4 piston caliper ?

[poppa]

Why are there springs behind the pistons ? Are they really needed ? I still have some drag on one caliper and when I took them apart to paint them ,I remember one spring was noticably stronger/heavier gauge than stock. I would bet that the caliper that is draggging has this spring in it. I will probably pull it and check. Got these rebuilt/exchanged on line.

[hemi68charger]

I rebuilt mine not too long ago on my '69 Charger 500.. Seem to be working fine with the spring..

[poppa]

But why is the spring there?

[John_Kunkel]

The springs keep the pistons from retracting too far, if they retract too far the volume of fluid needed to apply the brakes will cause a low pedal.

[poppa]

Thank you .