First of all let me say that rotor retaining screws should be illegal. I spent more time trying to remove that screw that I did the caliper, caliper bracket and the hub/bearing.

Backstory: The left rear tire was losing air fairly quickly so I took it off and ran it over to my local NTB. They replaced a piece in the valve so hopefully that issue is resolved. While I had the wheel off I tried to rotate the rotor/hub. It did not want to turn well at all. Once I put the wheel back on I tried to spin it. It would only rotate about a half turn. The other side would rotate about 2 turns with similar force. I thought it was time for a new hub/bearing. I get a lot of noise around 55 mph and also thought that could also be the bearing.

I replaced the hub/bearing today. I had to (lightly) hammer out the inboard brake pad. I really thought nothing of it at the time. I got the new hub/bearing installed and started to put the brakes back together. I noticed that the brake hardware was very very dirty, to the point where they were gummed up. The tabs on the brake pads were also very dirty. I cleaned and wire-brushed everything. I had to spread out the hardware where the tabs ride in the caliper bracket. The outboard pads seemed to slide OK. I put a very small amount of Sil Glide to help keep them moving. It was extremely difficult to get the inboard pad in place. When I did it would not slide. I removed the hardware/clips and opened them up as much as I could. I also had to grind a small amount of material from each brake pad tab. I then put a little Sil Glide on those too. Both pads had plenty of material left, but the inboard pad was definitely thinner. In addition, it was extremely difficult to get the caliper back on. There is a rigid line attached to the back of the caliper that I assume is the emergency brake. This made reinstallation of the caliper tough. I would hate to see how that would go with new pads and rotors.

I think the issue with the wheel not rotating well is the inboard pad is not releasing and dragging on the rotor. If I understand correctly the caliper piston needs to be rotated back in for new pad installation. To me that would make the piston susceptible to dragging etc.

Any thoughts/ideas on if I'm on the right track here? I've searched a little bit for how to replace the caliper and haven't found much info. That semi-rigid line appears to be a pain to work around so any ideas or suggestions on that would be appreciated. One DIY just complete skipped that part. Otherwise I know how to replace a caliper.

 

your inboard pad is wearing because it's dragging, assuming everything is sitting fine. when in neutral, does the car coast and move freely, or does it seem to slow down on its own?
yes you do need to push the piston back in every time you change out pads. your hub likely did not need replacing if it is dragging. you mentioned them being gummed up...are you losing brake fluid?

 

The caliper was dry so I'm fairly sure I'm not losing any brake fluid.

I think the tabs and hardware are gummed up from brake dust residue and road filth etc.

 

If I recall correctly that piston "screws in", and best done with the special tool. I replaced the rear bearings, only to find out that when my tires are half worn out, the noise from the back of the car is unacceptable. This remains true for a couple sets of tires, not aggressive tires either!!!

 

my '09 and '11 were traditional style pistons.
op unless the trash is underneath the mounting tabs, it shouldn't effect your stopping. if you push your piston back in and your brakes are dragging, your calipers are done.

 

I'm going to verify that the parking brake cable is working correctly before I do much else. I then may look into either rebuilding or replacing the caliper. They're not cheap.

 

Hello - just replaced both my rear callipers on a 2008 R55. One side the inner was down to about 3mm whilst the others were all 8 - 10mm. These pads were new about 10,000 miles/ 3 years ago. Big clue was an excess of brake dust on that wheel compared to the other (and a marked difference in hub/disc temperatures after a short run trying not to use the brakes).
On the 3mm side the sticking was due, as you say, to the pads getting stuck on the stainless steel sliders. This was down to a combination of crud, rust on the carrier and the tabs - in general the whole caliper/carrier/ end of the handbrake cable was quite rusty and a couple of the spiralled wires gave way when it was unclipped.
The tabs sticking is common on a lot of vehicles and I've had it with some pads from new where there's been an over zealous application of black paint on them necessitating some filing. On the R55 this time the new inner ones all clipped in without too much trouble but I had taken care to clean off the entire carrier and fitted new sliders. There was a lot of rust under the stainless sliders - I should maybe check the free wheel rotation more often as these must have been going bad for a while.

Both sides I also replaced the callipers with a third party overhaul one - cost here was GBP £70 for the pair or GBP £30 for an overhaul kit - if you go down the third party route make sure it comes with the handbrake lever/spring assembly - some don't. Watch out for the handbrake and the brake pipe retaining clips - ECSTuning and others seem to carry them over your way but in the UK they're impossible to locate and in the EU rather expensive.

If you are having trouble getting past the steel bit on the handbrake cable then you can bend it a bit (I had to bend one of the new ones I bought just to get it to line up with the clamp). Beware that on older cables you may have a bit of corrosion at the top of the curved steel section where water tracks in and up the coiled 'spring' inside the plastic outer - that can trap the cable - it can also crumple if you try to bend the steel section or even just unclip the cable to replace the caliper (happened on my left side this time).

Replacing the cable is pretty much as described on Pelican Parts website with the difference that if you are careful you do not need to do anything with the heat shields - you can access the places where the cables clip to the fuel tank by easing the shields - unbolting the 10mm bolt head that holds the cable to the chassis may be the biggest problem if you have a lot of rust :-) . Releasing the cable from inside the car a 13mm deep socket does the job with maybe an assistant gently tugging from outside.