How to-Tell How Many Pistons are in a Brake Caliper?

How to-Tell How Many Pistons My Brake Calipers Have?

Quite frequently our online lookup will ask the user how many pistons their front/rear calipers have. Don’t worry! You probably don’t even have to take off your wheel to find the answer to this question. With modern vehicles’ open wheel designs, it is usually possible to visually confirm how many pistons your calipers have. As a general rule, on 1 and 2 piston sliding calipers, you can frequently see “arches” on the face of a caliper. If you count the arches, then you can usually tell how many pistons are in the caliper. 4 and 6 piston calipers are a little more tricky but you can still usually see the outline of the 2 or 3 outboard pistons.

Single (1) Piston calipers are always sliding calipers that move slightly as the brake pads wear. Most have a bracket but on some the bracket is built into the knuckle of the vehicle. Some rear single piston calipers also have a mechanism on the back for the parking brake.


Dual (2) Piston Calipers are usually sliding calipers with brackets, but some 2 piston calipers are fixed position with opposing pistons – one on the inboard and one on the outboard side.



4 Piston Calipers are almost always going to have 2 inboard and 2 outboard opposing pistons. 4 piston calipers are almost always a fixed position design so you won’t see the bracket surrounding the caliper as in the 2-piston caliper above. That being said, instead of seeing two ‘arches’, you will instead see 2 general outlines of the 2 outboard pistons.


6 Piston Calipers are almost always 3 inboard and 3 outboard opposing pistons, and similar to the 4 piston design, they are almost always fixed position calipers without a bracket. On 6 Piston Calipers, you will usually be able to see the outlines of the 3 pistons on the outboard side of the caliper.

If you have any questions you can always reach out to our tech team ( and they should be able to assist figuring this out.

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