Porsche Brembo 996 BBK Conversion-- let's figure out how to fix the dust boots/seals

[bavarian3]

Bringing this back up. I have a pair of rear calipers going on that I bought used in so-so shape. They definitely have miles on them due to the paint fading but the dust seals look good.

Does anyone think I should bother with a kit like this before refinishing and plugging them in?

[Nate047]

You probably don’t need new pistons, wouldn’t hurt though I guess just as long as those are known to be high quality and the exact right size with no variations. I would (and did) replace everything else if they’re in rough shape. Cross over pipes, bleeders, and pins included.

[OPS]

The only time I recommend replacing pistons is if they have scoring longitudinally beyond the piston seal or if there are any sharp edges which would cause failure (pitting ect).

Hope that helps!

[bavarian3]

You probably don’t need new pistons, wouldn’t hurt though I guess just as long as those are known to be high quality and the exact right size with no variations. I would (and did) replace everything else if they’re in rough shape. Cross over pipes, bleeders, and pins included.

Thank you.

The only time I recommend replacing pistons is if they have scoring longitudinally beyond the piston seal or if there are any sharp edges which would cause failure (pitting ect).

Hope that helps!

Do you ever see the piston seals fail? That's the main thing I was thinking to take care of while the calipers are detached from any fluid lines.

Any idea when the 28/30 seals kit will be back in stock?

[OPS]

I personally have never seen a piston seal fail. Failure will occur when the installation was incorrect (twisted or not seated correctly) or extreme lack of maintenance on the brake fluid. Met with Frenkit at PRI this last week and said I need the kits asap. They should be in Chicago on Friday however I am going to be on vacation spending time with my family until December 29th. I will be able to ship them out then.

Mike
OPS

[bavarian3]

OPS Tbonem3 heinzboehmer


Accidentally scuffed a couple of 996 pistons on disassembly. Wondering what everyone thinks here if this warrants replacement since this shouldn't pass through the inner seal.

If I do need to replace, would I need to replace on both calipers? (This only happened on one caliper.)

[maupineda]

I did the same, ended up buying new from centric as is a job I did not want to do twice, or worse still, have leaks or scratch the bores of the caliper. they are very cheap.

[OPS]

So those marks on the top of the bottom ridge (does that make sense?) will not contact your piston seal. They will cause friction on your dust boot however. I have definitely seen much worse but I agree with maupineda, not worth doing again or risking anything when it comes to breaking imho.

[Tbonem3]

Personally, I would take fine sand paper to them and send it.

[OPS]

Personally, I would take fine sand paper to them and send it.

I have done this also when the marks are above the piston seal.

Mike

[heinzboehmer]

+1 to replacing. I don't like the risk involved with safety critical components like brakes.

Also, forgot to update here. Bryson scoops slow down the cracking of the boots significantly, but unfortunately can't fix the small thermal mass of these calipers + pads. Cracking starting again:



I'll try the OPS boots next, if those crack, I'll throw these calipers off a cliff and get something more appropriate.

[bavarian3]

heinzboehmer Tbonem3 maupineda Thanks all.

I ended up ordering complete rebuild kits from OPS (BTW, are you Mike? Appreciate the prompt email support if so).

I'll be doing Megane RS fronts and 996 rear. Hate to tear them apart but I couldn't do the red. 😂

[OPS]

Yes thats me! Sorry the Megane calipers are new to me!

[heinzboehmer]

I'll try the OPS boots next, if those crack, I'll throw these calipers off a cliff and get something more appropriate.

Alright, Frenkit/OPS boots survived the 3.5 hrs of torture I put them through at Thunderhill on Monday. Pretty happy with that!

These boots are the only thing I changed since the last track day (which destroyed the GiroDisc boots), but here's a recap of the full setup:

• 996 calipers
• ZCP rotors
• PFC08 pads (at ~40% life left)
• GiroDisc titanium shims
• Bryson brake scoops
• RBF600

Hopefully these survive forever and I never have to swap another set of dust boots on these calipers.

[Nate047]

Alright, Frenkit/OPS boots survived the 3.5 hrs of torture I put them through at Thunderhill on Monday. Pretty happy with that!

These boots are the only thing I changed since the last track day (which destroyed the GiroDisc boots), but here's a recap of the full setup:

• 996 calipers
• ZCP rotors
• PFC08 pads (at ~40% life left)
• GiroDisc titanium shims
• Bryson brake scoops
• RBF600

Hopefully these survive forever and I never have to swap another set of dust boots on these calipers.

Details on the brake scoops? I feel like I read something else from you about those but can’t remember where or when.