Dorman M631066 brake master cylinder for the 2014-2018 Mazda 3 and other vehicles turns pedal force into hydraulic pressure for the brakes. This Dorman master cylinder is a new part from the First Stop line.
- Aluminum cylinder housing, matched to the casting material of the part it replaces
- All rubber components are EPDM compound for resistance to glycol-based brake fluid
- Made entirely of new materials
- Made to meet rigorous SAE International standards
Quick facts
- Part: Dorman M631066 brake master cylinder
- Fits: 2014-2018 Mazda 3 and other vehicles
- Material: Aluminum
- Condition: New
A brake pedal that feels soft or sinks can mean this master cylinder is worn, though a leaking brake caliper or a damaged brake line can also give a soft pedal.
Fits
It is a direct-fit brake master cylinder replacement for the 2014-2018 Mazda 3 and the 2016-2018 Mazda 3 Sport.
Specifications
Fit and size
- Quantity per vehicle: 1
- Mounting holes: 2
- Number of outlets: 2, flanged
- Bore diameter: 13/16 in
- Rearward outlet size: M12x1.0
- Primary outlet thread diameter: 12 mm
- Secondary outlet thread diameter: M12x1.0, pitch 1 mm
Build and materials
- Material: Aluminum
- Reservoir type: single
- Master cylinder cap: included
- Condition: New
- Country of origin: Taiwan
In the box
One master cylinder and one bleeder kit, with the cap included. This listing is one master cylinder; the 2014-2018 Mazda 3 and the 2016-2018 Mazda 3 Sport take one. The mounting hardware, gasket or seal, mounting bracket, reservoir, push rod and dust boot are not included; plan on new fasteners, since the old ones may not be reusable.
Interchange: 130.45429 · 355-80082 · 355-80084
NM55655 · BHY14340Z · MC146162
This part cross-references / interchanges with the following part numbers:
130.45429, 355-80082, 355-80084, NM55655, BHY14340Z, MC146162
Frequently Asked Questions
Is Dorman M631066 a 2014-2018 Mazda 3 master cylinder, and does it fit the 2016-2018 Mazda 3 Sport too?
Yes. Dorman M631066 fits the 2014-2018 Mazda 3 and the 2016-2018 Mazda 3 Sport, and each takes one.
Does this 2014-2018 Mazda 3 master cylinder replacement include the reservoir?
No. The reservoir is not included with Dorman M631066, but the master cylinder cap and a bleeder kit come with it.
What are the outlet threads on this Dorman brake master cylinder?
Dorman M631066 has two flanged outlets. The rearward and secondary outlets are M12x1.0, and the primary outlet thread diameter is 12 mm.
Can a sinking pedal mean Dorman M631066 needs replacing?
It can, and so can fluid around the cylinder body. Have the brakes inspected promptly by a shop rather than driving on a suspect master cylinder.
Are the rubber parts in this master cylinder made for brake fluid?
Yes. All rubber components are EPDM compound, which resists glycol-based brake fluid.
