Deliver firm, dependable pedal feel with the Dorman - First Stop Brake Master Cylinder (M630274). This master cylinder converts brake-pedal force into the hydraulic pressure that pushes fluid through the brake circuits, and it drops in for a wide range of medium- and heavy-duty trucks — including the 2003-2009 Chevrolet C4500/C5500/C6500/C7500 Kodiak, 2003-2009 GMC C4500/C5500/C6500/C7500 Topkick, 2003-2009 Isuzu FTR and FVR, plus earlier Chevrolet and GMC models. See the Buyer's Guide tab for the full list of 21 applications.
- 100% new: made entirely of new materials, not remanufactured.
- Cast iron housing: constructed to match the casting material of the original part for similar performance.
- Durable design: all rubber components use a high-quality EPDM compound for resistance to glycol-based brake fluid.
- Built to standard: made to meet rigorous SAE International standards.
It features a 2-inch bore, two outlets, and a secondary outlet thread diameter of 1/2-20. The reservoir and sensor are included; mounting hardware is not. Country of origin: China. If a failed master cylinder is the cause of a sinking or spongy pedal, this replaces it.
Interchange: 13-8042 · 138042 · 10-8041 · 108041 · 130.82007 · 13082007 · 15007799 · 15142243 · 19301986 · 8150077990 · 8151422430 · 8193019860 · F141605 · MC141605 · Manufacturer part number M630274
This part cross-references / interchanges with the following part numbers:
Frequently Asked Questions
What does this brake master cylinder do?
It converts the force of your brake pedal into hydraulic pressure, sending brake fluid through the circuits to apply the brakes. It is designed to match the design and function of the original unit on the listed vehicles.
What are signs the master cylinder may need replacing?
A pedal that slowly sinks under steady pressure, feels spongy, or fluid leaking internally or externally can be signs. Have the brake system diagnosed first, since other components can cause similar symptoms.
Does it include a reservoir and sensor?
Yes. Per the catalog, both the reservoir and a sensor are included. It has two outlets and a secondary outlet thread diameter of 1/2-20.
Is mounting hardware included?
No, mounting hardware is not included. Consult the vehicle service information for the correct fasteners and whether they may be reused.
What is it made of?
The cylinder housing is cast iron, constructed to match the casting material of the original part, and all rubber components use an EPDM compound for resistance to glycol-based brake fluid.