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Honda CB750 CB550 CB400F master cylinder diaphragm 45520-300-000
Parts fiche reference for SKU 08-0282
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60-day returnsEligible unused parts Free ground shippingUSA & Canada over $50
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Honda CB750 CB550 CB400F master cylinder diaphragm 45520-300-000

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Load image into Gallery viewer, Honda CB750 CB550 CB400F master cylinder diaphragm 45520-300-000
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Honda CB Master Cylinder Reservoir Diaphragm ~ Replaces 45520-300-000

08-0282
$10.95 USD
In stock Usually ships the same or next business day
Check model fitment View fitment
Questions about this part? Contact us 4.8/5 1,329 store reviews
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60-day returnsEligible unused parts Free ground shippingUSA & Canada over $50
Browse all parts
Honda CB Master Cylinder Reservoir Diaphragm ~ Replaces 45520-300-000
$10.95 USD
Description

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 cylinders on the early SOHC CB750 and a broad classic-Honda lineup, plus REAR master cylinders on certain CB750F and CB900/CB1000/CB1100F models.

Key Features
• Master cylinder reservoir diaphragm
• Replaces OEM #45520-300-000
• Fits both FRONT and REAR master cylinders depending on model (see below)

Fitment / Compatibility

• FRONT master cylinder: Honda CB750K (1969‑78), CB750F (1975‑76) Supersport, CB750A (1976‑78) Hondamatic
• Also fits REAR master cylinder: CB750F (1975‑78) Supersport

• REAR master cylinder: Honda CB750F (1979‑82)

• REAR master cylinder: Honda CB900C (1980‑82) Custom, CB900F (1981‑82) Supersport, CB900F (2002‑07), CB1000C (1983) Custom, CB1100F (1983) Supersport

• FRONT master cylinder: Honda CB500K (1971‑73), CB500T (1975‑76), CB550F (1975‑77) Supersport, CB550K (1974‑78)

• FRONT master cylinder: Honda CB400A (1978), CB400TII (1978), CB450K (1970‑74)

• FRONT master cylinder: Honda CB350F (1972‑74) Supersport, CB400F (1975‑77) Supersport

• FRONT master cylinder: Honda CB350G (1973), CB360G (1974), CB360K (1974), CB360T (1975‑76)

Part Number: 08-0282

Read More
Read Less

Check the listed model and year, then read any fitment notes in the description.

Make Model Year
Honda CB750K Standard 1969
Honda CB750K 1970
Honda CB750K 1971
Honda CB750K 1972
Honda CB750K 1973
Honda CB750K 1974
Honda CB750K 1975
Honda CB750F Supersport 1975
Honda CB750K 1976
Honda CB750F 1976
Honda CB750A Hondamatic 1976
Honda CB750K 1977
Honda CB750A 1977
Honda CB750K 1978
Honda CB750A 1978
Honda CB750F Supersport 1979
Honda CB750F 1980
Honda CB750F 1981
Honda CB750F 1982
Honda CB900C Custom 1980
Honda CB900C 1981
Honda CB900F Supersport 1981
Honda CB900C 1982
Honda CB900F 1982
Honda CB1000C Custom 1983
Honda CB1100F Supersport 1983
Honda CB550K0 1974
Honda CB550K1 1975
Honda CB550K2 1976
Honda CB550K3 1977
Honda CB550K4 1978
Honda CB550F1 1975
Honda CB550F2 1976
Honda CB550F3 1977
Honda CB500K0 1971
Honda CB500K1 1972
Honda CB500K2 1973
Honda CB400F 1975
Honda CB400F 1976
Honda CB400F 1977
Honda CB350F0 1972
Honda CB350F0 1973
Honda CB350F1 1974
Honda CB900F2 919 2002
Honda CB900F3 919 2003
Honda CB900F4 919 2004
Honda CB900F5 919 2005
Honda CB900F6 919 2006
Honda CB900F7 919 2007
Honda CB500T Twin 1975
Honda CB500T Twin 1976
Honda CB400A 1978
Honda CB400TII Hawk 1978
Honda CB450K3 1970
Honda CB450K4 1971
Honda CB450K5 1972
Honda CB450K6 1973
Honda CB450K7 1974
Honda CB360T 1975
Honda CB360T 1976
Honda CB360G 1974
Honda CB360K0 1974
Honda CB350G 1973

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To the USA & Canada. In-stock orders usually ship from our own warehouse the same or next business day.

Estimated ground delivery after your order ships
DestinationDelivery time
USA4–7 business days
Canada2–6 business days

Ground shipping includes tracking, emailed when your order ships. Need it sooner? Express options are available at checkout.

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60-day returns on eligible parts

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Canada Post Economy: Available at checkout for select small items. Allow 1–3 weeks for delivery. No tracking or insurance is included.

Outside the USA & Canada: Delivery times vary by destination and shipping method. Buyers are responsible for applicable duties, taxes and import fees. We cannot mark orders as gifts.

Frequently Asked Questions

Which Honda OEM number does the master-cylinder diaphragm replace?

The diaphragm replaces Honda OEM number 45520-300-000.

What does the reservoir diaphragm do?

It separates brake fluid from outside air while allowing the reservoir volume to change as fluid level moves.

When should a master-cylinder diaphragm be replaced?

Replace it if it is torn, hardened, swollen or unable to seat correctly in the reservoir.

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