Convert brake pedal effort into the hydraulic pressure that applies your brakes with the Dorman First Stop Brake Master Cylinder M630836, a new unit precision-engineered to match the design, function and performance of the original master cylinder. It fits many vehicles, among them the 2011-2018 Audi A8 Quattro, 2013-2018 Audi S8 and 2013-2017 Audi A4 Allroad. See the "Vehicles it fits" section for the full list.
- Precise replacement: the aluminum cylinder housing is built to match the casting material of the original part and is intended to deliver similar performance.
- Durable design: every rubber component uses a high-quality EPDM compound that resists glycol-based brake fluid.
- 100% new: made entirely from new materials and intended as a durable replacement.
- Strict specifications: made to meet rigorous SAE International standards.
Specifications: 1 in bore diameter and two outlets. The secondary outlet thread diameter is M12 x 1.0, the rearward outlet size is M12 x 1.0, and the primary outlet thread pitch is 1 mm.
In the box: the master cylinder only. The reservoir, sensor and mounting hardware are not included, so transfer or replace them as directed by the vehicle service procedure. Consult the vehicle service information for installation and brake bleeding. Country of origin: China.
Signs a master cylinder may need replacing include a soft or sinking brake pedal and brake fluid leaking around the unit. Other brake faults can cause similar symptoms, so diagnose the cause before replacing. If the master cylinder is at fault, M630836 is designed to take its place.
Interchange: 100-2943 · 13-4028 · 11-3864 · 11-4028 · 130.33132 · 355-73017
1002943 · 134028 · 113864 · 114028 · 13033132 · 35573017 · MC391422 · 8K0611021 · 8K0611021B · R135789
This part cross-references / interchanges with the following part numbers:
100-2943, 13-4028, 11-3864, 11-4028, 130.33132, 355-73017, MC391422, 8K0611021, 8K0611021B, R135789
Frequently Asked Questions
Which vehicles does the Dorman M630836 brake master cylinder fit?
It fits many vehicles, including the 2011-2018 Audi A8 Quattro, 2013-2018 Audi S8 and 2013-2017 Audi A4 Allroad. Check the "Vehicles it fits" section for the full list.
What does a brake master cylinder do?
It converts brake pedal force into hydraulic pressure and sends brake fluid through its outlets to the brake lines. This unit has two outlets and a 1 in bore diameter.
Is the reservoir included?
No. The package contains the master cylinder only. The reservoir, sensor and mounting hardware are not included, so transfer or replace them as directed by the vehicle service procedure.
What are signs a master cylinder may need replacing?
Signs include a soft or sinking brake pedal and brake fluid leaking around the unit. Other brake faults can cause similar symptoms, so diagnose the cause first.
What is this master cylinder made of?
The cylinder housing is aluminum, and all rubber components are made of a high-quality EPDM compound that resists glycol-based brake fluid. It is made to meet SAE International standards.
