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1972 Honda CB500K Master Cylinder Service Parts

Master cylinder service on a 1972 CB500K can mean rebuilding the existing unit, replacing the assembly or renewing reservoir parts. Identify the installed cylinder first. The kit, diaphragm, cap and 14mm assembly have different contents; none should be assumed to include every other item.

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Currently viewing Master Cylinder & Rebuild Parts

Honda motorcycle parts

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Honda CB750 CB550 CB400F front master cylinder kit 45530-377-305

Honda CB Front Master Cylinder Rebuild Kit ~ Replaces 45530-377-305

$37.95 USD
08-0215
Rebuild your early SOHC CB's front master cylinder with this Front Brake Master Cylinder Rebuild Kit, replacing OEM #45530-377-305. Made in Japan. Fits the...
Honda CB750 CB550 CB500 master cylinder rubber boot 45522-300-010

Honda CB Master Cylinder Rubber Boot ~ Replaces 45522-300-010

$9.95 USD
33-0003
Replace your master cylinder rubber boot with this Master Cylinder Rubber Boot, which attaches where the brake hose joins the master cylinder. Replaces OEM...
New
Honda CB750 CB550 CB400F front master cylinder assembly 5 8 in.

Honda CB Front Master Cylinder Assembly ~ 5/8 in.

$99.95 USD
08-0253
Drop in a factory-look master cylinder with a performance piston size using this Front Brake Master Cylinder Assembly. Black body with silver lever, custom-manufactured...
Honda CB750 CB550 CB400F master cylinder diaphragm 45520-300-000

Honda CB Master Cylinder Reservoir Diaphragm ~ Replaces 45520-300-000

$10.95 USD
08-0282
Replace a hardened or torn master cylinder diaphragm with this Master Cylinder Reservoir Diaphragm, replacing OEM #45520-300-000. Exceptional range of applications, fits FRONT master...
Honda CB750 CB550 CB500 CB400 CB350 master cylinder damper set

Honda CB Master Cylinder Damper Set

$6.95 USD
73-0841
Replace your master cylinder damper with this Master Cylinder Damper Set. Includes brake master cylinder rubber damper, plate, and washer. This set is often...
New
Honda CB750 CB550 CB400F front master cylinder assembly 14mm

Honda CB Front Master Cylinder Assembly ~ 14mm

$99.95 USD
08-0269
Restore strong and consistent braking performance with this Front Brake Master Cylinder Assembly, designed as a high-quality replacement for many classic Honda models. This...
Honda CB1000 CB900 master cylinder reservoir cap plastic o-ring 45521-MJ6-006

Honda CB Master Cylinder Reservoir Cap Plastic O-Ring ~ Replaces 45521-MJ6-006

$4.95 USD
29-0062
Replace your master cylinder cap O-ring with this Master Cylinder Reservoir Cap Plastic O-Ring, replacing OEM #45521-MJ6-006.Key Features• Master cylinder reservoir cap O-ring• Plastic•...
Honda CB1100 CB1000 CB900 master cylinder reservoir cap 45513-341-771

Honda CB Master Cylinder Reservoir Cap ~ Replaces 45513-341-771

$39.95 USD
29-0054
Restore your master cylinder cap with this Master Cylinder Cap with Plastic O-Ring, replacing OEM #45513-341-771. This original style was discontinued long ago by...
Universal Honda-type front master cylinder assembly 13mm

Universal Honda-Type Front Master Cylinder Assembly ~ 13mm

$84.95 USD
08-0262
Upgrade to a universal front master cylinder assembly with this Honda-type unit. Complete with lever, banjo bolt, banjo bolt washers, and brake light switch,...
Sold out
Honda CB750 CB650 CB550 replacement brake lever for master cylinder

Honda CB Replacement Brake Lever for Master Cylinder 08-0262

$9.95 USD
08-0430
Replace the brake lever on the #08-0262 Master Cylinder Assembly specifically with this Brake Lever. Designed for this particular master cylinder.Key Features• Replacement brake...
Honda CB1100 CB1000 CB900 master cylinder reservoir cap 43513-MJ6-006

Honda CB Master Cylinder Reservoir Cap ~ Replaces 43513-MJ6-006

$23.45 USD
29-0080
Replace your master cylinder reservoir cap with this Master Cylinder Reservoir Cap with Diaphragm, round OEM thread-on type. Cap replaces OEM #43513-MJ6-006, diaphragm replaces...
Magura universal front master cylinder assembly 13mm

Magura Universal Front Master Cylinder Assembly ~ 13mm

$259.00 USD
08-0250
Build a custom front brake setup with this Magura Universal Front Brake Master Cylinder. Features a 13mm piston diameter, 12mm stroke, and a threaded...
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1972 Honda CB500K · Master Cylinder Service Buying guide

Decide which part of the master cylinder needs attention

The internal service kit references 45530-377-305. The featured replacement assembly specifies a 14mm piston, while reservoir diaphragm and cap are separate parts. Confirm the existing unit and required specification before choosing between these repair paths.

Parts to consider

Honda CB Front Master Cylinder Rebuild Kit ~ Replaces 45530-377-305 Internal master cylinder service kitJapanese-made kit for one compatible front master cylinder; reference 45530-377-305.View part Honda CB Front Master Cylinder Assembly ~ 14mm Assembly with 14mm pistonBlack body and silver lever; confirm piston-size compatibility with the installed system.View part Honda CB Master Cylinder Reservoir Diaphragm ~ Replaces 45520-300-000 Rubber reservoir diaphragmSeparate reservoir part replacing Honda reference 45520-300-000.View part

Related parts: Reproduction cap and plastic O-ring

A reservoir repair is different from an internal rebuild

Inspect the cap, diaphragm and reservoir fit before choosing replacement reservoir pieces. The cap’s stated plastic O-ring is not the rubber diaphragm. The internal rebuild kit addresses a compatible cylinder’s service parts, so it should not be ordered on the assumption that it renews all reservoir hardware.

Compare specification before selecting a complete unit

The 14mm assembly is listed for the CB500K but asks the buyer to confirm the original piston size. Other offered assemblies have different specifications. Compare the system on the motorcycle rather than choosing by finish or an assumed braking improvement, especially after controls or brake equipment have changed.

Common questions

How do I compare the 14 mm assembly with an altered brake setup?

The replacement specifies a 14 mm piston, black body and silver lever. The source asks buyers to confirm the original piston size. Identify the cylinder and hydraulic system fitted now; listed CB500K fitment does not establish compatibility with every changed arrangement.

Which references separate the cap seal from the reservoir diaphragm?

Cap 45513-341-771 includes a plastic O-ring, while diaphragm 45520-300-000 is separately listed. Compare the installed reservoir and damaged piece before ordering. Replacing an original cylinder with another assembly can change which cap and diaphragm references match.

What application must match the internal master-cylinder kit?

The Japanese-made kit references Honda 45530-377-305 and supplies internal service parts for one compatible front cylinder. Match the installed unit before buying. The package is not described as supplying an entire replacement cylinder body, lever and reservoir assembly.

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Send your model and year, plus photos of your existing part and any changes to the original setup.

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