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Determining Alcon caliper seal diameters

Determining Alcon caliper seal diameters

We consistently get asked to help identify which size caliper seals to order.  This guide should help.If you don't have a part number visible on your caliper - you will need to measure the outside diameter of all pistons on one side of the caliper

Look at your Caliper Part number.    Positions with letters designate letters in the part number.  Positions with numbers have numbers.  Parenthesis are optional.  So B(B) could be one letter or two.


Alcon Caliper Part number designator.  B(B) is the piston diameter designation.  See the chart below

CAR 1111 B(B)  22 CC D E F


C - Caliper

A - (A)luminum or (I)ron

R - (R)adial or (L) lug mount

1111 - Caliper Series

B(B) - Piston Sizes (See chart below)

22 - Serial Number

CC - Piston Spec  (A)luminum, (T)itanium, (V)entilated titanium, (S)tainless, (D) Clip in insert, (X) clip in insert ventilated, (E) Low friction coating, (A) Low Friction coating type 2.

D - Abutment Matrial (A)luminum, (S)teel, (T)itanium, or (Z) no abutments

E - Side - (L)eft or (R)ight

F - Location (L)eading or (T)trailing




CAR9850H - would be an Aluminum Radial Mount Caliper Series 9850 with 38.1mm and 41.3mm pistons

CIR5059D - would be an iron caliper 5059 series with 34.9mm / 34.9mm pistons



Alcon Piston Size Chart (8th Digit)



A: 28.6/28.6

B: 31.8/31.8

C: 31.8/34.9

B: 25.4(x6)
D: 34.9/34.9

E: 34.9/38.1

F: 34.9/41.3

G: 38.1/38.1

H: 38.1/41.3

J: 38.1/44.5

L: 41.3/44.5

 K: 41.3/41.3

M: 41.3/46.8

N: 41.3/47.6

P : 44.5/44.5

R : 44.5/46.8

S: 44.5/47.6

T : 22/25. 4/30.2

U : 36/38

V : 22.2/25.4



W: 33.3/38.1/44.5


Y : 27/31.8/38.1

Z : 30.2/34.9/41.3



AA: 25.4(x12)

AC: 25.4(x4)/22.2(x2)

AD: 30.2(x6)
AE: 28.6(x2)/34.9(x2)

AF: 26/31.8/36

AG: 28.6/33.3/36

AH: 40.0(x4)

AJ: 30.2/34.9

AK: 27.0/30.2

AL: 28.6(x8)
AM: 31.8/34.9/41.3
AN: 28.6/31.8/41.3
AP: 28.6/31.8
AR: 28.6/34.9
AS: 30.2(x8)
AT: 27/28.6
AU: 33.3/38.1
AV: 48.0/48.0
AW: 30.2/33.3








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