Why do brake calipers seize so frequently...? I never remember them failing like that in the past...

 

Is it just the way they make them nowadays or what?

 

 

I was wondering if buying a top-dollar one would be a good investment...

theirs really not much in a caliper. i work for a company that rebuilds them. i had a set that i personlly assembled on my subaru for years before i sold it and they are still doing good. somtimes the piston or bore gets rusty and they hang up but i have pulled them apart and cleaned them up with my dremel tool and reassembled and they work fine after. but that happens to all calipers not just the new ones

if it's the slide pins you have continuing problems with, maybe there's a 2-pot/4-pot swap from a WRX or ??? that could work on your car. No slide pins to rust.

if you have a newer-ish like 2003 model with the rubber bushings in the front brake slide pins, those swell and hang/seize all the time. i'm i the habit now of just throwing them away every single brake job i do, they're pointless and they seize all the time. fairly certain that brake jobs "encourage" them to seize. like making contact with new grease or something makes them swell.

 

at least in the rust belt, the caliper slide pins need cleaned and greased far more often than the pads need changes - so that's the problem in the rust belt, no one is doing that. i check them every time i'm in there with the wheel off for something else....and i'm often thoroughly surprised at how dried up and non-lubed the slide pins are after I had done them not long prior. usually they can use a clean up and regrease even though the pads are nowhere near needing replaced.

 

add to that mechanics/shops that don't clean/regrease or buying used calipers that are likely contaminated and it compounds the issue.

 

*** I have seen it mentioned on other forums that the grease used from the factory is very high quality stuff that lasts a long time, but it's hard to get - I don't recall anyone knowing where to get the stuff. But the stuff you get in the store is not nearly as good. I've seen folks trying to nail down where and how to get that factory stuff because it lasts so long.

For calipers that float on rubber sleeves (boots) over the pins: I believe one reason they seize is that the bores for the sleeves in the caliper body rust on the inside, squeezing the boot inwards against the pin. The countermeasure is to remove the boot from the hole (not always done, because there's no movement at that interface), remove the rust, and apply grease. That is, the boot needs to be greased both inside and outside, even though the sliding happens only on the inside. One suitable tool is Dremel with a drum attachment, which is what pamike likely refers to.

Machining tolerances and choice of materials may also play a role. The very simple Kelsey-Hayes calipers on my minivan (sliding on two identical boots) passed the "move by hand" test every time I checked.

Edited October 13, 201213 yr by avk

You can also get replacement sliding pins. If the calipers are cleaned, lubed, and the boots replaced if broken, there really isnt a reason they should seize for quite some time, if at all.

well that must be the way labor works around here.

 

I guess they cut corners knowing it will lead to more business. There really isn't much I can do even if I have a real case...they really are very stubborn about doing it 'their way'.

 

If I had my way I'd take it into Midas or one of those specialists but they really are much too expensive...I think they want like $350 for a single rotor or something...

 

It was only 60 bucks for a new caliper anyway... :-/

 

Cheers!

 

--Damien

This is the stuff you want for those rubber bushings on the caliper lock pin. They're also generously smeared on the piston boots prior to assembly at the factory. The stuff holds up, whereas everything else I've tried has vaporized under the heat and stress of braking components. In addition, they've gummed up and and swelled the rubber bushings that grossgary mentions.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=128421&highlight=niglube

Edited October 14, 201213 yr by hohieu
clarity

well that must be the way labor works around here.

 

I guess they cut corners knowing it will lead to more business.

in their defense they aren't doing it to "make more business" in the sense you may mean. if they start "doing it right" - then they also need to charge more to make up for more time, more supplies, and fewer jobs getting done. so they might be pad slapping to keep things moving and their prices in line with everyone else and what the locals want to pay...but not just to hose them and "bring them back".

This is the stuff you want for those rubber bushings on the caliper lock pin. They're also generously smeared on the piston boots prior to assembly at the factory. The stuff holds up, whereas everything else I've tried has vaporized under the heat and stress of braking components. In addition, they've gummed up and and swelled the rubber bushings that grossgary mentions.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=128421&highlight=niglube

 

 

this still cracks me up;

 

Quote:

Originally Posted by porcupine73

Rubber grease! I think something is lost in the translation....... It may be made by a joint venture between Matsumura Fishworks and Tamaribuchi Heavy Manufacturing Concern.

 

 

It is very disrespectful to friction, and will banish it to the land of Wind and Ghosts!

two words - Plumbers grease.

 

I use the plumbers grease, which is a silicone based lubricant, to lube up the slide pins on my brakes. It lasts longer than the stuff they sell at the autoparts store, is waterproof, and does not cause the rubber boots to swell & cause binding. (also useful on O-rings)

 

I had to replace the pins & boots on my car due to neglect by the po. Used the plumbers grease on them during installation more than 3 years ago, and have not had any problems with the pins trying to seize. I do relube when I do a pad replacement, just to make sure, but in my experience, there was still plenty of lube on the pins after more than a year.

I must admit I have NO IDEA how it would hold up in 'the rust belt' but, this is what was recommended on another board so, I bought some and have been using it successfully;

 

thanks luckytexan, that looks good for me to try. where did you get it, i don't recognize seeing it before.

thanks luckytexan, that looks good for me to try. where did you get it, i don't recognize seeing it before.

 

got mine from Amazon IIRC. Probably available locally but I was buying other stuff at the time. The bottle is probably a lifetime supply for me. There's a brush built into the lid.

 

 

decent reviews and one guy seems to feel it will protect well in winter;

 

http://www.amazon.com/Permatex-24125-Ceramic-Extreme-Lubricant/dp/B0018PSASU/ref=cm_cr_pr_product_top

 

 

again, dunno personally how it would stand up in snow States. But 2 or 3 gurus at nasioc seem to like it.

 

 

along with nipper's comment, no grease is gonna make up for rust. emery cloth/scotchbrite the surface of the pins or new slider pins might be required once a little corrosion 'bites' into the metal.

Edited October 15, 201213 yr by 1 Lucky Texan

That looks like a great idea...I wish I could make suggestions to my mechanics like that... :-(

Another 'stupid idea' that just might work is WD-40. I have a Sube that just sits in my driveway. It showed up one day...and now it doesn't want to leave (it loves being around other Subarus).

 

The pad would rust right into the caliper from just sitting there for so long...I tried to move it one day...but one of the wheels simply would not unfreeze...no matter what I would do. I sprayed a copious amount on the assembly...and it popped right loose!

 

 

Just $.02 that may someday be worth $200.

 

--Damien

Another 'stupid idea' that just might work is WD-40. I have a Sube that just sits in my driveway. It showed up one day...and now it doesn't want to leave (it loves being around other Subarus).

 

The pad would rust right into the caliper from just sitting there for so long...I tried to move it one day...but one of the wheels simply would not unfreeze...no matter what I would do. I sprayed a copious amount on the assembly...and it popped right loose!

 

 

Just $.02 that may someday be worth $200.

 

--Damien

 

 

glad it worked but, over half of WD-40 is 'stoddard solvent' (you can think of it as a sorta deodorized kerosene) and I dunno how it could affect binders in pad material. seems risky

 

maybe pads with different technology would help? if the pads on there now are semi-metallic, maybe switching to ceramic (like Centric posiQuiet Ceramic) or even para-aramid (StopTech Street performance) would stop the rust-welding problem.

Do ceramic pads generate less heat?

Do ceramic pads generate less heat?

 

as far as 'generate' I have no idea. pretty much, pad materials are all a bunch of compromises - do you want good modulation?, yeah, but you don't want to give up longevity. Do want great high temp operation? sure, but not if I have to give up good bite at 10degrees F. Do you want less dust? yeah, but not if it means they might squeal. Do you want the pads to last forever? Yeah, but not if they eat the rotors in 4 months.

 

all brakes change your car's momentum into heat (plus a little dust - most from the pads, some from the rotors))

 

one thing is, if someone goes into a parts store and asks for the cheapest pads they have, they will sell that person crap that is scary to drive with. I could see that happening with cars right before they get sold; "give me the cheapest pads and belts you have", then, the next owner has a belt break at 25K and brakes that are gone 5K later.

Edited October 17, 201213 yr by 1 Lucky Texan

Do ceramic pads generate less heat?

 

No, they can just handle a higher heat load.

When I did my brakes Mine were smoking but mine was not because of the slide pins but because of the pistons, I'm sure it's been said here but I think it had to due with the last owner not flushing the system..

 

The passenger side was the worst, after driving my rotor temp was very close to 600F in some spots it went higher then my gun's temp.

 

I tried to get the piston out with the air compressor.. Long story short a shot of 125 PSI to the brake line hole was still not enough to push the piston out.

 

I ended up getting a loaded caliper off Amazon for like $26 or $35 powder coated it black (took it all apart) and did my stuff.. but that's extra because I will be running open wheels in the summer.

I just remember the three other cars (plus a truck) I've owned and I never remember them failing like that....

 

It could be a metal issue, too....poor metallurigal processes...low quality ore...etc .etc. Maybe recycled steel is lousy...maybe they mined the wrong hill.

 

I remember rotors they used to import here from China about a decade ago used to rust very rapidly...once it got pitted it was only a few months before they were shot.

 

--Damien

No, they can just handle a higher heat load.

 

And does not give that warped rotor feeling

I use antisieze on the slide pins as regular brake silicone will gum up after heat cycles and cause the slides to stick. I also put antisieze on the backs of the pads where the caliper contacts them to help with noise.

 

Most shops will not lube the slides usually when doing a brake job. Heck, even the lube that comes in the new calipers can eventually gum up and stick.

When I press the pistons back in, I always crack the bleeder screw in order to get the old fluid out of the caliper. This can also help prevent the pistons from sticking and is usually the easiest way to know if you're having an issue inside the caliper.

Hmm. lets see. will a 125 PSI air compressor pop a frozen piston, that has seized completely?

 

Force at the pedal, maybe 50 lb from your leg (low estimate). Maybe 5:1 ratio on the brake pedal = 250 lb. Say a 1" master cylinder piston, call it 1 square inch (actually less than 1" dia, so pressure will be higher). So that is 250 PSI already. And these are just rough, conservative guesses, brake pressures can get way higher than this. (I also ignored the brake booster.)

 

So a frozen piston probably isn't going to move if you put air pressure on it.