I am copying (and elaborating) some text that accompanied refurbed rear calipers I got this week. In all my years I have not found a formal description for this task. I remember reading somewhere before that you cannot use the handbrake until the caliper is fitted, bled and that any gaps to the pads have been overcome - but this explains why that is important as if you get it out of sequence then the internal handbrake mechanism may need reset.
Warning -
Do NOT operate handbrake lever before fitting to the vehicle. The unit has been preset at the factory. If you operated the handbrake lever, then reset it as follows. The handbrake cable should be fitted last.
To reset the handbrake mechanism before fitting the caliper, the piston should be rotated IN (clockwise). When the piston is fully IN - then the piston should be turned OUT by 0.5 to 1 turn. The handbrake mechanism is now reset.
Adjustment & Fitting -
Adjust the pad gap on the caliper by rotating the piston OUT until there is no more than 1mm clearance between brake pads and disc.
Rotation of the piston should be done with the correct 'piston winder' tool. Fresh calipers can be rotated with care using long nosed pliers.
If the piston is rotated OUT too far for pad fitment then it needs to be rotated IN by at least half a turn to ensure the internal mechanism has reset.
Fit the caliper and brake pads and ignore the handbrake cable for now.
Bleed the caliper.
Finally fit the handbrake cable and adjust to remove any slack. Ensure the gap between lever and end-stop does not exceed 1mm.
Top Tip -
I found that I had to relax the handbrake cable tension by a considerable amount in order to fit the cable into the new caliper. Then I reapplied the tension while checking the clearance was good. This job is made VERY easy if you have a 10mm deep socket on 1/4 inch 'wobble bar' extensions so you can get to the tensioner in the tunnel without having to fight with the exhaust and heat shield.
Warning -
Do NOT operate handbrake lever before fitting to the vehicle. The unit has been preset at the factory. If you operated the handbrake lever, then reset it as follows. The handbrake cable should be fitted last.
To reset the handbrake mechanism before fitting the caliper, the piston should be rotated IN (clockwise). When the piston is fully IN - then the piston should be turned OUT by 0.5 to 1 turn. The handbrake mechanism is now reset.
Adjustment & Fitting -
Adjust the pad gap on the caliper by rotating the piston OUT until there is no more than 1mm clearance between brake pads and disc.
Rotation of the piston should be done with the correct 'piston winder' tool. Fresh calipers can be rotated with care using long nosed pliers.
If the piston is rotated OUT too far for pad fitment then it needs to be rotated IN by at least half a turn to ensure the internal mechanism has reset.
Fit the caliper and brake pads and ignore the handbrake cable for now.
Bleed the caliper.
Finally fit the handbrake cable and adjust to remove any slack. Ensure the gap between lever and end-stop does not exceed 1mm.
Top Tip -
I found that I had to relax the handbrake cable tension by a considerable amount in order to fit the cable into the new caliper. Then I reapplied the tension while checking the clearance was good. This job is made VERY easy if you have a 10mm deep socket on 1/4 inch 'wobble bar' extensions so you can get to the tensioner in the tunnel without having to fight with the exhaust and heat shield.
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