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Rust Belt Owners and Rear Brakes

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by 72fordgts, Apr 16, 2015.

  1. 72fordgts

    72fordgts Member

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    Does anyone who lives in the rust belt and faces salty winters have issues with the rear brake pads sticking? Our car sees long cold winters on rural roads with lots of sand and salt. At least twice a year our car has required the rear brakes to be disassembled, cleaned or the pads ears will seize in the clips. This has happened a couple of times in our ownership and it of course then causes one of the pads to wear prematurely. I have never had an issue with the pins, they work fine. The front brakes have always been decent too, but it's probably because they see more use.

    Has anyone else seen this issue? Is there any solution that works to keep the pads from constantly sticking? This car's rear brakes are the worst of any car I have ever owned in terms of the pads seizing up.
     
    #1 72fordgts, Apr 16, 2015
  2. css28

    css28 Senior Member

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    We bought our car in March 2012 so I'm expecting a similar experience soon.

    The best I can recommend is trying different greases to see if one works better than another in preventing this.

    There's really not much else I can imagine given the fundamental arrrangement of things.
     
    #2 css28, Apr 16, 2015
  3. bisco

    bisco cookie crumbler

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    yes there has been a lot of this documented and several excellent procedures with pictures. see member 'mendel leisk', he has an excellent write up.
     
    #3 bisco, Apr 16, 2015
  4. 72fordgts

    72fordgts Member

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    Thanks for the replies. Any help on what to search for that thread?

    As for the grease, I have used synthetic silicon brake grease, but it also tends to collect dirt which also resists the pad movement.
     
    #4 72fordgts, Apr 17, 2015
  5. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    Make sure when reassembling rear brakes that the inside pad backing plate pin is INBETWEEN the spokes on the caliper piston face. I keep harping on this cus I got caught: if the pin's ON the spoke it'll cause a lot of drag and uneven wear.

    Also worthwhile to have a close look at all your suspension components, any and all steel fasteners. We're definitely NOT in the snow belt. We get a token amount, but not much.

    Rustproofing the suspension | PriusChat

    Here's my post on rear brake pads. It's a learning experience for me, but even I could see something was wrong, one rotor in particular was 50% rusty, unused. I just purchased new pads and shim kit, steel wool cleaned the rotors, assembled everything carefully with the pin to piston alignment correct, and something like 8 months later they're looking fine. The rotors look back to normal, shiney, front and back.

    Rear Brake Concerns | PriusChat
     
    #5 Mendel Leisk, Apr 17, 2015
    Last edited: Apr 17, 2015
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  6. 72fordgts

    72fordgts Member

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    Thanks very much for sharing those links, great info!! When it comes to the rust proofing, I have had our car Krown rust proofed since 2010. It helps, but you car looks much cleaner than ours does after 5 long salty winters. Not that our car has much more rust, but the undercarriage is much dirty due to the build up caused by the rustproofing. In any case, out car is in a heated garage and seems to be holding up very well in terms of rust compared to our previous vehicles.

    Our first set of rear brake pads lasted about 90K km's, due to one pad seizing which wore the other moving pad excessively. This second set is probably not even going to make it that far (we have about 55K on them now), but it is an aftermarket pad (CARQUEST Blue). I won't be using them again. The front pads lasted about 120K kms but wore pretty evenly. Again, great information.
     
    #6 72fordgts, Apr 18, 2015
  7. The Critic

    The Critic Resident Critic

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    #7 The Critic, Apr 20, 2015
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  8. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    The first picture in that link looks a lot like what I was seeing:

    photo 3.JPG

    Albeit a lot further gone.

    I'm pretty much convince it's that pin on the back of the inner pad that's the culprit. It's near the outer edge (where my thumb is), if/when the pin rides up on a piston spoke, all your braking pressure is skewed to that side.

    Carefully install of regular new pad set, with the pin carefully aligned, and initially pressuring up the brakes while watching them (multiple pumps of the brake pedal), getting them seated and that pin locked, did the trick for me.

    I suspect what might happening when it misaligns is:

    the brake is assembled, with the pin properly aligned, but before pressurizing the brake via the brake pedal, the parking brake is applied. The latter will attempt to rotate the piston, and if the brakes aren't solidly seated, the piston spoke locked on that pin, it will manage to turn, and the spoke crest will ride up on the pin.

    Bottom line, for me: Toyota's come up with a finicky design, and without careful, specific actions during installation, it fails.
     
    #8 Mendel Leisk, Apr 20, 2015
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  9. 72fordgts

    72fordgts Member

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    Thanks again for the helpful information. I think I probably wasn't careful enough with the pin alignment (the Toyota Service manual isn't very clear IMO). The other thing I noticed on the updated part is that the clips seem to be coated. THIS is the other big issue that I have had. Those clips always corrode and the brake pad ears seize inside them. Then if you do lubricate them, they get full of sand and dirt which restricts movement enough at some points that they basically seize.

    I wonder if the aftermarket made any of these updates? I may be stuck buying our next set of pads from Toyota, which means super inflated prices. But if they last I suppose it's worth it. Looking at some of the pads listed on Rock Auto, many of the aftermarket pads don't even have the pins.
     
    #9 72fordgts, Apr 20, 2015
  10. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    FYI, my purchase through a dealership, Westminster Toyota in New West (who always seem to undercut Open Road Toyota by about 10%):

    Pad Set 04466-76012: $99.69
    Shim Kit 04946-47070: $16.77

    I'm not sure, but don't think it was the revised, recall set.
     
    #10 Mendel Leisk, Apr 21, 2015
  11. Jim T

    Jim T Junior Member

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    At about 4 years and 40k miles I noticed a clunk coming from the rear wheels when first backing out in the morning and "rough" brake noise when slowing to a stop. My dealer service write up was: "Rear brake pads are stuck in holders due to rust build up. Rear brake rotors have severe rust on inside due to brake pads stuck in holders." They replaced the pads (04466-76012) and rotors (42431-12310) and "cleaned and lubed caliper slides."

    Following the link in post #7 to the CARspec entry, they recommend installing new shims and "fitment kit" in addition to pads & rotors. The picture shows pad holders/clips (fitment kit, fitting kit) that are black. Apparently mine were cleaned up, not replaced, and are a gold color so I assume they are zinc plated. Does anyone have more details on whether the corrosion protection on the pad holders has been improved since the 2010 originals? I'm considering proactively replacing them if that will make the brakes more robust to salted roads. I'm disappointed in hindsight that they weren't replaced at the last service since it seems the plating must be shot in that area if rust seized the old pads. Does anyone know if the shims have been updated or should be replaced as well? My brakes seem smooth and quiet so far (1 year) with the new pads and old shims. What would a be a reasonable labor time to replace these parts?
     
    #11 Jim T, Apr 21, 2015
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