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Please, add your first item to the wishlist

Select vehicle to confirm fitment

Brake Master Cylinder

PART#: 18M124
ACDelco

$57.95

In stock

Fitments
YearMakeModelSubmodelEngineFuel TypePositionNote
1981BuickCenturyLimited4.3V8GAS
1981BuickCenturyBase3.8V6GAS
1981BuickCenturyLimited3.8V6GAS
1981BuickCenturyBase4.3V8GAS
1981BuickCenturySport4.3V8GAS
1981BuickCenturySport3.8V6GAS
1981BuickCenturyEstate3.8V6GAS
1981BuickCenturyEstate4.3V8GAS
1981BuickRegalBase4.3V8GAS
1981BuickRegalLimited4.3V8GAS
1981BuickRegalBase3.8V6GAS
1981BuickRegalLimited3.8V6GAS
1981BuickRegalSport3.8V6GAS
1981BuickRivieraT-Type5.0V8GAS | Rear Brake Type: Drum;
1981BuickRivieraBase3.8V6GAS | Rear Brake Type: Drum;
1981BuickRivieraBase5.0V8GAS | Rear Brake Type: Drum;
1981BuickRivieraT-Type3.8V6GAS | Rear Brake Type: Drum;
1981BuickRivieraT-Type4.1V6GAS | Rear Brake Type: Drum;
1981BuickRivieraBase4.1V6GAS | Rear Brake Type: Drum;
1981ChevroletEl CaminoSS3.8V6GAS
1981ChevroletEl CaminoSS4.4V8GAS
1981ChevroletEl CaminoBase3.8V6GAS
1981ChevroletEl CaminoBase5.0V8GAS
1981ChevroletEl CaminoConquista4.4V8GAS
1981ChevroletEl CaminoBase4.4V8GAS
1981ChevroletEl CaminoBase3.8V6GAS
1981ChevroletEl CaminoRoyal Knight3.8V6GAS
1981ChevroletEl CaminoConquista3.8V6GAS
1981ChevroletEl CaminoRoyal Knight3.8V6GAS
1981ChevroletEl CaminoRoyal Knight4.4V8GAS
1981ChevroletEl CaminoRoyal Knight5.0V8GAS
1981ChevroletEl CaminoSS5.0V8GAS
1981ChevroletEl CaminoConquista5.0V8GAS
1981ChevroletEl CaminoConquista3.8V6GAS
1981ChevroletMalibuClassic5.0V8GAS
1981ChevroletMalibuClassic3.8V6GAS
1981ChevroletMalibuBase5.7V8GAS
1981ChevroletMalibuClassic Landau3.8V6GAS
1981ChevroletMalibuClassic Landau5.0V8GAS
1981ChevroletMalibuClassic4.4V8GAS
1981ChevroletMalibuBase5.0V8GAS
1981ChevroletMalibuBase3.8V6GAS
1981ChevroletMalibuClassic Landau3.8V6GAS
1981ChevroletMalibuBase4.4V8GAS
1981ChevroletMalibuClassic3.8V6GAS
1981ChevroletMalibuBase3.8V6GAS
1981ChevroletMalibuClassic Landau4.4V8GAS
1981ChevroletMonte CarloBase3.8V6GAS
1981ChevroletMonte CarloLandau3.8V6GAS
1981ChevroletMonte CarloBase4.4V8GAS
1981ChevroletMonte CarloLandau5.0V8GAS
1981ChevroletMonte CarloBase3.8V6GAS
1981ChevroletMonte CarloLandau4.4V8GAS
1981ChevroletMonte CarloLandau3.8V6GAS
1981ChevroletMonte CarloBase5.0V8GAS
1981GMCCaballeroRoyal Knight3.8V6GAS
1981GMCCaballeroConquista3.8V6GAS
1981GMCCaballeroAmarillo3.8V6GAS
1981GMCCaballeroDiablo4.4V8GAS
1981GMCCaballeroBase3.8V6GAS
1981GMCCaballeroBase5.0V8GAS
1981GMCCaballeroDiablo3.8V6GAS
1981GMCCaballeroConquista4.4V8GAS
1981GMCCaballeroBase3.8V6GAS
1981GMCCaballeroRoyal Knight3.8V6GAS
1981GMCCaballeroRoyal Knight4.4V8GAS
1981GMCCaballeroAmarillo4.4V8GAS
1981GMCCaballeroAmarillo3.8V6GAS
1981GMCCaballeroDiablo3.8V6GAS
1981GMCCaballeroDiablo5.0V8GAS
1981GMCCaballeroConquista5.0V8GAS
1981GMCCaballeroAmarillo5.0V8GAS
1981GMCCaballeroBase4.4V8GAS
1981GMCCaballeroConquista3.8V6GAS
1981GMCCaballeroRoyal Knight5.0V8GAS
1981OldsmobileCutlassLS4.3V8GAS
1981OldsmobileCutlassLS3.8V6GAS
1981OldsmobileCutlassBrougham4.3V8GAS
1981OldsmobileCutlassBrougham3.8V6GAS
1981OldsmobileCutlass CalaisBase3.8V6GAS
1981OldsmobileCutlass CalaisBase4.3V8GAS
1981OldsmobileCutlass CruiserBrougham4.3V8GAS
1981OldsmobileCutlass CruiserBrougham3.8V6GAS
1981OldsmobileCutlass CruiserBase5.0V8GAS
1981OldsmobileCutlass CruiserBase4.3V8GAS
1981OldsmobileCutlass CruiserBase3.8V6GAS
1981OldsmobileCutlass CruiserBrougham5.0V8GAS
1981OldsmobileCutlass SupremeBase3.8V6GAS
1981OldsmobileCutlass SupremeLS4.3V8GAS
1981OldsmobileCutlass SupremeLS3.8V6GAS
1981OldsmobileCutlass SupremeBrougham4.3V8GAS
1981OldsmobileCutlass SupremeBrougham3.8V6GAS
1981OldsmobileCutlass SupremeBase4.3V8GAS
1981OldsmobileToronadoBrougham5.0V8GAS | Rear Brake Type: Drum;
1981OldsmobileToronadoXSC5.0V8GAS | Rear Brake Type: Drum;
1981OldsmobileToronadoBrougham4.1V6GAS | Rear Brake Type: Drum;
1981PontiacGrand LeMansSafari4.9V8GAS
1981PontiacGrand LeMansBase4.3V8GAS
1981PontiacGrand LeMansSafari4.3V8GAS
1981PontiacGrand LeMansBase3.8V6GAS
1981PontiacGrand LeMansSafari3.8V6GAS
1981PontiacGrand PrixBrougham4.3V8GAS
1981PontiacGrand PrixBrougham3.8V6GAS
1981PontiacGrand PrixLJ4.3V8GAS
1981PontiacGrand PrixLJ3.8V6GAS
1981PontiacGrand PrixBase4.3V8GAS
1981PontiacGrand PrixBase3.8V6GAS
1981PontiacLeMansSafari3.8V6GAS
1981PontiacLeMansBase4.3V8GAS
1981PontiacLeMansBase3.8V6GAS
1981PontiacLeMansSafari4.3V8GAS
1981PontiacLeMansSafari4.9V8GAS
1980BuickRivieraS3.8V6GAS | Rear Brake Type: Drum;
1980BuickRivieraBase3.8V6GAS | Rear Brake Type: Drum;
1980BuickRivieraS5.7V8GAS | Rear Brake Type: Drum;
1980BuickRivieraS5.0V8GAS | Rear Brake Type: Drum;
1980BuickRivieraBase5.0V8GAS | Rear Brake Type: Drum;
1980BuickRivieraBase5.7V8GAS | Rear Brake Type: Drum;
1980OldsmobileToronadoXSC5.0V8GAS | Rear Brake Type: Drum;
1980OldsmobileToronadoBrougham5.0V8GAS | Rear Brake Type: Drum;
1980OldsmobileToronadoBrougham5.7V8GAS | Rear Brake Type: Drum;
1980OldsmobileToronadoXSC5.7V8GAS | Rear Brake Type: Drum;
1979BuickRivieraS3.8V6GAS | Rear Brake Type: Drum;
1979BuickRivieraBase5.7V8GAS | Rear Brake Type: Drum;
1979BuickRivieraS5.7V8GAS | Rear Brake Type: Drum;
1979OldsmobileToronadoBrougham5.7V8DIESEL | Rear Brake Type: Drum;
1979OldsmobileToronadoXSR5.7V8GAS | Rear Brake Type: Drum;
1979OldsmobileToronadoXSR5.7V8DIESEL | Rear Brake Type: Drum;
1979OldsmobileToronadoBrougham5.7V8GAS | Rear Brake Type: Drum;
About ACDelco

When it comes to top-notch auto parts, one brand that stands tall is ACDelco. Popular for its commitment to quality and innovation, ACDelco has been a trusted name in the automotive industry. At Newparts.com, we're proud to offer a wide selection of ACDelco auto parts, including ACDelco spark plugs, ACDelco alternators, and ACDelco air filters, and other ACDelco parts, all at discounted prices.

ACDelco spark plugs are engineered to deliver exceptional performance and reliability, ensuring optimal engine operation and fuel efficiency. Whether you're cruising down the highway or navigating city streets, you can trust ACDelco spark plugs to keep your engine firing on all cylinders.

When it comes to power generation, ACDelco alternators are second to none. Designed to withstand the challenges of daily driving, ACDelco alternators deliver consistent power output to keep your vehicle's electrical systems running smoothly. With ACDelco alternators from Newparts.com, you can count on reliable performance mile after mile.

In addition to spark plugs and alternators, we also offer a range of ACDelco air filters to help keep your engine breathing clean, fresh air. ACDelco air filters are designed to trap dirt, dust, and other contaminants, preventing them from entering your engine and causing damage. With a high-quality ACDelco air filter from Newparts.com, you can enjoy improved engine performance and extended engine life.

At Newparts.com, we understand that getting the right parts quickly is essential. That's why we offer fast shipping on all ACDelco auto parts, so you can get back on the road with confidence. Plus, with our discounted prices, you can save big on the parts you need to keep your vehicle running smoothly. In case you want to purchase parts by phone, feel free to call us at 855-505-2886 and our customer service team will help you out. 

Whether you're in need of spark plugs, alternators, air filters, or any other ACDelco auto parts, Newparts.com has you covered. Shop our selection today and experience the quality and reliability of ACDelco for yourself.

Specifications
Bleeder Hoses IncludedYes
Bore Size24.000
Brake Booster IncludedNo
FAQ - Answer 1No, but it is a good idea to inspect them for wear-out, cracking, leaking etc.
FAQ - Answer 2Yes, ACDelco also offers GM OE brake cylinders.
FAQ - Answer 3Yes, ACDelco Professional Brake Cylinders come with a 12 month / unlimited mile warranty.
FAQ - Question 1Do I have to replace all my brake parts when replacing my brake cylinder?
FAQ - Question 2Does ACDelco offer other grades of brake cylinders?
FAQ - Question 3Are these brake parts durable?
Features & Benefits - Bullet 1Meets the brake performance requirements of SAE J1153 and J1154 testing, providing reliability and quality
Features & Benefits - Bullet 2Pressure tested to ensure safe and confident braking
Features & Benefits - Bullet 3Cast iron and aluminum specifications; no extra stress on the brake boosting mounting
Features & Benefits - Bullet 4Geometrical tolerance ensures that the body and plastic reservoir match for a proper fit
Features & Benefits - Bullet 5Piston assembly and return spring help to prevent brake drag, which can cause premature brake pad wear
Good Maintenance Practices - Section 1 - Bullet 1Check brake fluid level at every oil change. Replace fluid according to owner's manual recommendations.
Good Maintenance Practices - Section 1 - Bullet 2Calipers and wheel cylinders should be checked every brake inspection and serviced or replaced as required.
Good Maintenance Practices - Section 1 - Bullet 3Inspect the brake lines for rust, punctures, or visible leaks (You may be able to do this, but consult a qualified technician if necessary).
Good Maintenance Practices - Section 1 - Bullet 4Check the thickness of your brake pads.
Good Maintenance Practices - Section 1 - HeaderThe following inspections and maintenance procedures can help prevent potential brake problems:
Good Maintenance Practices - Section 2 - Bullet 1Inspection of the brake hoses for brittleness or cracking.
Good Maintenance Practices - Section 2 - Bullet 2Inspection of brake lining and pads for wear or contamination by brake fluid or grease.
Good Maintenance Practices - Section 2 - Bullet 3Inspection of wheel bearings and grease seals.
Good Maintenance Practices - Section 2 - Bullet 4Parking brake adjustments (as needed).
Good Maintenance Practices - Section 2 - HeaderThe following should be conducted by a qualified technician:
Height (in)6.2
Length (in)8.4
Master Cylinder Bore Diameter0.94488189
Master Cylinder Bore Diameter24
Master Cylinder Cap IncludedYes
Master Cylinder MaterialIron
Measurements24.0 mm Cylinder Bore
Mounting Bracket IncludedNo
Mounting Hole Diameter0.423
Mounting Hole Quantity2
Port Quantity2
Primary Outlet Thread Diameter0.5625
Primary Outlet Thread Diameter14.287
Product DescriptionACDelco Professional Brake Master Cylinders use both aluminum and iron castings, making them a high quality replacement for many vehicles on the road today. These master cylinders contain both Ethylene Propylene (EPDM) and Styrene Butadiene (SBR) rubber components to provide superior resistance to heat, corrosion, and leakage. ACDelco Professional Brake Master Cylinders are ready to bench bleed and install right out of the box - no assembly required. These premium aftermarket replacement brake master cylinders are manufactured to meet your expectations for fit, form, and function. ⚠ WARNING: Cancer and Reproductive Harm - https://www.P65Warnings.ca.gov
Programming RequiredNo
Push Rod IncludedNo
Reservoir IncludedYes
Secondary Outlet Thread Diameter0.5
Secondary Outlet Thread Diameter12.7
Signs of Wear & Troubleshooting - Section 1 - Bullet 1Brake warning light is on.
Signs of Wear & Troubleshooting - Section 1 - Bullet 2Fluid spots beneath the car, indicating there may be a leak within the cylinder.
Signs of Wear & Troubleshooting - Section 1 - Bullet 3Difficulty stopping the vehicle.
Signs of Wear & Troubleshooting - Section 1 - Bullet 4A low or sinking brake pedal.
Signs of Wear & Troubleshooting - Section 1 - HeaderBrake cylinder signs of wear include:
Weight (lb)4.77
Width (in)6.2
Warranty
We offer a 2-year warranty on all parts that we sell. If the part fails within 2 years of purchase, please contact us for instructions to replace it. The warranty does not cover normal wear and tear or improper installation. On many parts, we also offer Extend product protection, which is a way to add up to 3 additional years for 5 total years of worry free coverage. Select your preferred term length and you're covered!
Delivery & Returns

Delivery Info

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Returns Info

Newparts.com offers a thirty (30) day return for refund for all items purchased through Newparts.com. To qualify for return and refund, all items must be new and in their original manufacturers box. To initiate a return, please contact our customer service. This information is only a summary. Complete shipping and return policy information can be found in our web site policies.

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