Dorman - First Stop Brake Master Cylinder diamond t for 1940-1983 Trucks M661

Brake Master Cylinder for 1940-1983 Trucks from Dorman - First Stop used to replace worn or failing factory master cylinders.

Built to meet the manufacturer’s design intent for reliable service.

Key Features

• Precision-engineered to match original master cylinder design, function, and performance
• Made of high-quality materials
• Meets rigorous SAE International standards
• Fits 1940-1983 trucks
• Part number M661

Benefits

• Reliable braking performance comparable to OEM
• Reduced risk of brake failure
• Easy installation with direct-fit design
• Long-lasting durability
• Peace of mind knowing it meets SAE standards

Application

This part is for truck owners needing a reliable replacement master cylinder. Common use cases include restoring braking system after wear, replacing factory parts in older trucks, or upgrading to a more durable aftermarket component.

Fitment Notes

• Fits 1940-1983 trucks
• Compatible w/: Navistar: 130328H | Navistar: 48175HX | Navistar: 48175H | Navistar: 142907H | Navistar: 116154H | Navistar: 93681R91 | Diamond Reo: DX4731 | Diamond Reo: N1507 | Diamond Reo: DX5454 | Diamond Reo: N4507 | Diamond Reo: N2507 | Navistar: 57836H | White: 382056 | White: 395202 | White: C19028 | White: 371697 | White: 352445 | General Motors: 5473006 | Studebaker: 644752 | Mack: 8QE214

Why Choose Dorman - First Stop?

• Choosing Dorman aftermarket replacement parts is a smart way to restore your vehicle with confidence, thanks to a strong focus on fit, durability, and dependable performance. Dorman parts are engineered as direct-fit replacements designed to match OE form, fit, and function, helping ensure a smoother installation and reliable results. Built with quality materials and validated through testing, they’re made to stand up to daily driving demands and help reduce the risk of repeat repairs. For a long-lasting fix you can trust, Dorman delivers proven aftermarket solutions that keep your vehicle operating the way it should.

What’s in the Box

• Included items not specified by the manufacturer.

Item Dimensions

• Dimensions: 8.4in x 7.0in x 4.3in; Weight: 6.0lbs.