chamber with a spring-loaded parking brake. They are critical safety components—never attempt to disassemble a spring actuator without proper tools as the pre-loaded spring can cause serious injury. 4. EBS & ABS Systems EBS (Electronic Braking System) Knorr-Bremse's EBS systems integrate with the truck's CAN bus to provide advanced braking functionality including: Electronically controlled axle load distribution Integrated ABS and ASR functions RSS (Roll Stability Support) Emergency brake assist ABS Sensors Wheel speed sensors are one of the most commonly replaced Knorr-Bremse components. The D06/D07 passive sensors and the newer active sensors used in ECAM systems require specific cable lengths and connector types for each vehicle application. 5. Brake Actuators The BR and BA series actuator families are found on axles from SAF-Holland, BPW, and Jost. Correct sizing is critical—always verify the actuator size code (Type 24, 30, 36) matches the existing specification. 6. OEM Cross-Reference Knorr-Bremse Part MAN OEM Number Mercedes OEM Number Scania OEM Number SB22 Caliper (Right) MAN 81.50802-6128 MB A0074202583 SCA 1898988 K007644 ABS Sensor MAN 81.27420-6030 MB A0025427018 SCA 1524701 II35543F Spring Brake MAN 81.51100-6113 MB A0014201918 SCA 1369862 Find Knorr-Bremse components in our Knorr-Bremse catalog or browse all brake system components . 7. Knorr-Bremse Component Maintenance Guide Proper maintenance of Knorr-Bremse components ensures maximum service life and maintains the safety certification of the braking system. Key maintenance procedures: SB7/SB22 Caliper Service Calipers require servicing every 300,000 km or when brake pads are changed if guide pin corrosion is visible. Service kit includes guide pin boots, guide pins, and caliper slide seals. When the caliper is removed: clean all guide pin bores, inspect for pitting or scoring, apply high-temperature caliper grease (Knorr-Bremse recommends NLGI-2 bearing grease—never use copper paste on caliper slide pins). Spring Brake Actuator Inspection Spring brake actuators should be inspected for: Corrosion on the housing (particularly at weld seams on older units) Diaphragm integrity (push rod travel test—full stroke should be freely achievable) Clevis pin and yoke wear (replace if pin hole is visibly elongated) Boot condition (torn boots allow water ingress that causes diaphragm corrosion) Warning: Never attempt to disassemble a spring brake actuator in the field. The pre-loaded spring exerts force of 2,000–3,500 N and will cause serious injury or death if released uncontrolled. Replace the complete unit when it fails. ABS Sensor Maintenance ABS wheel speed sensors on commercial vehicles are passive (inductive) or active (Hall effect) type. Passive sensors (D06, D07) degrade through air gap variation caused by wheel bearing wear. Check: gap between sensor tip and tooth ring (0.2–1.5mm), sensor resistance (1.0–2.5 kΩ for D06/D07), connector condition. Active sensors (used in ECAM systems) require 12V supply and output a square-wave signal—test with an oscilloscope at wheel speed. 8. Ordering Knorr-Bremse Components: Reference Guide Correct part identification is essential for brake system components. Incorrect parts create safety risks and return/reorder costs. Use these identification methods: Identifying the Correct Caliper Locate the type stamp on the caliper body (usually near the bleed nipple or on the inboard face) Note the disc diameter—printed on the disc or measured directly Confirm left or right hand (LH = driver's side in UK/Eire, RH = driver's side in Europe) Note the axle manufacturer (SAF-Holland, BPW, Jost, ROR—different axle interfaces apply) Identifying the Correct Actuator Actuator size codes (Type 12, 16, 20, 24, 30, 36) indicate the effective diaphragm area in square inches. The type code is stamped on the actuator housing. The most common trailer application is Type 30/30 (combination service/spring brake). Never replace a Type 30 with a Type 24—under-sizing reduces braking force below legal requirements. ABS Sensor Cross-Reference Sensors are specified by cable length and connector type. The Knorr-Bremse part number suffix indicates cable length (e.g., 1200mm = /12). Use the truck's wiring diagram to confirm the correct cable length—too short prevents correct routing; too long creates chafing risk. Bay.Parts maintains an extensive Knorr-Bremse stock across all major component families. Contact our technical team for application-specific guidance and fleet pricing. Frequently Asked Questions Q: Are Knorr-Bremse aftermarket parts genuine? A: Knorr-Bremse sells both OEM (supplied to truck manufacturers) and branded aftermarket parts under the "Commercial Vehicle Systems" aftermarket division. Genuine Knorr-Bremse aftermarket parts carry the KB logo and product certification. They are equivalent in quality to OEM—in many cases they are produced in the same facilities. Beware of counterfeit brake parts; verify packaging security features and purchase only from authorised distributors. Q: How do I identify which Knorr-Bremse caliper is on my trailer? A: The caliper model code is stamped directly into the caliper body casting. On SB7 and SB22 calipers, look for the stamped code on the outboard face near the bleed screw. If the stamp is corroded and illegible, the disc diameter and axle manufacturer together determine the correct replacement caliper type. Q: Can I replace an SB7 with an SB22 caliper? A: They are physically interchangeable on most trailer axles (SAF-Holland, BPW) with compatible disc sizes, and the SB22 is an improvement over the SB7. However, verify the brake disc is compatible with SB22 before ordering—some older SAF-Holland axles use disc profiles specific to SB7. An incorrect fit creates dangerous brake imbalance. Q: How often should Knorr-Bremse ABS sensors be replaced? A: ABS sensors are wear items with typical service life of 400,000–600,000 km. Replace at first sign of intermittent ABS fault codes (which indicate signal dropouts), visible cable damage, or connector corrosion. On fleets with high trailer usage in salt-heavy winter environments, inspect sensors annually—salt corrosion on the sensor tip affects signal quality before physical damage is visible. Q: What brake pad brands are compatible with Knorr-Bremse calipers? A: The ECE R90 regulation ensures that any certified brake pad meeting the friction coefficient specification can be used in Knorr-Bremse calipers. Quality-compatible brands include TMD Friction (Textar, Jurid), Beral, Don Quichotte, and Ferodo. Always specify the pad to the caliper model and disc diameter—the pad backing plate profile must match exactly. 8. Knorr-Bremse Component Strategy for Fleet Operators Fleet operators running vehicles with Knorr-Bremse brake systems benefit from a systematic approach to component sourcing, inspection, and stock management. This section provides a practical framework: Standardised Brake Component Stock For fleets with 10 or more vehicles, maintaining a minimum brake component stock avoids costly downtime. Recommended on-hand stock per 10 vehicles equipped with Knorr-Bremse SB22 or SK7 systems: 2 sets of front axle brake pads (correct pad reference for caliper model) 1 set of rear axle brake pads 1 slack adjuster (Haldex type appropriate to trailer specification) 2 ABS wheel speed sensors (front axle reference) 1 EBS modulator repair kit (diaphragm and seals) Warranty Registration for OEM Knorr-Bremse Parts Genuine Knorr-Bremse parts purchased through authorised distributors come with a 24-month/unlimited-kilometre warranty when fitted by an approved commercial vehicle workshop. Retain all purchase invoices and workshop fitting records. Warranty claims are processed through the Knorr-Bremse Service Partner Network—ask your parts supplier for the nearest service partner when ordering warranty-eligible parts. End-of-Life Planning Euro 6 vehicles approaching 800,000 km benefit from a comprehensive brake system audit. At this mileage, it is common to find SB22 caliper bores showing scoring, EBS solenoid seals beginning to harden, and trailer brake valve seats showing wear. A proactive audit with replacement of worn components extends vehicle service life and avoids MoT/PTI failures. Contact Bay.Parts to arrange a fleet brake system audit and component supply quotation.