How to guide to replace front Brake Pads and Rotors on a W123
I thought I would make this pictorial for all the people that are clueless as to how to do this job, just as I was at first. I hope this helps everyone.
- 2 front rotors
- Set of front pads
- Disc brake wheel bearing grease
- Brake pad paste
- 10mm hex socket
- 5mm hex socket
- 19mm socket
- Torque wrench
- Channel locks
- DOT 4 brake fluid
- Jack up the car and place on good jack stands.
- Use needle nose pliers and pull the old sensors out. 9 times out of 10 they'll break, don't worry you have new ones.
- Use a nail or a punch to remove the 2 pins that hold in the bake pads and spring.
- You may have to use pliers to push the pads back and to pull them out.
- Use your 19mm 1/2" drive ratchet and socket to remove the 2 bolts that hold the caliper to the steering knuckle.
- Hang the caliper by a old wire coat hanger from the torsion bar. Never let it hang by the brake hose.
- Use a flat head and a hammer to remove the dust cap.
- Use a 5mm hex socket to loosen the bolt, don't remove this bolt, just loosen it.
- Unscrew the bolt from the spindle.
- Then the bearing will fall out, looks yummy. Then pull off the rotor.
- This should be what your left with.
- Use 2 or 3 lug nuts and bolt the rotor/hub back to your tire.
- Use your 10mm hex socket with 1/2" drive to remove all 5 bolts, there on there pretty tight.
- Remove the hub and rotor and hub from the tire. The hub should come apart from the rotor, just hit it with a hammer if it doesn't. Then bolt the hub to the new rotor and put it back on your tire and tighten the bolts to 84 Ft. pounds. Use blue locktight.
- Slide the rotor/hub back on the spindle.
- 16 slide the bearing back in after you have packed it with grease. Screw the big nut back on and tighten it then back off until you feel it break free(about 1/3 of a turn to the left). You don't want to much pressure on the bearing or it will not spin freely. Then snug down the 5mm bolt.
- Hit the dust cap back on and then put the caliper back on using lock tight on both bolts and torque them to 84FT pounds.
- Apply brake paste to the back of each pad.
- Push the piston in the calipers back and slide in the new pads.
- Snap in the new sensors your done.
I hope this will be of help.
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