I replaced my rear brake discs this weekend and had a bit of trouble with the EPB. I could not get it into a "mounting" or service mode (3 pumps of the brake pedal and hold the EPB lever down). I also could not get the adjustment knurl to turn at all. I managed to get the discs off fine and found out the adjustment knurl was all the way compressed already.

I put the new discs on as is and low and behold, the EPB shoes are dragging. Is there another adjustment I'm missing? Why would the adjustment already be fully closed and why are the shoes still dragging? Makes me think something else isn't adjusted right.

 

I'm not sure I've ever been able to use the brake pedal, EPB lever method to get into service mode. I just do it with the IID tool. There may be some secret that I'm not aware of, but I'm pretty certain I tried it the Bodsy's Brake Bible way and had no success.

As far as the shoes dragging, there are a couple of things. When you install the shoes and put the rotors back on, before adjusting the star wheel, whack the drum with a soft blow mallet a bunch of times pretty hard. This should allow the pads to settle down a bit and get into more of a "circle". Then, adjust the star wheel 7 clicks (or however many it's supposed to be) and do it again. Finally, and probably the most important step, make sure you follow the proper bedding in procedure. This should also help to center the shoes once again as well as forming the shoes to the inside of the rotors.

 

Darn, I didn't realize the IID tool could do it. I'll have to check when I get home.

I'm just stumped because the adjustment knurl was already fully released before I touched anything. EPB was working fine, but likely dragging slightly (heard a slight metallic grinding since I bought it). Makes me think something else somewhere is out of adjustment or not on right.

I did do a couple of bedding runs as described with the EPB, but with no change after 4 or 5 stops I didn't want to damage anything.

I think I'm going to have to just take it to my mechanic and have them figure it out.

 

Not sure what you mean by the "adjustment knurl was already fully released". Does that mean that the spreader with the star wheel was all the way out (pushing the pads apart) or all the way in (pulling them together)? I think you mean pulling them together?

Do you have the procedure for setting the star wheel? I believe you're supposed to make it fully compressed, put the rotor on, and then spread it apart until you have tension on the wheel. Then, keep rotating the star wheel until it takes a certain amount of force to turn the entire wheel (measured with a torque wrench). Once you're in the correct range, I think you turn the star wheel another 7 times.

I can't remember at what point you release it from the service position... before or after the adjustment, but it's in Bodsy's Brake Bible.

 

Yeah so essentially you are supposed to adjust the star wheel so it is all the way together, pulling the pads in and away from the drum so you can get the rotor off and the new one on. I've consulted the "bible" as well as the official manual.

When I went to do that, I couldn't turn it any more to adjust the pads together, they were already all the way together.

So the pads are adjusted to be all the way together (i.e. they shouldn't be contacting the drum at all) and are still contacting the drum.

Perhaps the whole parking brake "package" is off center or not positioned correctly inside the drum?

 

Certainly possible, which is why the soft blow mallet is critical. Make sure the shoes are hinged properly on the areas they are supposed to be, and center them as best you can, then, as you adjust the star wheel out so that they are putting pressure on the inside of the rotor, hit the rotor with the soft blow hammer a bunch of times. That should help to center them.

 

Did you lossen hex nut that holds the shoes to the face place while you were adjustwer them? Maybe they are off center and one of the shoes is dragging even though the overall diameter is less than the drum.

 

I did try that. Didn't seem to have any effect. Also did the bedding procedure, no change. The mechanic can't figure it out either, but seems convinced that the rotors are to blame (they are Raybestos). He's going to try LR rotors and see if that resolves the issue. I'm personally skeptical of that theory.


I wonder if there is an adjustment in the EPB module itself, where if I adjusted the parking brake shoes using the adjustment wheel tight (too tight, so locked basically), the EPB would back off since it measures based on force applied.

Just wondering if maybe having the adjustment wheel all the way released caused the EPB module to compensate and now with new rotors it is too much, causing drag.

 

Well, if the brake shoes and rotors are worn too much, I believe the EPB module itself will adjust to accommodate for the wear and eventually jam the adjustment nut (which is what happened to me on the back roads of Vermont). I used the IID tool to run the "unjam" procedure in order to back it off. You could give that a try and see if it does anything...