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Sticking Calipers = Smokey Brakes... EEK!


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Yeah... so i was driving to VT this weekend, and went down this hill.. you know.. no big deal... came to a stop sign, and BAM, there's smoke pouring out of my left wheel, so you know i stop, look at it, the wheel & brake system is pretty hot, all the other wheels are cool & not-so hot.

So, i've determined that my crappy gas milage, and rapid eating through of brake pads is this caliper.. not doing its job properly.

SOOO, the question is... do i pull the caliper, and try to clean it up myself, of should i just go get a re-man'd one... ORRR upgrade my front brakes to 2-pot calipers?

It's for the same ol' 97OBS 2.2L 4EAT 173k on her... you know the deal :rolleyes:

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I'm cheap.....so I'd start with the cheap solutions first.

 

First simply bleed the brakes to check the condition of the fluid (probably a mess with the overheating).

 

Then I'd disassemble the caliper assembly and see what is going on in there before throwing the whole thing away.

 

You could just a ultrafine sandpaper to polish out the inside of the caliper bore and the piston. If your seals are shot, then those need to be replaced.

 

I've found that the little metal plate shims behind the pads can sometimes weasel their way out from the pads and make the pad wear unevenly.

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And maybe it's just the slide pin that's corroded and needs a cleaning, polishing and relubing. Take a special look at the rubber bellows that protects the slide pin. Maybe it's ripped or dislodged and is letting water in. This need a special high temp grease found at any auto store.

Good luck!

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Someone on this board regularly rails against car manufacturers for continuing to feign ignorance on this issue ...oh wait, that's me.

 

Yup, nuttin' mportant - just one nem braken mechanismz. Reckon any ol' low-cost, mild alloy'll work as good as any other. :rolleyes:

 

**** ******!

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I put rebuilt front calipers (and new rotors and pads) on my car recently. They are very reasonnably priced when you take into account what they give you for the core.

Looking at yours, I think replacement with rebuilts would be more in line than messing with them.

Just my opinion.

Take care.

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I agree with frag, replace with rebuild, I have never been able to get the rubber boots to go in right when rebuilding.

I put rebuilt front calipers (and new rotors and pads) on my car recently. They are very reasonnably priced when you take into account what they give you for the core.

Looking at yours, I think replacement with rebuilts would be more in line than messing with them.

Just my opinion.

Take care.

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i had a caliper seize on my XT6 last year. turned out to be the parking brake was stuck on eventhough the handle was all the way down? i un-stuck it and worked it around and it's been fine since. just some random info since on the XT6 it's a front e-brake so that wouldn't be your issue.

 

what you might consider is that i ended up warping that rotor, so you might want to consider installing a new rotor while it's apart, they typically warp when that happens and they're driven on.

 

that is one rusty a$$ piston bore, crazy.

 

as a side note, i rebuilt some calipers over the past couple years, 3 sets of XT6 calipers and it was really easy. no complaints yet. two sets are on my XT6's and one set is on a friends. the rebuild kits were like $3 each!!

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The only thing I see "bad" in the picture is that the rubber dust boot has split. No biggie there. The rust on the inside of the piston isn't a real concern either. Rust on the outside of the piston or pits in the piston bore ARE a concern.

 

So lets think about this. What caused the caliper to get "stuck"? You've ruled out the sliding mechanism of the pins. That leads me to think about the hydraulic system since the operation is for the fluid to extend and retract the piston.....and it won't be able to do it if you have air in the system. And since you check your brake fluid routinely, you are sure that the fluid reservoir never got low enough to let air in the system.

 

So what gives??

 

Ahhhh....there IS one more component that would cause a brake caliper to "stick". And it's probably the LAST component you would think about!

 

When the flexible brake lines get old, they tend to collapse. Fluid pressure will allow the piston to extend, but the flexible line will not allow the fluid to retract the piston. Kind of like an artery if you eat a lot of fried chicken.:eek:

 

So go ahead and replace the flexible brake line on that corner as well.

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So lets think about this. What caused the caliper to get "stuck"?

I would have thought that torn piston dust boot made caliper grease beween piston and caliper body dry up, so it stuck. Just like it gets stuck if you tore guide pin dust boot.

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I am almost certain that i have a sticky caliper once and awhile. How do i get the top caliper bolt out? I have taken the bottom out no problem, but the top one has me stumped. Its not a hex or allen so wtf do you do?? I have asked this before with no replies.

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14mm bolt at the bottom, and swing it up. the top is a pin only. To get good clearance you may want to remove the caliper frame (I think these are also 14mm bolts in the front, but they may be 17mm) as well. If you are upgrading your brake system from a smaller stock set to a larger set (for more power. Also it can be good if you use oversized wheels) you need to get the disc and caliper frame from the same car.

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Careful -- remember that in '96 Subaru used two slightly different caliper designs on Outbacks. In early '96 (produced before June), the caliper does swing up on a pin -- you only have to pull the bottom caliper bolt and swing up the assembly to get to the pads. From June '96 on, they went with a different design, which has two bolts (upper and lower). I found this out the hard way, having to replace the right front caliper on my early '96 OBW recently. The Checker Parts guy ordered me a rebuilt -- but he got me the "new" one. No problem EXCEPT that the old and new pads are a slightly different form factor. The pad surface is the same area, but the steel backing plate is shaped differently and the old pads don't fit on the new caliper guides! Now when I want to replace pads, I have to buy one set of each -- and I aoutomatically get a set for my current replacement AND my next replacement.:banana:

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push the caliper arm towards the engine so to speak (away from you) and it'll slide right off the pin. clean up all the dirt and old grease and lube it good with new grease. the slide it back and forth a few times to spread the new grease around.

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yea yea, the upper pin is in fact a pin. How would you lubricate this pin?? Essentially what i am asking is, How do you take the caliper off ? does it just slide off of the pin?

 

At any auto part store you can get special high temp grease specialy for that application.

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