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Looking for a brake piston rebuild kit for OEM calipers - anyone know of one?

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Brookeville
#1
Hey guys,

So I am looking for a brake caliper piston rebuild kit for my 2014 FiST. When I swapped pads a few weeks ago I noticed some fluid leaking from around the dust boot seal around the piston. When I swapped back to my OEM pads last week (after a weekend at the track) I noticed that the boot had been pinched/stuck to the back of the hot, hot pad and had melted/torn about 2". I need to rebuild the seals and when I contacted my local dealer (via FordParts.com) here's the reply I got:

Response:

GOOD AFTERNOON SIR, FORD no longer services brake calipers like that you must buy complete caliper.
The thought of having to buy a replacement for $121 + S&H makes me cringe when all it needs is a couple of seals and some TLC. Could anyone please recommend a source for a seal kit that will work for these calipers? Surely someone has had some luck with something out there.

TIA!
 


D1JL

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#2
I tried getting kits for my '11 Fiesta SES and found that were not available.
All that could be done was to get replacement calipers.
You may find the same problem with the ST.
Try Steve at Tasca Parts 800-598-1484



Dave
 


OP
sluggyjunx
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Thread Starter #5
Caliper rebuild, take one

Time passes...

And I'm circling back to follow up on this. I finally got around to getting the caliper off and taking a stab at rebuilding the front left caliper and so far it's looking promising. Here's what I've done:

Purchased the front caliper rebuild kit from RockAuto; it's Carlson part # 15149, $2.73.



Caliper removal is pretty straightforward. I used a finger from a nitrile glove and a zip tie to seal off the brake hose once detached. Reminder: when you pull this hose out, about 3/4 of a cup of brake fluid will immediately drain out of the back of the caliper; have your drain pan ready! Once on the bench I could get a look at the damage, namely the melted/torn dust boot. To remove the caliper, position a piece of ~3/4" thick wood in the caliper and your air hose with a plastic/rubber nozzle on the back side of the caliper like so:



Wear eye AND ear protection. Keep your fingers CLEAR and apply a small amount of compressed air. The piston will pop out with a BANG! (I warned you) :)



Here's the torn boot:




The inner bore; looks fine. Some minor wear, minimal rust, corrosion. Cleaned grooves up with a pick, pocket screwdriver, steel wool, soft bristle brush, paper towels, etc.



Piston has some very minor scoring and crud that cleaned right up. I used a citrus de-greaser, pocket screwdriver, pick, plastic bristle brush, steel wool and paper towels on this.






Ready to go back in



Used a very small amount of 3M Silicone Paste to lubricate and work the rubber dust boot. Just put a tiny dab on my finger and wiped it around the rubber to lubricate it. Repeat. Filled a bottle cap with brake fluid and lubricated the square o-ring seal. Poured a bit of brake fluid into the grooves in the caliper and spun it around to work around the grooves, and used my finger to be sure there was a liberal amount of fluid coating the inner bore. I installed the square cut seal and the dust boot to be sure they were well-seated in the grooves. Next, I used a trick I learned from my fav online mechanic, Eric O. from SMA - here's how he installs (or tries to install) the piston. For me, it worked like a charm. Just remember to wear eye protection and keep your fingers clear. The rubber boot pops on to the piston. Then, using a good bit of force, press the piston back into the bore. It should fit very snugly! If you're having trouble, pop it out and lubricate it more with a few drops of brake fluid. Make sure it's well lubricated so it doesn't damage the square cut seal. Once installed be sure to check the dust boot seal all the way around to be sure it's seated properly and not pinched anywhere!




That's about it for now, folks. I am headed to the parts store to pick up some copper crush washers to reinstall the brake line and will perform a full brake bleed after that. Any questions, throw 'em at me. I'm not an expert, and this was my first rebuild (ever!) and it was FUN to do. If the seal leaks and I can't get it to work properly, I'll probably just buy a new caliper and call it a day. But, I've learned a lot going through the rebuild and so far it's looking good. We shall see! Good luck! [cheers]
 


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#7
This couldn't have come at a better time! My stock caliper's dust boots are mangled from track use and need to be rebuilt before I chuck them on the car for winter duty. Thank you sluggy!
 


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sluggyjunx
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Thread Starter #9
I'd like to do a quick follow up. I spent the day at Summit Point with Track Daze two weekends ago with the FiST and had a blast. (Was placed into Yellow group for the first time; solo, pass anywhere with a point by. I got lots of practice giving points!) The brakes held up perfectly well through four 30min sessions. I didn't experience any issues so I'd say the rebuild kit was a success. Good luck, everyone!
 


LilPartyBox

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#10
I usually do a caliper rebuild every 2 years or so. I just assumed parts would be readily available for us. Thanks for doing the leg work and great write up!
 


CSM

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#12
Nothing else to add except I also had a leaky front right piston at 30k miles on my 2014. In my case the piston itself had built up so much rust the O-ring had stopped doing a good job of sealing. I ended up buying a new gasket kit and a new piston. All is good now.

I think Ford really went on the cheap with the brakes on our cars. I've owned a lot of cars over the years and I've never seen leaky pistons at 30k miles.
 


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#14
Anyone ever rebuild a rear? PO put some nice scoring in the rear piston face, when they didnt line up the nub on the pad with the rear piston slot.
 


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sluggyjunx
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Thread Starter #15
What size were the crush washers?
I can't remember exactly off the top of my head, but I measured, pondered, worried and searched for hours to try to figure this out. Eventually I purchased this: https://www.amazon.com/gp/product/B06Y1HQ1MF/ref=oh_aui_search_detailpage Which has the proper size in it. You can go buy an OEM washer or a couple from the parts store, but the value you get from buying a bulk set is fantastic. GL!
 


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Bend, OR, USA
#16
Thanks for putting together this how-to, @sluggyjunx . I just picked up a FiST and will be doing my first track day, and I know the brakes are going to take a beating since I had nothing but problems with the 6-pots on my '18 STi. It's great you did all the research so I know what to do when it comes time for a caliper rebuild. (y)
 


OP
sluggyjunx
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Thread Starter #17
Thanks for putting together this how-to, @sluggyjunx . I just picked up a FiST and will be doing my first track day, and I know the brakes are going to take a beating since I had nothing but problems with the 6-pots on my '18 STi. It's great you did all the research so I know what to do when it comes time for a caliper rebuild. (y)
Thanks for the kind words. Let me give yet another follow-up! Since posting this, I've been on track a few more weekends. The dust boot has failed again. I spoke to various techs with NGP Racing and they all echoed the same thing when I asked what I could do with my stock brakes - eg, are there any "high performance" dust boots out there? All of them said "no." Essentially they indicated that a big brake kit would be the best way forward if I was going to track frequently. Rebuilding the calipers after each track weekend is not something I'm interested in doing. For now, I'm leaving them be, but I will be exploring the BBK in the future should I decide to track more.

Note: currently my transmission is on my workbench. Car has been out of service since running at PittRace in May. I'm rebuilding the trans after having the dreaded whining/grinding from the bearings. Ugh. So I'll be out of commission for at least a few weeks. Fingers crossed...
 


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#18
Thanks for the kind words. Let me give yet another follow-up! Since posting this, I've been on track a few more weekends. The dust boot has failed again. I spoke to various techs with NGP Racing and they all echoed the same thing when I asked what I could do with my stock brakes - eg, are there any "high performance" dust boots out there? All of them said "no." Essentially they indicated that a big brake kit would be the best way forward if I was going to track frequently. Rebuilding the calipers after each track weekend is not something I'm interested in doing. For now, I'm leaving them be, but I will be exploring the BBK in the future should I decide to track more.

Note: currently my transmission is on my workbench. Car has been out of service since running at PittRace in May. I'm rebuilding the trans after having the dreaded whining/grinding from the bearings. Ugh. So I'll be out of commission for at least a few weeks. Fingers crossed...
Thanks for the update and sorry to hear about your transmission. Please follow-up when/if you decide on a BBK. I went that route with a '09 WRX I had and got a Stoptech ST-40(?) package. I'm not sure I want to spend that much money on the FiST considering prices are around $2k but maybe it's worth it in the long run. Wilwood is the cheap option but I hear replacement rotors are pricey. I need to do more research but I've got plenty of time since the track season is over for me now.

But I will say the stock brakes survived my first track day. The boots are still intact but that was my first time ever running a car like this after a few years of AWD Subarus so I wasn't pushing that hard. I was running a lot faster in my last session of the day and burnt the paint off the back of the pads (Hawk DT-60). I bet if the daytime temps were warmer and I had a couple more sessions the boots would have started to get crusty. The caliper paint did start to darken a bit where the pads touch. Oh well!
 


SST

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#19
so if there aren't any performance dust boots out there, how can a BBK survive the heat? I heard wilwood dust boots fail easily too.
 


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#20
so if there aren't any performance dust boots out there, how can a BBK survive the heat? I heard wilwood dust boots fail easily too.
Of course it all depends on the track, the driver, and other factors but I would expect the boots to last longer. They shouldn't see as extreme temps as running the cute little stock brakes on the track and the boots in a BBK are likely more heat resistant. The boots in Brembos and StopTechs I've had looked much higher quality than the soft and squishy rubber on my FiST. But I will say that my last set of Brembos were cracking after 2 track days. So you're right, they'll likely all eventually fail.

FWIW, my plan is to run a BBK during the summer months when I'm doing track days and swap back to the stock calipers and rotors for the winter. That way I can do an annual rebuild of the calipers and do it when there's a couple feet of snow on the ground and I have loads of free time.
 


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