My motorcycle Choose your Honda CB model

Search parts

Searching all Honda CB parts

Example: brake pads or oil filter.

4.8/5 from 1329 CB riders Read Reviews
Honda CB750 CB900 CB650 master cylinder diaphragm 45520-422-026
Parts fiche reference for SKU 08-0285

Honda CB Front Master Cylinder Reservoir Diaphragm ~ Replaces 45520-422-026

08-0285
$11.50 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

$11.50 USD

Replace the diaphragm on your early DOHC CB's front master cylinder reservoir with this Front Master Cylinder Reservoir Diaphragm, replacing OEM #45520-422-026 / #45520-422-006 / #45520-422-016. Fits the 1979-80 CB750 family, 1980-81 CB900C, 1979-80 CB650/CB650C, and 1979-80 CB400T/TII.

Key Features
• Front master cylinder reservoir diaphragm
• Replaces OEM #45520-422-026 / #45520-422-006 / #45520-422-016

Fitment / Compatibility

• Honda CB750K (1979‑80)
• CB750F (1979‑80) Supersport
• CB750C (1980) Custom
• CB750L (1979) Limited


• Honda CB900C (1980‑81) Custom


• Honda CB650 (1979‑80)
• CB650C (1980) Custom


• Honda CB400T (1980)
• CB400TII (1979)

Part Number: 08-0285

Read More
Read Less

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

Honda motorcycle models and years listed for this part
Make Model Year
Honda CB750K Standard 1979
Honda CB750F Supersport 1979
Honda CB750L Limited 1979
Honda CB750K 1980
Honda CB750F 1980
Honda CB750C Custom 1980
Honda CB900C Custom 1980
Honda CB900C 1981
Honda CB650 1979
Honda CB650 1980
Honda CB650C Custom 1980
Honda CB400TIIZ Hawk 1979
Honda CB400TA Hawk 1980

Free ground shipping over $50

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.

60-day returns on eligible parts

No restocking fees. Eligible parts must be unused, uninstalled, unaltered and complete. The 60-day window starts when your order is delivered.

Electrical parts are excluded from standard returns. Check return eligibility.

Start your return below. Wait for our instructions before mailing a part back.

Start a return

Other shipping options

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 early DOHC Honda models fit front master cylinder diaphragm 08-0285?

It fits the front brake reservoir on 1979-80 CB750K and CB750F, 1980 CB750C, 1979 CB750L, 1980-81 CB900C, 1979-80 CB650, 1980 CB650C, 1980 CB400T and 1979 CB400TII models.

Which Honda OEM diaphragm numbers does 08-0285 replace?

Front master cylinder diaphragm 08-0285 replaces Honda OEM 45520-422-026, 45520-422-006 and 45520-422-016. Use those OEM references and the exact model year to distinguish it from later MA5-style reservoir diaphragms.

Is 08-0285 a complete master cylinder rebuild kit?

No. It is the rubber diaphragm beneath the front master cylinder reservoir cover; the cover and hydraulic piston rebuild parts are separate.

See Why Customers Love Us

Your cart

×