Turn pedal effort into hydraulic braking pressure with the Dorman First Stop Brake Master Cylinder M39578. It is a direct-fit application for many vehicles, among them the 1985-1995 Chevrolet G20, 1985-1995 Chevrolet G10 and 1985-1995 GMC G1500; see the Buyer's Guide tab for the full list. Each application uses one unit.
Dorman precision-engineers this master cylinder to replicate the original unit's design, function and performance.
A soft or sinking pedal, fluid seeping at the master cylinder, or a lit brake warning light can be signs this part may need replacing. These symptoms can have other causes, so diagnose the brake system first, and follow the vehicle's service procedure when installing it.
Specifications: Two outlets, 1/2-20 rearward outlet size, and the reservoir is included. Mounting hardware and a sensor are not included, so consult the vehicle service information for the correct fasteners and whether they may be reused. Package contents: one master cylinder. Country of origin: China.
Which vehicles does the Dorman M39578 master cylinder fit?
It fits many vehicles, among them the 1985-1995 Chevrolet G20, 1985-1995 Chevrolet G10 and 1985-1995 GMC G1500. See the Buyer's Guide tab for the full list.
Does the M39578 come with a reservoir?
Yes, the reservoir is included. Mounting hardware and a sensor are not included, so check the vehicle service information for the correct fasteners and whether the originals may be reused.
What is this master cylinder made of?
The master cylinder material is aluminum. All of its rubber components are made of a high-quality EPDM compound that resists glycol-based brake fluid.
What are signs a brake master cylinder may need replacing?
A soft or sinking brake pedal, fluid leaking at the master cylinder, or a brake warning light can be signs the master cylinder may need replacing. These can have other causes, so diagnose the brake system before replacing it.
How many outlets does the M39578 have?
It has two outlets, and the rearward outlet size is 1/2-20. Compare these with your original unit's brake line connections before installing.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
