Tom F&L GoR
Enthusiast
no, No, NO.... you can\'t do this to your rear brakes!!!!
I just got back a set of cores to rebuild into 40mm rear calipers. They are unusable because at one point someone tightened or loosened the bolt holding the parking brake lever and didn't hold onto the lever itself. Everyone needs to know that there is no "stop" to support the internal pieces when you do this. It is particularly easy to do on the passenger side, since to unscrew the bolt (counterclockwise) you are working against only the parking brake cam plates. And guess what - they break!
Yes, it's bad for me, but it's also dangerous for you. The hardened steel shatters and while the picture shows the major piece, there are a few small slivers missing.
Normally when you pull on the parking brake the cable pulls on the external lever arm. Attached to the lever arm is a mating plate like this broken one, also with three teardrop shaped holes, but the teardrops are pointed in the opposite direction. Ball bearings are in the deep end of the teardrop shaped holes, keeping the two plates slightly separated. When the parking lever arm rotates the plate, the balls roll from the deep end to the shallower pointy end of their hole, spreading the two plates apart. The plate rotated by the brake lever arm can't move because it's up against the inside of the caliper body (and it rides on the needle bearing) the other plate must move and pushes the piston to engage the parking brake mechanically (not hydraulically.)
When you loosen or tighten the bolt holding the parking brake lever on, you are placing more force on these plates than they can handle.
The other, less dramatic failure is if the snap ring holding the plates in their cavity inside the caliper pulls through (the one on the left). Although it's also an irreplaceable part, it is more safe because it doesn't leave broken bits loose inside the caliper.
You do not need to remove the lever arm anyway. With the parking brake disengaged, you can take pliers, grab the ball at the end of the parking brake cable and there is enough slack to guide the cable out of the slot in the end of the lever arm. Same for replacing it - pull on the cable and there will be enough slack to re-engage the cable in the lever arm.
If the calipers are off the car, put the tip of the lever arm in a vise and unscrew the bolt. Somehow, you must hold on to the arm, do not rely on the internal parts of the caliper.
Please, please don't remove the brake arms. If you have any questions, find me and ask me.
I just got back a set of cores to rebuild into 40mm rear calipers. They are unusable because at one point someone tightened or loosened the bolt holding the parking brake lever and didn't hold onto the lever itself. Everyone needs to know that there is no "stop" to support the internal pieces when you do this. It is particularly easy to do on the passenger side, since to unscrew the bolt (counterclockwise) you are working against only the parking brake cam plates. And guess what - they break!
You must be registered for see images
Yes, it's bad for me, but it's also dangerous for you. The hardened steel shatters and while the picture shows the major piece, there are a few small slivers missing.
Normally when you pull on the parking brake the cable pulls on the external lever arm. Attached to the lever arm is a mating plate like this broken one, also with three teardrop shaped holes, but the teardrops are pointed in the opposite direction. Ball bearings are in the deep end of the teardrop shaped holes, keeping the two plates slightly separated. When the parking lever arm rotates the plate, the balls roll from the deep end to the shallower pointy end of their hole, spreading the two plates apart. The plate rotated by the brake lever arm can't move because it's up against the inside of the caliper body (and it rides on the needle bearing) the other plate must move and pushes the piston to engage the parking brake mechanically (not hydraulically.)
You must be registered for see images
When you loosen or tighten the bolt holding the parking brake lever on, you are placing more force on these plates than they can handle.
The other, less dramatic failure is if the snap ring holding the plates in their cavity inside the caliper pulls through (the one on the left). Although it's also an irreplaceable part, it is more safe because it doesn't leave broken bits loose inside the caliper.
You must be registered for see images
You do not need to remove the lever arm anyway. With the parking brake disengaged, you can take pliers, grab the ball at the end of the parking brake cable and there is enough slack to guide the cable out of the slot in the end of the lever arm. Same for replacing it - pull on the cable and there will be enough slack to re-engage the cable in the lever arm.
If the calipers are off the car, put the tip of the lever arm in a vise and unscrew the bolt. Somehow, you must hold on to the arm, do not rely on the internal parts of the caliper.
Please, please don't remove the brake arms. If you have any questions, find me and ask me.
