Rep Power: 0

Last year I replaced the cars pads (all four wheels) fitting EBC Ultimates..
Well reviewed as slightly more aggressive than OEM pads. Worked well Road trips though the mountains Zero issues. a month later after washing the car the discs got a bit of surface rust.
Then the rear brakes began to audibly (drivers seat) grind The grinding never went away. Removed discs sanded them shiny and the pad surfaces. Worked Great until it rained then Grinding started .. again. Got EBC to Warranty their pads and thinking the pads weren't aggressive enough to wipe of car wash disc rust. Supplied EBC Green pads which were more aggressive. And worked well... Only for as long as the EBC red break- in coating lasted.
Grinding is back.
The other day I removed the OEM Discs and Fitted Centric replacements. Worked Fine.. Until it rained over night. Now the grinding is back
ANY body have any clues as to why this is happening ?? (Car has 50,000 miles) .there is no disc runout .
Calipers are clean and seemingly working , as in heavy test braking does heat up the discs.
Yet the low speed brake grinding continues., where logic suggests that All the rain rust was scoured off by the heavy braking attempts. .
But it hasn't been scoured off ..
Only plausible Guess "may' be that the caliper or the Brake balance valve isn't supplying the correct amount of rear brake bias.. Do Hondas even have one?
Help ??

 
Rep Power: 221

Rear calipers need to be serviced every 20k-30k kms and when replacing pads/rotors. Did you do any of that?
Warped rotors? Seen warped rotors fresh out of the box
Ebrake cable sticking?
And finally calipers may be starting to seize up

 
Rep Power: 366

if you have ABS, it does the proportioning.
EBC and other pads usually grind more, my Hawks did

disassemble and check, like mentioned above

 
Rep Power: 0

Yesss the possibility of a messed caliper did occur. Rebuild kits are currently 'en route' .. (expected next tuesday)
That said, the calipers still have their shiny cad coating and 'appear' in pristine condition.
But looks can be deceiving. Maybe they are seized.. or close to it.
As small defense.. In the past, on 'other' cars Calipers that needed a refresh were visibly aged/rusted... these are not.
One disc (the suspect right rear 'grinder' ) did have a V Slight warp. So I replaced both rear rotors 2 days ago
Which worked well ... for One day... then it rained overnight and the rust/grinding returned... as before.
Darned calipers (pads?) don't seem to be squeezing enough to wipe off even overnight rain caused rust.... curious.
Same pads on Front discs have No problems whatsoever wiping the same rain rustings
Just this afternoon removed rear discs and surface sanded off the rust, it came off fairly easily, by hand with a piece of 80 grit
Rotors are currently rust and consequently noise free .
However ...IF ..it rains overnight I'm expecting the grinding will be back. just as it did.. 3 times previously .

My only hope is that a caliper rebuild makes a difference.

 
Rep Power: 366

most likely just need slider pin lubrication, it hurts to insert without lubrication

 
Rep Power: 0

No... Good thought though.. thanks... However I've tried that , repeatedly.
Completely cleaned and re greased the pins with EBC slider grease,.. the third time in 6 months.
Sliders are Free sliding.
Been wrenching on my cars for 40 + years.. Not many things stumpme these days... but these pesky brakes have.
Only remaining hope left is a caliper disassembly / rebuild .
Rubber brake hoses can turn into one way valves when badly deteriorated/aged. But typically they retain pressure (brakes stay on/drag)
Wondering how involved it might be to measure the Fluid pressure reaching the rear calipers ?
Maybe the reverse Syringe method.. when the Caliper is off might give a clue.

 
Rep Power: 221

The hoses are cheap enough I would just replace them.
Another thought, is there rust build up on the hub? That may be causing the rotor to not spin true

 
Rep Power: 0

Received my Rock auto (centric) Rear caliper kits 3.30 cdn $ each , versus local Dealers 45Cdn $ each . Happily I had no need to fit them.
Turns out that My sanding (80 grit) the Previously Newly fitted rotors 'Fixed' the issue... completely.
I can only assume that these Centric rotors were mislabeled (6.48 Cdn$ each on Rock auto closeout.. So no real cause to complain ).
Seems these were Coated types (no labellings whatsoever) as my usual wipe down with laquer thinners and then CRC Brake cleaner apparently hadn't fully removed the coatings.. if at all.
Plus the EBC pads had mostly worn off their Red break in layer.
Sooo... the careful sanding/scourings seems to have cleared the source of the grinding noises.
There have been some Monsoon like rains since then ...and there are No longer any grinding issues.