Brother BU-300CL Transfer Belt Unit — 50,000-page belt for the HL-4100 / DCP-9000 / MFC-9000 colour lasers
Genuine Brother~50,000 pagesUser-replaceableColour laser
The Brother BU-300CL is the genuine transfer belt unit for Brother's DCP-9055CDN, HL-4140CN, HL-4150CDN and MFC-9970CDW colour laser printers and their DCP-9270CDN, MFC-9460CDN and MFC-9465CDN siblings, rated by Brother at approximately 50,000 A4 pages. It is the part to order when the printer shows "Belt End Soon" or "Replace Parts Belt Unit".
The belt transfers all four toner colours from the drums to the paper. When it wears, colours drift out of register, smears and repeating marks appear, and the printer eventually stops asking for anything else. Fitting a new one is a user job that takes a few minutes, with no tools.
Before you order: BU-300CL fits the HL-4140CN/4150CDN, DCP-9055CDN/9270CDN and MFC-9460CDN/9465CDN/9970CDW generation. The older BU-100CL (HL-4040CN generation) and BU-200CL (HL-3040CN generation) belts are different parts and are not interchangeable.
What's in the Box
- 1 x Brother BU-300CL transfer belt unit
- Brother protective packaging; no drum, toner or waste toner box is included
What It Means in Practice
- Brother rates the belt at approx. 50,000 A4/Letter pages.
- The DR-320CL drum (approx. 25,000 pages at 1 page/job) and WT-300CL waste toner box (approx. 50,000 pages) are separate, so the belt and the waste box often fall due around the same time.
- After replacement, reset the belt counter: Menu > Machine Info > Reset Menu > Belt Unit > Yes.
- Do not touch the belt surface when handling it — fingerprints transfer to the print.
What Will Not Work
- It will not fit the HL-4040CN, HL-4050CDN or HL-3040CN generations — those use BU-100CL or BU-200CL.
- It is not a drum unit; faded or streaky single colours are usually a drum or toner issue, not the belt.
- It does not clear a waste toner warning — that needs the WT-300CL.
- Resetting the counter on the old belt does not fix print defects.
Key Features
Genuine Brother belt
Made by Brother for this printer family and its genuine toner, drum and waste toner box.
Approx. 50,000 pages
Brother's rated life for A4/Letter paper.
Tool-free swap
Remove the drum unit by its green handle, release the lock lever, lift the belt out and fit the new one.
Front-panel reset
Belt counter reset from the Reset Menu under Machine Info.
Technical Specifications
| Identification |
| Part Number |
BU-300CL |
| MPN |
BU300CL |
| Brand |
Brother |
| Product Type |
Transfer belt unit |
| Performance |
| Yield |
Approx. 50,000 A4/Letter pages |
| Compatibility |
| HL series |
HL-4140CN, HL-4150CDN |
| DCP series |
DCP-9055CDN, DCP-9270CDN |
| MFC series |
MFC-9460CDN, MFC-9465CDN, MFC-9970CDW |
| Related parts |
Drum DR-320CL · Waste toner box WT-300CL |
| Installation |
| Replaced by |
User |
| Tools |
None required |
| Counter |
Menu > Machine Info > Reset Menu > Belt Unit |
| Warranty |
| Warranty |
1-Year Warranty (Singular) |
| Manufacturer Term |
Brother does not publish a separate EU warranty term for belt units; manufacturer defect claims are handled through Singular. |
Frequently Asked Questions
My printer says "Belt End Soon" — do I have to stop printing?
No. It is an early warning; you can keep printing until "Replace Parts Belt Unit" appears. Ordering now avoids downtime.
Can I use a BU-200CL from an older printer?
No. BU-200CL is for the HL-3040CN generation and does not fit these models.
Do I need to replace the drum at the same time?
No. The drum has its own counter and life; replace it only when the printer asks.
Singular Expert Insight · Buyer's Guide
BU-300CL belts usually come up after several years of service, when the printer is otherwise still healthy — a new belt is far cheaper than replacing a working colour laser. Check whether the waste toner box warning is also close, since both parts are rated at around 50,000 pages. See our
printer accessories and service parts for other parts for this family.
✓ Buy it if your HL-4140CN, HL-4150CDN, DCP-9055CDN/9270CDN or MFC-9460CDN/9465CDN/9970CDW asks for a new belt.
✕ Skip it if your printer is an HL-4040CN/4050CDN or HL-3040CN family model — it uses a different belt.
→ Also consider Brother WT-300CL waste toner box and DR-320CL drum unit for the same printers.
Not sure which belt your printer takes? Send us the model from the printer label and we will check it before you order.