The best pit bike master cylinder depends on whether you need a front or rear replacement and whether its mounting dimensions match your bike. The WEIYINGSI right-hand unit is best for many 50cc–125cc front-brake applications; the VRWEARE pump is a fitment-focused option for 7/8-inch handlebars; and the rear-cylinder choices cover different Chinese pit bike sizes and setups. Check your original part’s measurements before ordering.
| Product | Best For | Key Fitment Detail |
|---|---|---|
| WEIYINGSI Right Brake Master Cylinder | Front-brake replacements | 7/8-inch bars; 10mm banjo bolt |
| VRWEARE Motorcycle Brake Pump | Measured universal-style replacements | 12.7mm bore; 10×1.25mm banjo |
| WEIYINGSI Rear Brake Master Cylinder | Selected 110cc–140cc pit bikes | Built-in reservoir |
| Rear Caliper and Master Cylinder Assembly | Complete rear-brake assemblies | 40–50mm adjustable bolt spacing |
| LOCOPOW Rear Brake Master Cylinder | Many Chinese 50cc–125cc bikes | 10mm banjo bolt |
WEIYINGSI Right Brake Master Cylinder
Best for: Riders replacing a right-hand front brake master cylinder on a compatible 50cc–125cc off-road bike. It is selected for its stated handlebar and banjo-bolt dimensions, plus its listed size range.
The assembly is designed for 7/8-inch handlebars and uses a 10mm banjo bolt. The product description lists compatibility with many 50cc, 70cc, 90cc, 110cc, and 125cc bikes. It also describes a heavy-duty pump body and nitrile rubber seals intended to withstand heat, oil, and low temperatures.
Check before buying: The seller advises confirming the oil-screw measurement on the existing brake pump. The listed fitment range does not guarantee compatibility with every bike in those engine sizes.
VRWEARE 7/8-Inch Brake Pump
Best for: Buyers who can compare the replacement’s measurements with an existing right-hand brake pump. It is selected because it specifies several useful dimensions instead of relying only on a broad vehicle list.
The unit is listed for 7/8-inch, or 22mm, handlebars. Its stated piston bore diameter is 12.7mm, and its banjo-bolt specification is 10×1.25mm. It also has an M10 rear-view-mirror hole. The description lists dirt pit bikes, ATVs, quads, mopeds, scooters, buggies, and go-karts as potential applications.
Check before buying: “Universal” does not mean every brake system will match. Confirm the bore, banjo-bolt thread, lever orientation, and handlebar size before choosing this pump.
WEIYINGSI Rear Brake Master Cylinder
Best for: Owners of a listed compatible Chinese 110cc, 125cc, or 140cc dirt pit bike who need a rear master-cylinder replacement. It is selected for its built-in reservoir and stated model-size range.
The product is described as a new aftermarket replacement with a built-in reservoir. The seller names Sunl, Pitster, and SSR among the potential applications. Because model names and engine sizes can include different brake configurations, compare the mounting points and connections with the original cylinder before ordering.
Installation note: The listing specifically says to bleed remaining air from the brake system after installation. Avoid choosing it based on engine size alone if the existing unit’s mounting or hydraulic connections differ.
Rear Caliper And Master Cylinder Assembly
Best for: Buyers replacing more than the master cylinder and seeking a rear hydraulic assembly that includes a caliper and brake pads. It is selected for its adjustable mounting spacing and listed cable length.
The assembly is described for various 125cc–250cc dirt bikes, with Apolo, Taotao, Coolster, SSR, and Thumpstar among the named brands. It has adjustable bolt spacing from 40mm to 50mm, a 630mm cable, and a 15mm axle hole. The listing also describes it for bikes with 16-inch to 18-inch rear wheels.
Check before buying: Confirm wheel size, axle-hole diameter, bolt spacing, and cable routing against your bike. The stated range does not establish a fit for every model from the listed brands.
LOCOPOW Rear Brake Master Cylinder
Best for: Owners seeking a rear master cylinder for many Chinese 50cc–125cc ATV, quad, or pit bike applications. It is selected for its broad stated size range and named model families.
The listing gives a 10mm banjo-bolt size and says the part suits bikes that meet the mounting-hole dimensions. It names Taotao, BMS, Roketa, Xpro, Apollo, SSR, Pitster, Piranha, Sunl, NST, and Kazuma among potential applications.
Check before buying: The listing does not provide a complete set of measurements for every mounting point. Compare the existing rear cylinder’s mounting holes and hydraulic connection before ordering.
Buying Guide: How To Choose A Pit Bike Master Cylinder
Do you need a front or rear cylinder?
Start by identifying the failed part’s location. The WEIYINGSI right-hand and VRWEARE products are brake pumps for handlebar use. The other options are described as rear master cylinders or rear brake assemblies. A rear assembly that includes a caliper and pads is a different replacement choice from a standalone master cylinder.
Which measurements should you compare?
- Handlebar diameter: The two handlebar-mounted options specify 7/8-inch or 22mm bars.
- Banjo-bolt size: Check both diameter and thread pitch. The VRWEARE listing specifies 10×1.25mm; other listings state 10mm without giving the same thread detail.
- Piston bore: The VRWEARE pump lists a 12.7mm bore. Match this measurement when the original specification is available.
- Mounting dimensions: Compare bolt spacing, hole size, axle hole, and cable length where applicable.
- Orientation and connections: Confirm that the replacement’s lever side and hydraulic line connection suit the original setup.
Should you choose by engine size or model name?
Use engine size and brand names as an initial filter, not as proof of fit. The listings describe broad applications, but pit bikes can have different brake parts within the same size or model family. Measurements from the original component provide a more reliable comparison.
What should you consider after installation?
Hydraulic brake work requires correct assembly and bleeding. One product listing explicitly instructs buyers to bleed air from the system after installation. If you cannot confirm the installation or achieve proper brake operation, have the system checked by a qualified mechanic before riding.
Frequently Asked Questions
Are all pit bike master cylinders interchangeable?
No. Handlebar size, bore diameter, banjo-bolt thread, mounting points, and front-or-rear configuration can differ. Compare the replacement with the original part.
Does a 10mm banjo bolt guarantee a fit?
No. The thread pitch, brake-line connection, and other dimensions must also match. A listing that states only 10mm may not provide enough information to confirm compatibility.
Can I choose a master cylinder using engine size alone?
No. Engine size is a useful starting point, but it does not confirm identical brake hardware. Verify the original cylinder’s measurements and mounting arrangement.
Does the rear brake assembly include more than a master cylinder?
The listed rear hydraulic assembly includes a caliper and brake pads as well as the master cylinder. Check its dimensions against the bike before purchasing.