Turn brake-pedal effort into the hydraulic pressure that works your brakes with the Dorman - First Stop Brake Master Cylinder M390418. It drops in as a direct-fit replacement for the 1998-1999 Acura CL, 1998-2002 Honda Accord, 1998 Honda Odyssey, 1998-1999 Isuzu Oasis, 2001-2003 Acura CL, and 2002-2003 Acura TL (all engines). The master cylinder pressurizes brake fluid and sends it through its two outlets to the brake circuits; if a leaking or internally bypassing original cylinder is behind a low or sinking pedal, this replaces it.
- 100% new: built entirely from new materials, not remanufactured.
- Aluminum housing: constructed to match the casting material of the original part for similar performance.
- Fluid-resistant seals: rubber components use a high-quality EPDM compound to resist glycol-based brake fluid.
- Built to spec: made to meet rigorous SAE International standards.
It has a 1-inch bore and two outlets with M10 x 1.0 threads, and includes the reservoir and sensor. Mounting hardware is not included — consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: Taiwan. Manufacturer part number M390418.
Frequently Asked Questions
What does this brake master cylinder do?
It converts brake-pedal force into hydraulic pressure and routes fluid through its two outlets to the brake circuits. If a failing original cylinder is causing a low or sinking pedal, this replaces it.
Does it include a reservoir and sensor?
Yes. Per the catalog, both the reservoir and the sensor are included with the master cylinder.
Is mounting hardware included?
No. Consult the vehicle service information for the correct fasteners and whether they may be reused.
Which vehicles does it fit?
The 1998-1999 and 2001-2003 Acura CL, 2002-2003 Acura TL, 1998-2002 Honda Accord, 1998 Honda Odyssey, and 1998-1999 Isuzu Oasis (all engines). See the Buyer's Guide tab to confirm your vehicle.
What are the bore and outlet specs?
It has a 1-inch bore and two outlets with M10 x 1.0 threads. The housing is aluminum, built to match the original part's casting material.