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ACDelco 18M321 Brake Master Cylinder

ACDelco 18M321 Brake Master Cylinder Image 3

ACDelco 18M321 Brake Master Cylinder Image 4

ACDelco 18M321 Brake Master Cylinder Image 5

ACDelco 18M321 Brake Master Cylinder Image 6

ACDelco 18M321 Brake Master Cylinder Image 7

ACDelco 18M321 Brake Master Cylinder Image 8


Brand:	ACDelco
Part Number:	18M321
UPC:	00036666698084
Weight:	2.97 lbs
Condition:	New

Availability:	0 in Stock
	OUT OF STOCK

Product Information

Description:

MASTER CYL (B)

ACDelco 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

Features and Benefits:

Cast iron and aluminum specifications; no extra stress on the brake boosting mounting
Geometrical tolerance ensures that the body and plastic reservoir match for a proper fit
Meets the brake performance requirements of SAE J1153 and J1154 testing, providing reliability and quality
Piston assembly and return spring help to prevent brake drag, which can cause premature brake pad wear
Pressure tested to ensure safe and confident braking

Specifications:

Bleeder Hoses Included:

Yes

Bore Size:

24.000 mm

Brake Booster Included:

Height (in):

5.6 in

Length (in):

11.3 in

Master Cylinder Bore Diameter:

0.94488189 in.

Master Cylinder Bore Diameter:

24 mm

Master Cylinder Cap Included:

Yes

Master Cylinder Material:

Aluminum

Measurements:

24.0 mm Cylinder Bore

Mounting Bracket Included:

Mounting Hole Diameter:

0.433 in.

Mounting Hole Quantity:

Port Quantity:

Primary Outlet Thread Diameter:

12 mm

Programming Required:

Push Rod Included:

Reservoir Included:

Yes

Secondary Outlet Thread Diameter:

10 mm

Weight (lb):

2.97 lb

Width (in):

7.7 in

Features and Benefits:

– Calipers and wheel cylinders should be checked every brake inspection and serviced or replaced as required.
– Check brake fluid level at every oil change. Replace fluid according to owner's manual recommendations.
– Check the thickness of your brake pads.
– Inspect the brake lines for rust, punctures, or visible leaks (You may be able to do this, but consult a qualified technician if necessary).
– Inspection of brake lining and pads for wear or contamination by brake fluid or grease.
– Inspection of the brake hoses for brittleness or cracking.
– Inspection of wheel bearings and grease seals.
– Parking brake adjustments (as needed).
The following inspections and maintenance procedures can help prevent potential brake problems:
The following should be conducted by a qualified technician:

Specifications:

Country of Origin:

Select a vehicle to narrow ACDelco 18M321 Brake Master Cylinder fitment info!

Last Updated: 03/09/2024

Years

Vehicle

Per Vehicle

Fit Notes

Fitment Notes

1993

Buick Century

2.2L L4 Gas OHV,
3.3L V6 Gas OHV

1 Professional
Coupe
2 Doors

Buick Century

2.2L L4 Gas OHV,
3.3L V6 Gas OHV Professional
Coupe
2 Doors

1 Per Vehicle

1993

Buick Century

2.2L L4 Gas OHV,
3.3L V6 Gas OHV

1 Professional
Sedan
4 Doors

Buick Century

2.2L L4 Gas OHV,
3.3L V6 Gas OHV Professional
Sedan
4 Doors

1 Per Vehicle

Buick Century

3.3L V6 Gas OHV

1 Professional
GM Brake Code JA2
Coupe
2 Doors

Buick Century

3.3L V6 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

3.3L V6 Gas OHV

1 Professional
GM Brake Code JA2
Sedan
4 Doors

Buick Century

3.3L V6 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Century

2.5L L4 Gas OHV

1 Professional
GM Brake Code JA2
Coupe
2 Doors

Buick Century

2.5L L4 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

2.5L L4 Gas OHV

1 Professional
GM Brake Code JA2
Sedan
4 Doors

Buick Century

2.5L L4 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Century

2.8L V6 Gas OHV

1 Professional
GM Brake Code JA2
Coupe
2 Doors

Buick Century

2.8L V6 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

2.8L V6 Gas OHV

1 Professional
GM Brake Code JA2
Sedan
4 Doors

Buick Century

2.8L V6 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Century

3.8L V6 Gas OHV

1 Professional
GM Brake Code JA2
Coupe
2 Doors

Buick Century

3.8L V6 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

3.8L V6 Gas OHV

1 Professional
GM Brake Code JA2
Sedan
4 Doors

Buick Century

3.8L V6 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

1988

Buick Skyhawk

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC

1 Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

Buick Skyhawk

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

1 Per Vehicle

1987

Buick Skyhawk

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC,
2.0L L4 Gas SOHC Turbo

1 Professional

Buick Skyhawk

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC,
2.0L L4 Gas SOHC Turbo Professional

1 Per Vehicle

1988

Buick Skylark

2.3L L4 Gas DOHC,
2.5L L4 Gas OHV,
3.0L V6 Gas OHV

1 Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

Buick Skylark

2.3L L4 Gas DOHC,
2.5L L4 Gas OHV,
3.0L V6 Gas OHV Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

1 Per Vehicle

1987

Buick Skylark

2.5L L4 Gas OHV,
3.0L V6 Gas OHV

1 Professional

Buick Skylark

2.5L L4 Gas OHV,
3.0L V6 Gas OHV Professional

1 Per Vehicle

1987

ACDelco 18M321 Brake Master Cylinder

Product Information

Description:

Features and Benefits:

Specifications:

Features and Benefits:

Specifications:

Select a vehicle to narrow ACDelco 18M321 Brake Master Cylinder fitment info!

Buick Century 2.2L L4 Gas OHV,3.3L V6 Gas OHV

1

ProfessionalCoupe2 Doors

Buick Century

2.2L L4 Gas OHV,3.3L V6 Gas OHV ProfessionalCoupe2 Doors 1 Per Vehicle

Buick Century 2.2L L4 Gas OHV,3.3L V6 Gas OHV

1

ProfessionalSedan4 Doors

Buick Century

2.2L L4 Gas OHV,3.3L V6 Gas OHV ProfessionalSedan4 Doors 1 Per Vehicle

Buick Century 3.3L V6 Gas OHV

1

ProfessionalGM Brake Code JA2Coupe2 Doors

Buick Century

3.3L V6 Gas OHV ProfessionalGM Brake Code JA2Coupe2 Doors 1 Per Vehicle

Buick Century 3.3L V6 Gas OHV

1

ProfessionalGM Brake Code JA2Sedan4 Doors

Buick Century

3.3L V6 Gas OHV ProfessionalGM Brake Code JA2Sedan4 Doors 1 Per Vehicle

Buick Century 2.5L L4 Gas OHV

1

ProfessionalGM Brake Code JA2Coupe2 Doors

Buick Century

2.5L L4 Gas OHV ProfessionalGM Brake Code JA2Coupe2 Doors 1 Per Vehicle

Buick Century 2.5L L4 Gas OHV

1

ProfessionalGM Brake Code JA2Sedan4 Doors

Buick Century

2.5L L4 Gas OHV ProfessionalGM Brake Code JA2Sedan4 Doors 1 Per Vehicle

Buick Century 2.8L V6 Gas OHV

1

ProfessionalGM Brake Code JA2Coupe2 Doors

Buick Century

2.8L V6 Gas OHV ProfessionalGM Brake Code JA2Coupe2 Doors 1 Per Vehicle

Buick Century 2.8L V6 Gas OHV

1

ProfessionalGM Brake Code JA2Sedan4 Doors

Buick Century

2.8L V6 Gas OHV ProfessionalGM Brake Code JA2Sedan4 Doors 1 Per Vehicle

Buick Century 3.8L V6 Gas OHV

1

ProfessionalGM Brake Code JA2Coupe2 Doors

Buick Century

3.8L V6 Gas OHV ProfessionalGM Brake Code JA2Coupe2 Doors 1 Per Vehicle

Buick Century 3.8L V6 Gas OHV

1

ProfessionalGM Brake Code JA2Sedan4 Doors

Buick Century

3.8L V6 Gas OHV ProfessionalGM Brake Code JA2Sedan4 Doors 1 Per Vehicle

Buick Skyhawk 2.0L L4 Gas OHV,2.0L L4 Gas SOHC

1

Professionalwith LF Stamped on Booster Master Cylinder Labeled DL

Buick Skyhawk

2.0L L4 Gas OHV,2.0L L4 Gas SOHC Professionalwith LF Stamped on Booster Master Cylinder Labeled DL 1 Per Vehicle

Buick Skyhawk 2.0L L4 Gas OHV,2.0L L4 Gas SOHC,2.0L L4 Gas SOHC Turbo

1

Professional

Buick Skyhawk

2.0L L4 Gas OHV,2.0L L4 Gas SOHC,2.0L L4 Gas SOHC Turbo Professional 1 Per Vehicle

Buick Skylark 2.3L L4 Gas DOHC,2.5L L4 Gas OHV,3.0L V6 Gas OHV

1

Professionalwith LF Stamped on Booster Master Cylinder Labeled DL

Buick Skylark

2.3L L4 Gas DOHC,2.5L L4 Gas OHV,3.0L V6 Gas OHV Professionalwith LF Stamped on Booster Master Cylinder Labeled DL 1 Per Vehicle

Buick Skylark 2.5L L4 Gas OHV,3.0L V6 Gas OHV

1

Professional

Buick Skylark

Buick Century

2.2L L4 Gas OHV,
3.3L V6 Gas OHV

Professional
Coupe
2 Doors

2.2L L4 Gas OHV,
3.3L V6 Gas OHV Professional
Coupe
2 Doors

1 Per Vehicle

Buick Century

2.2L L4 Gas OHV,
3.3L V6 Gas OHV

Professional
Sedan
4 Doors

2.2L L4 Gas OHV,
3.3L V6 Gas OHV Professional
Sedan
4 Doors

1 Per Vehicle

Buick Century

3.3L V6 Gas OHV

Professional
GM Brake Code JA2
Coupe
2 Doors

3.3L V6 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

3.3L V6 Gas OHV

Professional
GM Brake Code JA2
Sedan
4 Doors

3.3L V6 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Century

2.5L L4 Gas OHV

Professional
GM Brake Code JA2
Coupe
2 Doors

2.5L L4 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

2.5L L4 Gas OHV

Professional
GM Brake Code JA2
Sedan
4 Doors

2.5L L4 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Century

2.8L V6 Gas OHV

Professional
GM Brake Code JA2
Coupe
2 Doors

2.8L V6 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

2.8L V6 Gas OHV

Professional
GM Brake Code JA2
Sedan
4 Doors

2.8L V6 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Century

3.8L V6 Gas OHV

Professional
GM Brake Code JA2
Coupe
2 Doors

3.8L V6 Gas OHV Professional
GM Brake Code JA2
Coupe
2 Doors

1 Per Vehicle

Buick Century

3.8L V6 Gas OHV

Professional
GM Brake Code JA2
Sedan
4 Doors

3.8L V6 Gas OHV Professional
GM Brake Code JA2
Sedan
4 Doors

1 Per Vehicle

Buick Skyhawk

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC

Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

1 Per Vehicle

Buick Skyhawk

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC,
2.0L L4 Gas SOHC Turbo

2.0L L4 Gas OHV,
2.0L L4 Gas SOHC,
2.0L L4 Gas SOHC Turbo Professional

1 Per Vehicle

Buick Skylark

2.3L L4 Gas DOHC,
2.5L L4 Gas OHV,
3.0L V6 Gas OHV

Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

2.3L L4 Gas DOHC,
2.5L L4 Gas OHV,
3.0L V6 Gas OHV Professional
with LF Stamped on Booster
Master Cylinder Labeled DL

1 Per Vehicle

Buick Skylark

2.5L L4 Gas OHV,
3.0L V6 Gas OHV