Never seen this before. Both were like this when I overhauled the brakes on the Dakota this weekend. I'd think the bores would be strong enough not to chip off. Not really looking forward to replace both. I was thinking it should be ok since it doesn't extend back past that point. Anything I could be overlooking?
Brake caliper oddity
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Those look like phenolic pistons so they're hard but probably not as hard as steel.
Because it's on the edge and it chipped off, I wonder if something harder than it like a pebble wedged itself between the face of the piston on that area and the pad. Then when you used the brakes, it compressed and since it couldn't break the pebble or embed it due to its hardness, it just chipped off to relieve the stress.
Or maybe it was a weakness caused during the manufacturing or installation process (was this a reman?) and eventually over time the constant compression and release and heat cycles caused it to chip.
Because it's on the edge and it chipped off, I wonder if something harder than it like a pebble wedged itself between the face of the piston on that area and the pad. Then when you used the brakes, it compressed and since it couldn't break the pebble or embed it due to its hardness, it just chipped off to relieve the stress.
Or maybe it was a weakness caused during the manufacturing or installation process (was this a reman?) and eventually over time the constant compression and release and heat cycles caused it to chip.
That's not the bores. That's the caliper piston. That one is made of phenolic/bakelite type of composite material. Sometimes they were notorious for swelling up and causing them to stick and not let the pressure off the pad completely and cause premature pad wearout/brake failure. I personally don't like them.
Did they push back easy with your c-clamp? If they did, you're probably OK. If not, get rebuilt calipers. The chip isn't bad enough to warrent changing unless they don't push back easy.....
EDIT: Went back and took another look. The edge of that chip is going to be awfull close to the caliper/piston o-ring seal when that piston is fully compressed. Most likely got chipped when someone took something and pushed them back during a previous brake change. That chip will also allow moisture/contaminates to get into the phenolic as the hard smooth surface is missing. Others may disagree, but If it were mine, they'd be gone IMHO.
Did they push back easy with your c-clamp? If they did, you're probably OK. If not, get rebuilt calipers. The chip isn't bad enough to warrent changing unless they don't push back easy.....
EDIT: Went back and took another look. The edge of that chip is going to be awfull close to the caliper/piston o-ring seal when that piston is fully compressed. Most likely got chipped when someone took something and pushed them back during a previous brake change. That chip will also allow moisture/contaminates to get into the phenolic as the hard smooth surface is missing. Others may disagree, but If it were mine, they'd be gone IMHO.
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Originally Posted by jetmech1
That's not the bores. That's the caliper piston. That one is made of phenolic/bakelite type of composite material. Sometimes they were notorious for swelling up and causing them to stick and not let the pressure off the pad completely and cause premature pad wearout/brake failure. I personally don't like them.
Did they push back easy with your c-clamp? If they did, you're probably OK. If not, get rebuilt calipers. The chip isn't bad enough to warrent changing unless they don't push back easy.....
EDIT: Went back and took another look. The edge of that chip is going to be awfull close to the caliper/piston o-ring seal when that piston is fully compressed. Most likely got chipped when someone took something and pushed them back during a previous brake change. That chip will also allow moisture/contaminates to get into the phenolic as the hard smooth surface is missing. Others may disagree, but If it were mine, they'd be gone IMHO.
On an 18 year old car? Please.
That's not the bores. That's the caliper piston. That one is made of phenolic/bakelite type of composite material. Sometimes they were notorious for swelling up and causing them to stick and not let the pressure off the pad completely and cause premature pad wearout/brake failure. I personally don't like them.
Did they push back easy with your c-clamp? If they did, you're probably OK. If not, get rebuilt calipers. The chip isn't bad enough to warrent changing unless they don't push back easy.....
EDIT: Went back and took another look. The edge of that chip is going to be awfull close to the caliper/piston o-ring seal when that piston is fully compressed. Most likely got chipped when someone took something and pushed them back during a previous brake change. That chip will also allow moisture/contaminates to get into the phenolic as the hard smooth surface is missing. Others may disagree, but If it were mine, they'd be gone IMHO.
On an 18 year old car? Please.
I would replace. Brakes are not worth it. Plus the time if you have to take it apart again later. I like to do a brake job right and not have to worry about it.
EDIT. I've never tried rebuilding a caliper with a kit. I've always wanted to. If i had a piston like that i might try it.
EDIT. I've never tried rebuilding a caliper with a kit. I've always wanted to. If i had a piston like that i might try it.
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Not the original owner. That explains a lot! I didn't know they used different material. All the remans are the same. The drivers side was easy and don't have problems with that side. The passenger side is another story. I thought it was the rotors and pads but that caliper wasnt easy to push back in! Supposedly it's a new one.. still has a sticker on it. I didn't do it so don't know. Picked up another one on the way home. Just hope it didn't ruin the new pads and rotor. Thanks for the all info learned something new!
Originally Posted by spasm3
I would replace. Brakes are not worth it. Plus the time if you have to take it apart again later. I like to do a brake job right and not have to worry about it.
EDIT. I've never tried rebuilding a caliper with a kit. I've always wanted to. If i had a piston like that i might try it.
It's pretty fun man! I've done all four on my car. Get a decent caliper from the scrapyard, you don't have to worry about plastic pistons rusting or losing their plating. It's a little hard to get that dust boot on but you'll figure it out.
I would replace. Brakes are not worth it. Plus the time if you have to take it apart again later. I like to do a brake job right and not have to worry about it.
EDIT. I've never tried rebuilding a caliper with a kit. I've always wanted to. If i had a piston like that i might try it.
It's pretty fun man! I've done all four on my car. Get a decent caliper from the scrapyard, you don't have to worry about plastic pistons rusting or losing their plating. It's a little hard to get that dust boot on but you'll figure it out.
Originally Posted by spasm3
EDIT. I've never tried rebuilding a caliper with a kit. I've always wanted to. If i had a piston like that i might try it.
I rebuilt mine without a kit (though if I'd had a kit I'd have used it). Just cleaned and lubed and put it back together.
Quite satisfying, but I wasted A LOT of time following the internyet advice to blow the piston out with compressed air, before using the brake pedal.
DUH!
I doubt a standard kit includes new pistons, though, which it'd need in this context.
EDIT. I've never tried rebuilding a caliper with a kit. I've always wanted to. If i had a piston like that i might try it.
I rebuilt mine without a kit (though if I'd had a kit I'd have used it). Just cleaned and lubed and put it back together.
Quite satisfying, but I wasted A LOT of time following the internyet advice to blow the piston out with compressed air, before using the brake pedal.
DUH!
I doubt a standard kit includes new pistons, though, which it'd need in this context.
Hang on. This is a 19 yr old truck. Need more info. How were brakes working before you took the pictures? I haven't encountered a plastic piston yet. Would JBWeld stick to it? If the caliper isn't weeping brake fluid.. What sort of use does truck see? I went with a set of re-mans from Auto Zone for the Rat 6yrs ago. 25$ each less 6$ for cores. Prolly have less than 5k miles. on them . Which is the worst for brakes. I may try filling in the edge and filing the cured epoxy down even. Mostly so it would seal better against dust boot. Pads look fine. How are the brake lines and hoses? Did the damage happen from pliers? Do nothing,repair or replace depending upon usage. I use Sil-Glyde when fooling with calipers. Gives enough slip to set pistons with your thumbs. Great for slides and boots too. I'm sure there is other stuff you can use too. I've had a tube for 15 yrs.
I changed the rotors/pads because it would shimmy when it got hot. Typical warped rotor I thought. Prior I had lubed both sides since also the calipers were sticking... I have a tube of the syn-glide also. I'm guessing that's all it was after, the pads were thin though. The lines seem ok.. I flushed it recently also. I'll repost with the results hopefully tomorrow.. I had enough bad luck with car repairs lately. The tuneup on the old truck went good though!
No way, no how, do I reuse those calipers. Rebuilds are what, $30-$60 or so? CHANGE them out!!
An 18 year run on a set of calipers was a good long run. Time to replace.
An 18 year run on a set of calipers was a good long run. Time to replace.
Originally Posted by bubbatime
No way, no how, do I reuse those calipers. Rebuilds are what, $30-$60 or so? CHANGE them out!!
An 18 year run on a set of calipers was a good long run. Time to replace.
Unless I missed it we know nothing about the state of the calipers. No pictures, no statements, no nothing.
I got a load of similar static on here when I posted I was taking mine apart, and they cleaned up fine.
http://www.bobistheoilguy.com/forum...ng-front-drivers-side-brakes#Post4031331
Probably original so about 30 years old at the time, having seen serious neglect in high humidity Taiwan.
Unless you try, you don't know.
(If you can't be bothered then that's another matter.)
No way, no how, do I reuse those calipers. Rebuilds are what, $30-$60 or so? CHANGE them out!!
An 18 year run on a set of calipers was a good long run. Time to replace.
Unless I missed it we know nothing about the state of the calipers. No pictures, no statements, no nothing.
I got a load of similar static on here when I posted I was taking mine apart, and they cleaned up fine.
http://www.bobistheoilguy.com/forum...ng-front-drivers-side-brakes#Post4031331
Probably original so about 30 years old at the time, having seen serious neglect in high humidity Taiwan.
Unless you try, you don't know.
(If you can't be bothered then that's another matter.)
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I would replace the calipers.
Passenger side has been replaced.. no issues now. I'm
guessing that prior reman must of been overheated causing the piston to stick. I could tell a big difference just putting it on. If the other caliper starts to cause problems I'll replace it also.
Now to replace the lower ball joint.. Firestone's definition of it needs to be replaced but not now needs some work.
guessing that prior reman must of been overheated causing the piston to stick. I could tell a big difference just putting it on. If the other caliper starts to cause problems I'll replace it also.
Now to replace the lower ball joint.. Firestone's definition of it needs to be replaced but not now needs some work.
I had an Autozone reman that seemed to drag right out of the box. I wound up ordering a Raybestos off Rockauto after advisement here. Not all remans are bad but enough of them sure seem to be. One of these days I should look into proactively buying rebuild kits (not much to these things after all) for my vehicles and having the parts on the shelf, assuming it's not big money.
After driving it to Lowes still smells on the drivers side like it's dragging.. Sounds like I need to replace that one also. So replace the calipers every brake job? Good ole Dodges...
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