LiftMaster K75-12796 Motor Brake Pulley for APT Operators
The LiftMaster K75-12796 Motor Brake Pulley is a mechanical replacement component used in the brake area of select APT commercial trolley operators. The pulley works with the motor and brake assembly so the operator can stop and hold properly during normal commercial door operation.
This part is typically replaced when the pulley is worn, cracked, misaligned, or no longer supporting proper brake function. It is a precision fit component and should be matched to the APT operator breakdown rather than chosen by appearance alone.
What This Part Does
This replacement part is used to restore the correct mechanical or electrical function in the compatible LiftMaster commercial operator assembly. It should be selected by the manufacturer part number, the operator model, and the replacement parts diagram. Many LiftMaster commercial components look similar but are not interchangeable across operator families, voltage configurations, shaft sizes, rail assemblies, or production generations.
Compatible With
The following compatibility list is written from available LiftMaster-style parts references, distributor listings, and commercial operator parts breakdowns. Use it as a strong application guide, but match the exact operator tag and parts diagram before installation.
- LiftMaster APT commercial trolley operators
- Select LiftMaster Apartment Trolley Operator applications when the parts diagram lists K75-12796
- LiftMaster APT Logic 5.0 commercial trolley operator assemblies where this brake pulley is specified
- APT brake and motor assemblies that list 17-6014-1 or 310176014 as a related pulley reference
Also Known As / Related Part Numbers
These are manufacturer numbers, older number formats, catalog aliases, component references, or closely related parts customers may use when searching. Related numbers are not always interchangeable unless the operator parts diagram confirms the match.
- K75-12796
- 75-12796
- 17-6014-1
- 1760141
- 310176014
- Motor brake pulley
- Brake pulley for APT
- LiftMaster APT brake pulley
- Commercial trolley operator brake pulley
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Motor Brake Pulley |
| Part Number | K75-12796 |
| Related Part Numbers | 17-6014-1, 310176014 |
| Application | Brake and motor pulley replacement |
| Compatible Operator Type | Select LiftMaster APT commercial trolley operators |
| Common Operator Family | APT / Apartment Trolley Operator |
| Notes | Confirm brake assembly and shaft fit using the APT parts diagram. |
Technician Note
Commercial LiftMaster replacement parts should be matched to the operator model, serial range, voltage, handing, shaft size, rail style, and parts diagram. Do not order by appearance alone. Similar frames, pulleys, shafts, electrical boxes, bearings, and trolley parts may have different dimensions or mounting geometry even when the product names sound similar.
Before Ordering, Confirm
- Original part number or stamped/printed number on the existing component
- Exact LiftMaster operator model and series
- Voltage and phase when the product is electrical or part of an electrical box
- Right-hand / left-hand orientation when ordering frame parts
- Rail, trolley, shaft, chain, sprocket, or brake assembly style when ordering mechanical parts
- Parts diagram calls for this exact part number or a confirmed related number
- Door or gate moves freely and the operator is not being overloaded by a mechanical problem
Professional Advisory
Many of these parts are installed inside commercial door operators where moving components, stored spring force, and high-voltage wiring may be present. Disconnect power before service, follow the operator service manual, and use a qualified commercial door technician for internal drivetrain, brake, frame, or electrical box repairs. After replacement, test limits, controls, safety devices, brake action, and door balance before returning the operator to normal use.
Important Ordering Warnings
- Do not assume parts are interchangeable across T, GT, APT, MJ, MH, HMJ, GH, SD, GSD, LGO, or slide gate operator families.
- Electrical boxes and control parts must match voltage, phase, wiring type, and operator model.
- Handed frame parts must match left-hand or right-hand orientation.
- Mechanical drive parts should be checked with nearby shafts, bearings, sprockets, keys, chain, and brake hardware.
- If the operator failed because the door is binding, out of balance, or damaged, replacing the part alone may not solve the problem.
Questions & Answers
What does the K75-12796 motor brake pulley do?
It supports the brake and motor drive area in select LiftMaster APT commercial trolley operators, helping the operator brake and drive system function correctly.
Which operator family commonly uses this pulley?
The K75-12796 pulley is commonly associated with LiftMaster APT commercial trolley operator applications when shown in the parts diagram.
What are related numbers for this pulley?
Common related references include K75-12796, 75-12796, 17-6014-1, and 310176014.
Can a worn brake pulley affect door operation?
Yes. A worn or misaligned brake pulley can contribute to noise, poor braking, uneven movement, or accelerated wear in the brake and drive assembly.
Should the brake be inspected during replacement?
Yes. The brake components, pulley alignment, shaft fit, and related hardware should be inspected by a qualified commercial door technician.
