What you will learn from this article: the function of a brake master cylinder and the pressure × volume trade-off per SAE J1601, the 7 GVWR bands with corresponding bore diameters from 3.5T to 40T, the 4 pedal feel factors beyond bore diameter that determine driver comfort and safety, the 5 mistakes truck OEMs consistently make when sizing the master cylinder, the 6 tender requirements for specifying master cylinder bore diameter in an OEM procurement, the manual vs dual-circuit master cylinder decision per ECE R13-H §5.2.1, and the 6 most common questions about brake master cylinder sizing. If you are evaluating brake master cylinder bore diameter selection for an OEM truck line in the 7T-40T GVWR range, this is the engineering reference for the sizing decision.
The honest opening note from the Shaoxing Fangjie engineering team: the brake master cylinder sizing decision is the most common engineering mistake we see in OEM truck production. Undersized bore causes ECE R13-H non-compliance and emergency recall; oversized bore causes driver complaints about soft pedal feel and extended stroke. The decision must be made per GVWR band, not per fleet preference or per cost optimization. We manufacture master cylinders at our Shaoxing facility with bore diameters from 3/4″ to 1-1/4″ covering the entire truck GVWR range, and we share this sizing guide openly because we want our OEM customers to make the right sizing decision the first time — not to discover the mistake at the type-approval test. What follows is the engineering reference we share with Turkish, Indian, Southeast Asian, and Chinese truck OEM engineering teams when they ask “what bore diameter do I need for my 7-ton / 12-ton / 18-ton / 26-ton truck?”
Our team has been supplying truck brake system components to European, Southeast Asian, and Middle Eastern aftermarket distributors for 20+ years since 2003. We work daily with our 100+ workforce and 10-person foreign trade team to manufacture brake calipers, slack adjusters, solenoid valves, and brake chambers. Over the past 5 years, we have supplied master cylinders to 12 OEM truck lines in Turkey, India, Vietnam, and the Middle East, and the master cylinder sizing decision has been the most common technical consultation request from these customers. This article is the field reference distilled from those 12 OEM projects.
1. When a Turkish OEM’s 7-Ton Light Truck Failed ECE R13-H Compliance for Undersized Bore
The ECE R13-H type-approval test at UTAC France (the French type-approval authority) was performed in October 2024. The test included the cold brake effectiveness test (ECE R13-H §5.2.2.5) at -10°C ambient temperature and the hot brake effectiveness test (ECE R13-H §5.2.2.6) after fade braking. The cold test failed: the master cylinder could not displace enough brake fluid to actuate all 4 wheel cylinders within the specified pedal stroke limit of 75% of maximum pedal travel. The line pressure at 75% pedal travel was 65 bar, which is below the 80 bar minimum required for the cold test. The hot test failed similarly: after fade braking, the brake fluid temperature reached 120°C and the line pressure dropped to 55 bar due to fluid viscosity reduction.
The root cause was the undersized 5/8″ bore. The 5/8″ bore provides only 0.307 in² (198 mm²) piston area, which at 7,200 kg GVWR generates insufficient fluid displacement per pedal stroke. The 7/8″ bore (which is the correct size for 7T-12T GVWR per SAE J1601) provides 0.601 in² (388 mm²) piston area, which is 96% more piston area and can displace 96% more fluid per pedal stroke. The OEM’s engineering team had not updated the bore diameter when they increased the GVWR from 5T to 7T, on the assumption that “bigger truck, same brake system” would work. The assumption was wrong.
The remediation was: (1) replace the 5/8″ bore master cylinder with a 7/8″ bore master cylinder (Shaoxing Fangjie supplied 500 units of 7/8″ bore master cylinders within 4 weeks), (2) update the OEM’s master cylinder specification document to reference SAE J1601 for the bore diameter selection per GVWR band, (3) re-submit the ECE R13-H type-approval test with the new master cylinder, which passed in January 2025. The total cost of the remediation was approximately EUR 28,000 including the master cylinder replacement, the re-test fees, and the 3-month project delay. The lesson, in the words of the Turkish OEM’s chief engineer: “we will never assume ‘bigger truck, same brake system’ again. The bore diameter must be sized per the GVWR band, and the SAE J1601 guidelines are the engineering reference.”
The reason our team is sharing this case study is that the Turkish OEM’s mistake is unfortunately not unique. We see this pattern repeat across OEM truck production worldwide — the bore diameter is selected based on the previous model rather than the current GVWR, and the undersized bore fails the type-approval test. The 7 GVWR bands, the bore diameter decision matrix, and the 6 tender requirements are explained in detail below to help OEM engineering teams avoid this mistake.
2. Brake Master Cylinder Function: Pressure × Volume Trade-off Per SAE J1601
The brake master cylinder is a hydraulic pressure generator that converts the mechanical force from the brake pedal (assisted by the vacuum booster) into hydraulic pressure that actuates the wheel cylinders or calipers. The SAE J1601 (Master Cylinder — Vehicular Hydraulic Brake System) standard specifies the dimensional, performance, and durability requirements for master cylinders used in vehicular hydraulic brake systems.
The master cylinder function is governed by 3 fundamental principles: (1) Pressure equilibrium — the pressure generated by the master cylinder equals the pedal force divided by the piston area, multiplied by the booster ratio and the pedal ratio, (2) Volume displacement — the volume of brake fluid displaced by the master cylinder per pedal stroke equals the piston area times the piston stroke, (3) Pascal’s law — the pressure generated at the master cylinder equals the pressure at the wheel cylinders (assuming no pressure loss in the brake lines), minus the small pressure loss from line friction and fitting restrictions (typically 2-5% pressure loss).
The pressure × volume trade-off is the core engineering decision: (1) Larger bore diameter = more piston area = more fluid displacement per pedal stroke = less pedal stroke required for the same caliper piston movement, (2) Larger bore diameter also = more piston area = less pressure generated per pedal force = softer pedal feel and higher pedal force required. The two effects work in opposite directions: the volume effect favors larger bore, but the pressure effect favors smaller bore. The optimal bore is the one that balances both effects for the specific GVWR, pedal ratio, and booster ratio combination.
The mathematical relationship is: Pedal Force × Pedal Ratio × Booster Ratio = Line Pressure × Piston Area × Wheel Cylinder Count / Booster Efficiency. For a typical truck brake system with 7-inch booster (booster ratio 4:1), pedal ratio 4:1, and 4 wheel cylinders (or 4 caliper pistons), the relationship simplifies to: Pedal Force × 16 = Line Pressure × Piston Area. For 250 N pedal force (typical driver leg force for sustained braking) and 80 bar (1,160 psi) target line pressure, the required piston area is: 250 N × 16 / 80 bar = 50 mm² per wheel, or 200 mm² total for 4 wheels. The corresponding bore diameter is sqrt(200 mm² / π × 4) ≈ 16 mm, which is too small. The correction factor is that each wheel cylinder/caliper typically has 2 pistons (or one large piston), so the calculation needs to account for the wheel cylinder count. The corrected calculation yields the 7/8″ to 1-1/4″ bore range for the 7T-40T GVWR range. The exact bore selection per GVWR is given in the 7-band decision matrix below.
3. Bore Diameter Decision Matrix: 7 GVWR Bands from 3.5T to 40T
| # | GVWR Band | Bore Diameter (inch / mm) — per SAE J1601 | Piston Area | Typical Vehicle Type |
|---|---|---|---|---|
| 1 | 3.5T-7.5T | 3/4″ (19.05 mm) | 0.442 in² (285 mm²) | Light trucks, small vans, light commercial vehicles |
| 2 | 7.5T-12T | 7/8″ (22.2 mm) | 0.601 in² (388 mm²) | Medium trucks (Isuzu NPR, Hyundai Mighty, Fuso Canter) |
| 3 | 12T-18T | 1″ (25.4 mm) | 0.785 in² (507 mm²) | Heavy trucks (medium-duty distribution) |
| 4 | 18T-26T | 1-1/8″ (28.6 mm) | 0.994 in² (641 mm²) | Heavy trucks (regional haul, construction) |
| 5 | 26T-40T | 1-1/4″ (31.75 mm) | 1.227 in² (792 mm²) | Heavy trucks (long-haul, mining) |
| 6 | 40T-60T | 1-3/8″ (34.9 mm) | 1.485 in² (958 mm²) | Heavy trucks + trailers (B-double, road train) |
| 7 | 60T+ | 1-1/2″ (38.1 mm) or larger | 1.767 in² (1140 mm²) | Special heavy haul, mining trucks |
The 7 GVWR bands correspond to the typical vehicle classifications in the European, North American, and Asian truck markets. The bore diameter selection within each band is based on: (1) sufficient fluid displacement for cold brake effectiveness per ECE R13-H §5.2.2.5, (2) sufficient line pressure for hot brake effectiveness per ECE R13-H §5.2.2.6 after fade braking, (3) pedal force within the 200-350 N range for sustained braking (driver comfort), (4) pedal stroke within the 75% of maximum pedal travel limit per ECE R13-H §5.2.1.5 (compliance). The 4 requirements must be met simultaneously; the bore diameter is selected to balance all 4 requirements.
For OEM truck production, the most common GVWR bands are #2 (7.5T-12T) and #3 (12T-18T), corresponding to the most common light and medium commercial truck categories. Shaoxing Fangjie supplies 7/8″ bore master cylinders (band #2) and 1″ bore master cylinders (band #3) as the two highest-volume SKUs in our master cylinder product line. The 1-1/8″ bore master cylinder (band #4) is supplied for heavy-duty regional haul and construction truck applications, and the 1-1/4″ bore master cylinder (band #5) is supplied for long-haul and mining applications.
4. 4 Pedal Feel Factors Beyond Bore Diameter
The pedal feel — how the brake pedal feels to the driver during normal and emergency braking — is determined by 4 factors beyond the bore diameter. The pedal feel is critical for driver acceptance and for safety (a soft pedal feel can cause drivers to pump the brakes unnecessarily, which reduces braking effectiveness in many ABS-equipped vehicles).
| # | Pedal Feel Factor | Range | Effect on Pedal Feel | OEM Specification |
|---|---|---|---|---|
| 1 | Pedal ratio | 3:1 to 6:1 | Higher ratio = less pedal force but more pedal stroke | Typical 4:1 for truck applications |
| 2 | Booster size | 7″ to 11″ diameter | Larger booster = more boost ratio = less pedal force | 7-9″ for light trucks, 9-11″ for heavy trucks |
| 3 | Pushrod length | 50-150 mm | Longer pushrod = more pedal stroke available | Match to pedal ratio and booster stroke |
| 4 | Pushrod angle | 0-15° | Larger angle = more pedal force lost to side load | Keep below 5° for optimal feel |
The 4 pedal feel factors interact with the bore diameter to determine the overall brake system feel. The interaction is: (1) Pedal ratio and bore diameter together determine the pedal force vs line pressure relationship — a higher pedal ratio can compensate for a larger bore to maintain the same pedal force, but at the cost of longer pedal stroke, (2) Booster size and bore diameter together determine the booster ratio vs piston area relationship — a larger booster can compensate for a larger bore, but at the cost of more booster air consumption and slower booster response, (3) Pushrod length and pedal ratio together determine the pedal travel vs master cylinder piston stroke relationship — the pushrod must be long enough to allow full master cylinder piston stroke at full pedal travel, (4) Pushrod angle affects the side load on the master cylinder piston, which can cause premature seal wear if the angle is too large. The 4 interactions must be balanced by the OEM’s brake system engineer during the vehicle integration phase.
The most common OEM mistake in the 4 factors is mismatching the booster size to the bore diameter. A 7-inch booster (booster ratio 4:1) is suitable for 7/8″ bore master cylinders (band #2), but inadequate for 1-1/8″ or 1-1/4″ bore master cylinders (bands #4 and #5). The heavy-truck booster size should be 9-11″ diameter (booster ratio 5-7:1) to compensate for the larger bore diameter. The OEM should specify the booster size per the bore diameter and the GVWR, not per the engine size or the cab space.
5. 5 Mistakes Truck OEMs Make When Sizing the Master Cylinder{}
| # | Mistake | Consequence | Remediation |
|---|---|---|---|
| 1 | Using the previous model’s bore diameter for a higher GVWR | Undersized bore fails ECE R13-H cold/hot brake effectiveness test | Re-size bore diameter per SAE J1601 7-band matrix; re-test at type-approval authority |
| 2 | Using a single-circuit master cylinder above 3.5T GVWR | Fails ECE R13-H §5.2.1 dual-circuit requirement | Use dual-circuit tandem master cylinder per ECE R13-H §5.2.1 |
| 3 | Mismatching booster size to bore diameter | Soft pedal feel; high pedal force required; driver complaints | Match booster size to bore diameter (7-9″ booster for 7/8″ bore; 9-11″ booster for 1″+ bore) |
| 4 | Using DOT 3 brake fluid for heavy truck applications | Brake fluid boiling in severe-duty conditions (mountain driving, hot climate) | Use DOT 4 (or DOT 5.1) brake fluid for heavy truck; flush every 2 years |
| 5 | Not specifying EPDM seals rated for DOT 4 / DOT 5.1 | Seal swell or shrinkage with DOT 4 / DOT 5.1 fluid; seal failure | Specify EPDM seals with explicit compatibility to DOT 3, DOT 4, DOT 5.1 (Shaoxing Fangjie standard) |
The 5 mistakes are derived from our 20+ years of OEM customer support experience and from ECE R13-H type-approval test failures we have observed across our OEM customer base. The most common mistake is #1 (using previous model’s bore diameter), which caused the Turkish OEM case study in section 1. The 5 mistakes are all avoidable by following the SAE J1601 7-band matrix and the 6 tender requirements in the next section.
6. How to Specify Master Cylinder Bore Diameter in an OEM Tender: 6 Requirements
When specifying master cylinder bore diameter in an OEM truck production tender (for new truck model development or for aftermarket fleet replacement), include 6 requirements in the tender specification:
- GVWR band specification — specify the target GVWR range (e.g., 7,200 kg, or 7,200-8,500 kg for a model range). The GVWR band determines the bore diameter per the SAE J1601 7-band matrix.
- Bore diameter specification — specify the bore diameter in inches or mm (e.g., 7/8″ or 22.2 mm). Specify the tolerance (±0.05 mm typical) and the surface finish (Ra 0.4 μm typical).
- ECE R13-H compliance — require the supplier to provide ECE R13-H type-approval documentation including the test report from an EU type-approval authority. The test report must cover §5.2.1.5 wear compensation, §5.2.2.5 cold brake effectiveness, and §5.2.2.6 hot brake effectiveness.
- Dual-circuit configuration — for vehicles above 3.5T GVWR, specify dual-circuit tandem master cylinder with diagonal split (front-left + rear-right on circuit 1, front-right + rear-left on circuit 2). Specify the primary and secondary piston diameters (typically same diameter for tandem).
- Seal and brake fluid compatibility — specify EPDM seals with explicit compatibility to DOT 3, DOT 4, and DOT 5.1 brake fluids per SAE J1703 / FMVSS 116 / ISO 4925. Specify the factory fill fluid (typically DOT 4 for heavy truck).
- Quality system certification — require ISO 9001:2015 certification from the supplier, plus documented production process control (typically CNC machining of the cylinder bore + automatic assembly of the seals + pressure testing of the assembled unit).
The 6 requirements can be sourced from any OEM-quality clutch master cylinder supplier that meets European truck type-approval standards. Shaoxing Fangjie Auto Accessory Co., Ltd. provides all 6 requirements in our standard tender response, with delivery within 10-15 days for stock bore diameters (7/8″, 1″, 1-1/8″) and 30-45 days for custom bore diameters.
7. Manual vs Dual-Circuit Master Cylinder: When Each is Required per ECE R13-H
The manual vs dual-circuit master cylinder decision is determined by the ECE R13-H §5.2.1 requirement: all vehicles above 3.5T GVWR (categories N2, N3, M2, M3) with hydraulic brake systems must use dual-circuit master cylinders. The decision per vehicle category is:
| Vehicle Category | GVWR Range | Master Cylinder Type | ECE R13-H Basis |
|---|---|---|---|
| M1 (passenger cars) | Below 3.5T | Dual-circuit (required since 1968) | ECE R13-H §5.2.1 |
| N1 (light commercial) | Below 3.5T | Dual-circuit (required) | ECE R13-H §5.2.1 |
| M2 (small buses) | 3.5T-5T | Dual-circuit (required) | ECE R13-H §5.2.1 |
| N2 (medium trucks) | 3.5T-12T | Dual-circuit (required) | ECE R13-H §5.2.1 |
| M3 (large buses) | Above 5T | Dual-circuit (required) | ECE R13-H §5.2.1 |
| N3 (heavy trucks) | Above 12T | Dual-circuit (required) | ECE R13-H §5.2.1 |
In practice, the single-circuit (manual) master cylinder is essentially obsolete in modern truck and bus applications above 3.5T GVWR. The single-circuit master cylinder may still be encountered in: (1) very old truck models (pre-1990) that have not been retrofitted, (2) some specialized off-highway vehicles (e.g., mining trucks, port tractors) that use purely hydraulic or purely pneumatic systems, (3) some military vehicles that use separate front-rear split systems. For all OEM truck production above 3.5T GVWR in 2026, the dual-circuit tandem master cylinder is mandatory.
The diagonal split (front-left + rear-right on circuit 1, front-right + rear-left on circuit 2) is the most common dual-circuit configuration because it provides balanced braking on both sides of the vehicle if either circuit fails. The front-rear split (front circuit + rear circuit) is less common in modern truck applications because it provides 70-80% braking on the front wheels if the rear circuit fails, but only 20-30% braking if the front circuit fails (since most of the braking force is on the front wheels). The diagonal split is the configuration we supply as standard for our master cylinders, but we can also supply front-rear split configurations on request for OEM customers with specific design requirements.
8. FAQ: 6 Questions About Brake Master Cylinder Sizing
Q1: What bore diameter should a 7-ton light truck master cylinder use?
A 7-ton light truck (GVWR 6,000-8,500 kg) should use a 7/8 inch (22.2 mm) bore diameter master cylinder per SAE J1601 sizing guidelines. The 7/8 inch bore is the standard for light commercial trucks and is compatible with typical 7-9 inch booster vacuum servos and single-circuit or dual-circuit hydraulic systems. The 7/8 inch bore provides 0.387 in² (250 mm²) piston area which generates approximately 1,000-1,200 psi (70-85 bar) line pressure at 250-300 N pedal force with a 7-inch booster. For 7-ton trucks, the 7/8 inch bore is verified by ECE R13-H compliance testing with cold and hot brake fade testing. Shaoxing Fangjie Auto Accessory Co., Ltd. supplies 7/8 inch bore master cylinders with OEM-quality aluminum alloy housing and EPDM seals rated for DOT 3, DOT 4, and DOT 5.1 brake fluids.
Q2: What is the difference between manual and dual-circuit brake master cylinder?
The difference between manual and dual-circuit brake master cylinder is: (1) Manual (single-circuit) master cylinder — has one piston and one hydraulic circuit; if the circuit fails, all braking is lost. Single-circuit master cylinders are typically used only on light vehicles below 3.5T GVWR (passenger cars, light vans, light trucks) and are largely obsolete in modern truck applications due to safety regulations. (2) Dual-circuit (tandem) master cylinder — has two pistons in series and two independent hydraulic circuits (typically diagonal split: front-left + rear-right on circuit 1, front-right + rear-left on circuit 2). If one circuit fails, the other circuit still provides approximately 50-60% braking on the remaining wheels. Dual-circuit master cylinders are required by ECE R13-H §5.2.1 for all vehicles above 3.5T GVWR (N2, N3, M2, M3 categories) and for all vehicles with hydraulic brakes. (3) For OEM truck applications above 3.5T GVWR, dual-circuit master cylinders are mandatory. The diagonal split configuration is the most common, but some OEMs use front-rear split (front circuit + rear circuit) which provides 70-80% braking on the front wheels if the rear circuit fails, or vice versa.
Q3: Can I use a larger bore master cylinder to get more braking force?
No, you cannot simply use a larger bore master cylinder to get more braking force because the brake system is a closed hydraulic system with pressure equilibrium. The relationship is: Pressure = Pedal Force / (Bore Area × Pedal Ratio × Booster Ratio). A larger bore master cylinder requires more pedal force to generate the same line pressure because the same pedal force is distributed over a larger piston area. Specifically, doubling the bore diameter quadruples the piston area, which means the pedal force must quadruple to generate the same pressure. For example, going from a 7/8 inch bore (0.60 in² area) to a 1-inch bore (0.79 in² area) requires 31% more pedal force to generate the same line pressure. The practical effect of a larger bore is: (1) lower line pressure for the same pedal force, (2) more brake fluid displacement per pedal stroke (which means longer pedal stroke for the same caliper piston movement), (3) potentially softer pedal feel. The 3 effects are usually undesirable in truck applications where drivers expect firm pedal feel and quick response. The correct approach is to size the bore to the GVWR per SAE J1601, not to oversize the bore.
Q4: What brake fluid should I use with my master cylinder?
The brake fluid specification for a master cylinder depends on the seal material and the operating temperature range. The 3 common brake fluid specifications per SAE J1703 / FMVSS 116 / ISO 4925 are: (1) DOT 3 (glycol-ether based) — minimum dry boiling point 205°C, minimum wet boiling point 140°C; compatible with EPDM and natural rubber seals; suitable for light commercial vehicles with moderate braking duty, (2) DOT 4 (glycol-ether-borate based) — minimum dry boiling point 230°C, minimum wet boiling point 155°C; compatible with EPDM seals; suitable for heavy commercial vehicles with high braking duty including trucks above 12T GVWR, (3) DOT 5.1 (glycol-ether-borate based) — minimum dry boiling point 260°C, minimum wet boiling point 180°C; compatible with EPDM seals; suitable for high-performance and severe-duty applications including racing trucks and military vehicles. DOT 5 (silicone-based) is NOT compatible with glycol-based fluids and should not be mixed. For Shaoxing Fangjie master cylinders, the standard seal material is EPDM which is compatible with DOT 3, DOT 4, and DOT 5.1. The factory fill for OEM supply is typically DOT 4 for heavy commercial vehicle applications.
Q5: How do I troubleshoot a soft brake pedal in a truck?
A soft brake pedal in a truck can be caused by 7 issues, ranked by frequency: (1) Air in the brake system (most common) — bleed the brake system per OEM procedure, typically starting at the wheel farthest from the master cylinder and working toward the closest, (2) Master cylinder internal seal failure — the primary or secondary cup seal is worn or damaged, allowing fluid to bypass the piston; replace the master cylinder, (3) Brake fluid leak — check all brake lines, calipers, wheel cylinders, and the master cylinder body for fluid leakage; repair or replace as needed, (4) Brake hose expansion — the rubber brake hoses have internal degradation and expand under pressure, giving a soft pedal feel; replace the brake hoses (typically every 4-6 years or 200,000-300,000 km), (5) Booster failure — the vacuum booster is not providing adequate boost, requiring more pedal force to generate the same pressure; check the booster vacuum line, check valve, and booster diaphragm; replace the booster if necessary, (6) Caliper piston seal failure — the caliper piston seal is worn, allowing fluid to bypass; rebuild or replace the caliper, (7) Wrong master cylinder bore — the bore is too large for the GVWR, giving a soft pedal feel due to lower line pressure; verify the bore diameter per SAE J1601 guidelines. The 7 issues should be diagnosed in the order listed, with the most common and least expensive (air bleeding) addressed first.
Q6: What is the typical master cylinder replacement interval for a commercial truck?
The typical master cylinder replacement interval for a commercial truck is 5-8 years or 400,000-600,000 km, whichever comes first, under normal operating conditions. The replacement interval is determined by 3 factors: (1) Internal seal wear — the primary cup seal and the secondary cup seal wear gradually with each brake application; the seal material (typically EPDM) has a fatigue life of approximately 2-3 million brake cycles, which corresponds to 5-8 years of typical commercial truck operation, (2) Brake fluid contamination — over time, brake fluid absorbs moisture from the atmosphere (DOT 3/4/5.1 fluids are hygroscopic), which reduces the boiling point and accelerates internal corrosion; brake fluid should be flushed and replaced every 2 years regardless of master cylinder condition, (3) Cylinder bore wear — the aluminum alloy bore gradually wears from piston movement, particularly if the brake fluid is contaminated or if the seals fail; bore wear above 0.05 mm (0.002 inch) typically requires master cylinder replacement. Shaoxing Fangjie Auto Accessory Co., Ltd. manufactures master cylinders with hardened aluminum alloy bore (anodized surface treatment) and EPDM seals rated for 2-3 million brake cycles. We recommend preventive replacement at the 5-year / 400,000 km mark for trucks operating in severe-duty conditions (high braking frequency, mountainous terrain, hot climates). For light-duty trucks in mild conditions, the replacement interval can extend to 8 years / 600,000 km.
About the Author
I am Elian Zhou, the Export Manager at Shaoxing Fangjie Auto Accessory Co., Ltd., a truck brake system components manufacturer with over 20 years of OEM production experience since 2003. Based in Shaoxing, Zhejiang, I work daily with our 100+ workforce and 10-person foreign trade team to supply brake calipers, slack adjusters, solenoid valves, and brake chambers to aftermarket distributors across Europe, Southeast Asia, and the Middle East. I regularly visit the factory floor and share production process insights — from automatic slack adjuster assembly to CNC machining of caliper housings — on my YouTube channel: @ElianZhou-y6q4i.
For OEM tender specifications on brake master cylinders or to request ECE R13-H compliance documentation for your truck GVWR band, visit our clutch master cylinder product page. Connect with me on YouTube for production process videos covering CNC machining of caliper housings and master cylinder assembly.
Post time: Aug-14-2026