When To Rebuild Stoptech?

[BryanL]

Has anyone ever rebuilt their stoptechs and replaced the piston seal? I have the seals and an anti knockback spring but don't have dust boots. Just wondering if it's needed if they aren't leaking and the pistons are easy to push back in for pad replacement.
If so how hard are they to replace and do you have to blow out one piston at a time by putting something to block the other pistons from popping out?

[Casey_SS]

I rebuilt mine a couple years back but I don't think they actually needed it. The seals weren't leaking and looked perfectly fine...I saved them for spares. The dust boots on the other hand, were completely melted and destroyed. I did not replace them and haven't noticed any problems from that. IIRC, the bigger trophy calipers don't even come with dust seals so...

Yes, you want to blow out the pistons against a block of wood or something. You also need an o-ring pick to get the old seal out and some way of capping the brake line so you can remove the caliper without having to bench bleed the master when it's all done. Getting all the pistons to go back in can be kinda tough but otherwise it's not too bad a job.

[Pranav]

x2 on what Casey said.

I bought mine used with a set of new uninstalled seals/boots from Matt and save for the dust seals looking a little cooked, there really was no need to replace the seals. Bores and seals came out fine.

If there is one thing you should do, get more of those wilwood bleeder screws we used at COTA on your rear brakes; they're the same thread on the stoptechs; this way you aren't wearing out the threads in the caliper body everytime you bleed the brakes. I replaced all 4 of mine before first install:

https://www.summitracing.com/parts/WIL-220-6069

I did also get the TI shields from Gyrodisc to help keep heat/crap away from my new dust shields:
http://www.girodisc.com/Girodisc-Titanium-Pad-Shields-for-Stoptech-ST40-Calipers_p_6587.html

If you do end up replacing your seals and stuff go with these guys:
https://www.zeckhausen.com/catalog/index.php?cPath=24&osCsid=6c0kpdl9lqkbsg9c1u8e603jd0

[Pranav]

I am also asking the zeckhausen guys on which type of floating rotor screws our stoptech kits came with. If they're the standard floating rotor screws I'm curious if we can see a benefit of going up to the MAX float screws at tracks like COTA:

https://www.zeckhausen.com/catalog/product_info.php?products_id=9780

[marshall_mosty]

x2 based on what Casey said.. Not a bad rebuild at all.

[BryanL]

Thanks dudes.

Pranav-I'm thinking mine has the max float race hardware but I'll verify tonight. Did you have a special bleed bottle or just an adapeter fitting clamped to 1/4" tubing for the smaller fitting with the wilwood bleeder screws? Do you think the shields do anything? I don't have ducts and don't think I have ever experienced any fade since I bought this car with stoptechs.

Now I just need one hub to replace and should be good to go next weekend after some more maintenance. But the hub and upper ball joints are in the trailer unfortunately. Anyone find an upper ball joint that will last?

[Pranav]

I just took some 1/4" hose and shoved it inside the 3/8" hose for my bleed bottle, works fine.

Ti shield Idk, thought it would be a good idea; ran them on my wilwoods that did have pedal/fade issues at COTA but that proved to be my fixed rotors and insufficient ducting. Was going to custom build floating rotors for the wilwoods till Matt sold me the stoptechs this year.

I figured the shields can only help so I got them again for the stoptechs.

[Supercharged111]

Do those knockback springs hurt you on the big end of a straight?

[BryanL]

No idea as I have never run them. Since replacing the rotors and upgrading the hubs I don't have an issue with knockback.