Last track event was cut short due to a sticky driver's side caliper that cracked a rotor and burned up the pads. Passenger side was fine. Disassembly revealed damage to 3 of the 4 pistons and caliper bores. Outside 2 pistons popped out pretty easily and the inside 2 required more air pressure and patience to free things up.

Is this caliper rebuildable? There is similar damage to 3 of the 4 bores.







Inside the bore, where brake fluid lives, is still smooth and I can't feel where the anodizing has rubbed away. Outside lip is not smooth and I believe did some minor piston damage (they are no longer smooth and have visible wear).

I know the pistons are trash, but what about the caliper? Can it be saved with some new seals?
What would cause this and how do I prevent it?

 

I wish I could see the pictures.

Dynalites don't have dust boots, does it look like brake grit or something got in there to damage the bores/pistons?

Summit sells replacement pistons, but they are ~$50. That's half a new dynalite, and you haven't even bought seals yet.

 

Pictures should be fixed.

I actually have a set of Dynapros coming my way so I'm not too worried about rebuilding this one. Definitely want to know how to prevent a reoccurrence though.

 

Yes, it's probably rebuildable. No, it's not worth it.

 

What could cause that to happen and how do I prevent it? I'd rather not buy new calipers every 3 years.

 

edit: oh no dust boots, that sorta makes sense

 

It's hard to say. One side of one caliper could be machining tolerances, bad luck, dirty fluid, debris behind that pad, combination of any of those, etc.

 

I was looking at some old threads and someone made a comment about "sav's black car" being a benchmark for whether something was worth doing. What is this black car and what kind of brakes does it run front/rear?

 

bad luck - check - blew the stock turbo at this event last year
dirty fluid - possible - it was leaking out the bleeder adapters earlier in the day
debris behind pad - likely from the leaky fluid

I was the guy that called you last Friday asking about fluid leaking out the bleeder adapter threads. Snugging them down did indeed stop the leak but it is entirely possible some brake dust filled fluid worked its way into the piston area and gummed things up.

After this incident I'm going to replace piston seals and bleeder adapter sealant every rotor change.

 

https://www.miataturbo.net/dynos-tim...q-17psi-49948/

https://www.miataturbo.net/media-53/...pgrades-42276/

https://www.miataturbo.net/media-53/...-thread-40699/

My old black '94 was sort of the benchmark for road race turbo cars from 2009 to 2011. When it last existed, it was on TSE gen1 11.75 fronts, 1.8L calipers on either 1.8L or Sport rotors (I forget which), and a Sport 15/16" master.

 

What brake setup are you running? For sure don't try to repair that caliper. At a minimum you need to replace that caliper, and figure out what caused this failure in the first place.

 

TSE 11.75" up front and sport brakes in the rear with Hawk DTC-60s all around.

I'm upgrading the fronts to Dynapro and going to try out the Performance Friction PF01/PF11 that seems to be the new hotness. Weight difference between Dynalite and Dynapro is significant, maybe twice as heavy. I guess that is the price you pay for a stiffer caliper.

 

<p>On a cleaning note, whats the best way to clean all the gunk/brake dust/etc when doing pad/rotor changes?</p>

 

Who told you that?

 

<p>Dynapro: 3.8lbs</p><p>Dynalite: 3.4lbs</p>

 

the internet.

 

Some jackass standing in the garage Sunday night holding both calipers. Clearly my hands need calibrated.

Very surprised there is only a .4lb difference. It sure felt like more. Although not going to complain!

 

According to my scale
Dynalite: 3.2lbs
Dynapro: 3.5lbs

 

0.3lbs sounds a little closer. IIRC the difference on my scale was ~4oz.