There isn’t a universal size for caliper bolts. In most passenger cars and light trucks, you’ll use a metric socket in the 12–14 mm range, with 14 mm being the most common. Always check your vehicle’s service manual or inspect the bolt head to confirm the exact size before you wrench.
Caliper bolts secure the brake caliper to the mounting bracket and can come in different head designs depending on the make and model. Access to the bolt head can also affect which tool you use, such as a standard socket, a deep socket, an Allen/Hex key, or a Torx bit. The guidance below outlines typical sizes and how to determine the correct tool for your specific vehicle.
Common sizes you’ll encounter
The following sizes cover the majority of passenger cars and light trucks. Always confirm on your specific model.
- 12 mm socket — frequently found on certain Asian and domestic models.
- 13 mm socket — less common, but seen on some vehicles.
- 14 mm socket — the most common size for caliper mounting bolts in many makes and models.
- 15 mm socket — used on some European vehicles and select models.
- 17 mm or larger — rare, but may appear on older trucks or heavy-duty applications.
Note that this list focuses on external hex head bolts that accept a standard socket. Some vehicles may use different head configurations that require other tools.
Vehicle-specific considerations
If none of these sizes fit, consult the service manual for your exact model or bring the bolt to a parts counter to identify the correct size. Using the wrong size can strip the bolt or damage the caliper, and improper reassembly can compromise braking performance.
Other head configurations you might encounter
Some caliper bolts do not use a standard external socket head. Being aware of alternate head designs can save time and prevent damage.
- Internal hex (Allen) heads — commonly 6 mm or 7 mm, requiring an Allen key or hex bit.
- Torx heads — sizes vary by model; if you see a star-shaped recess, match it with the correct Torx bit.
- Other specialized fasteners — a small number of vehicles use unique head designs; in those cases, refer to the official service manual for the exact tool specification.
When working on brakes, always use the proper tool, apply steady torque, and avoid forcing a bolt that doesn’t fit. After reassembly, torque to the manufacturer’s specification and verify brake function in a controlled environment.
Summary
In short, there is no one-size-fits-all answer for caliper bolts. Most commonly you will need a 14 mm socket, but models vary and sizes from 12 mm to 15 mm (and occasionally other head types such as Allen or Torx) can appear. Always verify with the vehicle’s service manual or by inspecting the bolt head, and use the correct torque when reinstalling to ensure safe braking performance.
What size wrench for caliper bolts?
A decent 3/8-drive ratchet and allen socket is all you need. The torque setting on the caliper pins is around 30 ft/lbs. They are quite easy to remove with a ratchet.
How to get a brake caliper bolt out?
Itself. And go ahead and break it. Free. Now I got them both broken free you just go ahead and remove the bolts entirely. So I'll just ratcheting all all the way out. Again.
What size socket to remove brake caliper bolts?
There you go we're just going to press down crack that open one and the second one on. Here. Takes a little bit of work. But right after gets pretty easy.
What tool is used to remove caliper bolts?
Brake Caliper Pin/Bolt Remover Set is designed to remove frozen caliper pins by allowing a striking force to be applied to the pin, not feasible without these tools, making removal quick and easy. Works equally as well on bolts in non-threaded holes. Will not damage pin or bolt like a chisel or punch could.