Nice. My car is at ASG.

[arob]

Last weekend at PorscheFest, the Day 2 tech inspection found I was low on brake fluid in the MC. Fine - top off, drove day 2 and 3 with no issues. Check the MC Tuesday night, and find that I'm low again. A little intArweb research indicates that my MC seal may be heading south. Fair enough, the car is 27 years old, and there is no paperwork indicating replacement of it in the documents that I have. I call T on Wednesday or Thursday to let him know what I'm experiencing.

Drove the 911 to a friend's house in Sterling from Herndon Saturday morning to help bleed the brakes on his A4 in prep for his trip to Watkins Glen. 30 minutes later, the A4 is off the jackstands, tools are gathered to load into his truck (which is parked down the street with a trailer already hooked up), and we're ready to head off to Solomon's Island to do some fishing.

Walk out to the driveway, and both front wheels on the 911 looked like they pissed themselves. Further inspection revealed that the pistons are leaking fluid as well. Nice. I did notice that while driving there, the pedal was tight at first, then would slowly start falling to the floor. Good thing I wasn't doing any spirited driving at the time.

We go fishing, catch a sh!tload of rock fish, drive back to Sterling, pick up truck, drive back to my buddy's house, load 911 on trailer, drive to shop, dump car, and all is well. Topped off the MC one last time for good measure. While loading the 911 onto the trailer, it was bad enough where I was using the parking brake now, while positioning the car onto the trailer.

What are the chances that I may have caused this during PFest? Perhaps I didn't cool the brakes down enough during cool-down laps? Was the first indication that the R front caliper was grabbing after I swapped in the PF97's the week before? The grabbing eventually went away by Day2 of PFest. Just seems odd that the MC and both calipers go bad w/in days of each other.:?

Thoughts are appreciated.

[}{arlequin]

Just seems odd that the MC and both calipers go bad w/in days of each other.:?


i'd say that's EXACTLY the kind of failure you should expect (and want) after a trackday. both failed b/c both have never been subjected to this kind of stresses, thermal and mechanical, while being decades old.

lots and lots of heat + old, cracked and worn rubber seals = fail.

it's nice they all crapped out same time this way you can do all 4 calipers and the mc and know that you'll won't be revisiting this issue for another few years.

[Trak Ratt]

Sorry to hear about this. But wait there’s more! Agree with }{ about nows the time but this is going to be a major financial hit! Figure $1K when all is said and done (4 calipers, master & ??? + labor) Be sure to have them adjust your peddle WTIT and use Blue or Gold.

[cmartin]

Are you sure the MC is bad? I'd start with news seals in the calipers and see what happens. I'd rather spend ~$50 to rebuild the calipers first. :)

[arob]

Thanks for the input, all. I'm not certain that the MC is toast, but here's my support to my assumption:

A couple days before the tech day at HBL, I swapped in the track pads, and decided to do a full flush. The L rear caliper kept showing air in the line, even after a good 1/2 bottle of Gold. I found a thread on here spot on to what I was experiencing, and assumed that this was my issue as well. Turned out a "main rear seal" (or something like that) had gone/started to head south.

When I returned home Saturday night / early Sunday morning, I checked the garage floor to make sure it didn't start dumping fluid then. The floor was dry and spotless. :-/

[}{arlequin]

that's the catch... you rebuild calipers = $50
shop rebuild calipers = $1050

i still would do the mc as well. after all, in a $1k-sized bill, what's $200 more? also, if you diy and the bill is $50, you'll gladly pay $250 instead of a $1k anyway.... win-win :D

if it's the first time the brakes were used in such a way, it's feasible that the pedal got mushier and actually sank a little deeper as the weekend went on. once you push the pedal further than normal, the 'dirty' part of the mc's piston starts scraping the mc seal thus helping its demise. while all the brake fluid is gone and you will have to start from scratch, i'd all of it at once. why bother introducing air into the system 3 months from now?

while doing the mc, i'd rebuild the pedal cluster too.

[arob]

while doing the mc, i'd rebuild the pedal cluster too.

Thanks }{ - I was afraid of there being a "WYIT" connection to this. Well, I was just trying not to think about any "WYIT" types of things to tack onto this project.

The car is already at the shop, it was broken down in Sterling, although in my buddy's garage, neither of us have any knowledge in rebuilding calipers or replacing the MC, so I'll take the hit this time, but hope to attend upcoming wrenching sessions to learn to do some stuff on my own.

Don't get me wrong, I'm not complaining that this happened, for I knew what I was getting into when I purchased the car.:oops:

[Jazzbass]

Are you sure the MC is bad? I'd start with news seals in the calipers and see what happens. I'd rather spend ~$50 to rebuild the calipers first. :)
Yes. The calipers may be shot, but it's easy enough to spend $50 on rebuild kits to find out first. If they are shot, then buy new ones. And buy Carrera calipers, not SC calipers. Same price, upgrade in braking.

[smdubovsky]

If you buy carrera calipers, dont forget to buy the carrera rotors too;) One doesn't work w/o the other.

FWIW, if you can bleed brake & change pads, then you could likely rebuild calipers. Its more a messy excercise in patience than actually being difficult.

SMD

[Rick Lee]

I had fluid spraying out of my SC wheel wells. I rebuilt the calipers the following morning and had done my second bleed the following day. All fixed. Cost me about $48 in parts, plus two cans of ATE Blue. It was very easy.

[Trak Ratt]

Actually the front Carrera calipers will work just fine with the SC rotors. As Jazz knows the real brake upgrade is in the rotors. The calipers just need to be wider to fit over the 4mm thicker Carrera rotors. The front caliper pistons on SCs and Carreras are the same size = same clamping force. Thicker rotor = bigger heat sink. Only difference is in the spacer between halves. If you’re replacing front SC calipers anyway why not replace with Carreras. Good to replace rotors at the same time but not hyper critical if $$$ tight. Don’t let your pads wear down all the way, that 2mm a side has to come from somewhere. Rears a little more tricky cause Carrera pistons are bigger. Porsche adds brake bias valve in system to compensate.