How to figure out a piston diameter without removing it from the caliper.
This method is for your convenience & a general guideline only, due to the variation of the original pistons, it's your assurance to "pop" the piston out of the caliper to actually measure it for accuracy.
Applicable to aftermarket calipersand those not listed in our standard OE caliper offer matrixonly.
If you also purchase pistons, the piston must be removed from the caliper to measure the height.
For traditional internal boot fitment type piston.
1. Measure the flange diameter eg. 34.5mm 2. Add 3.5mm, the piston diameter=38mm
For new style external boot fitment type piston.
1. Measure the flange diameter eg. 30.5mm 2. Add 7.5mm, the piston diameter=38mm