rebuild, replace?

[Mackpipes]

This past weekend's DE was an absolute blast! Learned alot, and took the advice of APKhaos to start breaking like a man. Well, if breaking like a man entails boiling my break fluid and frying the seals in my rear calipers, mission accomplished. :lol:
On my way home from the track I noticed the car dragging a bit. It turns out my left rear caliper is dragging a piston. :x On the advise of a local shop, (to remain unnamed) replacing the rear calipers was the sound thing to do, rather than rebuild. The owner did say he would rebuild them but couldn't garantee the integrity or performance of the calipers. His reasoning was the caliper was no longer true.
I rebuilt my front calipers a year ago for the same reasons and have had no trouble with them at all. My question is this: Should I rebuild or replace my rear calipers?
I think he suggested replacement because of the liability of workmanship. If the rears failed again it would be the fault of the caliper not the rebuilder.

Thanks,
Ted

[APKhaos]

There are a few situations where replacement of the caliper is indicated, including failed seals between the caliper halves, corrosion [especially in the piston bores], etc. Caliper no longer 'true'? Sounds a little sketchy to my ears - what dimension is purportedly out-of-true, and how was this measured??

If the caliper is sound, then a rebuild is simple and effective. Check the state of the piston, and replace if it is corroded.

Oh, and get a cool brake kit on those front brakes, Ted. Now that you are runninf in Blue, and beginning to 'brake like a man', the heat will become an issue. Congrats on your rapid progress on the track :twisted:

[Marc A]

Blue . . . . . Oh s*&% we're never going to hear the end of this. :roll:

PS: Rebuild the suckers, rears don't take the heat that the fronts do, heed Tony's warning about the piston condition.

[Rick Lee]

Ted, you're not gonna get anywhere until you pull your engine. Then we can figure the problem out. Of course, I'd recommend (at the very least) an upgrade to Boxter calipers.

[Dan M]

Since it is much easier to replace than rebuild, that is the direction most shops will go. And yes, if I owned a shop, I would probably replace too for liability and profitability reasons.

Personally I would rebuild it myself and save your money for other things. Seems odd that it would no longer be "true", whatever that means. I had to replace one caliper due to corrosion and I bought a used one from a junk yard and rebuilt it.

--Dan

[Jase007]

FWIW

The only Porsche calipers that I know whose flex warps rotors or create pad wear issues are the early S alloy calipers. They were great for light weight (less unsprung weight) and increased size but would flex under heavy use.

Even these don't get tossed, just get rebuilt (if overheated the seals) and cool brake kits added.

Two years ago at VIR this happened to us at an HSR race. New rotors, pads and more brake hose cooling solved the problem.


Jase

[BW911]

Gee Ted, I think you should replace with Big Reds all around, get rid of those wheels for some 17s, and maybe drop the engine while you are at it.

:wink:

- Bill W.

[Mackpipes]

I just picked up two rebuild kits from ASG. I guess I'll have to see what condition the pistons and inside of the calipers look like. If they are not rebuildable I will upgrade. First order of business is a brake cooling duct kit.

Hey Bill, got a touch of the Leschanderitis? On that note, Performance products is selling 8 piston calipers with 15" rotors. I wonder if I can get those in ceramic? :shock:

Thanks for all the input,

Ted

[BW911]

Naw Ted, we just want to see you work and spend. You're picking up this track driving so fast we need to do something to slow you down.

:wink:

Bill

[Jazzbass]

Ted is in blue after his 2nd DE? Is that right? Through green is less than one month? Wheeeww.... now I can start my DE career next year in green with nothing to worry about :).

Ted - let me know if want some help rebuilding the calipers - I just did all four on my car and built a few tools to make the job easier.

[Mackpipes]

Chris,
I can use the help. I did my fronts and it seemed pretty straight forward. However, I don't have access to HP air to pop out the pistons. I kind of hope they're trashed so I can justify an upgrade. :D

Ted

[APKhaos]

Ted,
Chris can confirm that stock Carrera brakes seem to work OK :twisted:

[Rick Lee]

Ted, doesn't Bill have a spare set of Carrera calipers now? Rebuild them first and then do the R&R, sell your old ones on eBay or get them painted.

[Jazzbass]

Ted - Give me a call. We can have you calipers rebuilt in an hour or so.

[BW911]

LR is right. I do have a pair. I'd forgotten about them. Let me know if you want them.

- Bill

[cmartin]

Tony's not kidding about stock brakes working like champ. Rahter than spend $$ on a brake upgrades, rebuild your calipers to stock, maybe new rubber lines if you dont know when they were last replaced and use nice pads. I couldnt believe Tony had stock brakes, his car stops like it hits a wall. Awesome feeling!

I dont mean to hijack here, but what's up with cooling? I was reading on pelican where some guys have used 993 deflectors instead of cooling ducts. I can picture the ducts getting ripped off pretty easily on the street. The 993 ducts that attach to the a-arm are flexible and are said to survice driveways and speed bumps. Anyone have experience with this?

[APKhaos]

Just for the record, we did NOT hit that wall :shock:

The 993 deflectors are a good idea. I used the ducting kit, but the deflectors look as if they would achieve significant cooling without the complexity of the ducting arrangement, and are potentially less prone to damage.

One caveat: you MUST install a rotor blocking plate for any cooling arrangement to be functional. You can buy them from OG racing, or fabricate your own. The plate is an annular ring that is bolted to the inner outboard face of the rotor, and closes off the gap between the rotor and the spindle. All air directed into the rotor is then forced into the rotor cooling fins, rather than spilling out the other side. Essential!

[Rick Lee]

Ok, I saw that air deflector work on Marc's car. What's the part number for that kit and where do I get it? It looks to be a better bang for the buck than the ducting.

[Mackpipes]

Tony,
Did you get your kit from OG?

Ted

[APKhaos]

Yep - OG have the full kits, and also sell individual parts.
AJ USA also has the kits & parts - details at http://www.ajusa.com/cgi-bin/pb/list?cat_id=6

[Marc A]

Chris:

I put the 993 air deflectors on my car. They cost 30 bucks for both of them. Mounting hardware 4 bucks at Home Depo.

Not a scientific test, but my Fuchs were burning after the sessions during my first DE. In fact I knocked the satin finish off the fronts :x

I installed the deflectors just prior to August DE and noticed that the phone dials were noticable cooler after the sessions.

Also, and I'm knocking wood here, I am the only one of 3 who hasn't found cracks in my front Zimmerman cast drilled rotors. (Just looked yesterday when the phone dials went back on the car 8) )

[cmartin]

Thanks for the info Marc! I'm going with this as my cooling solution, at least I want to try it out. I figure it has to be better than nothing, and looks pretty straight forward.

[Marc A]

BTW, the reason why they call them deflectors is because thats what they do when you go agricultual . . . . . :oops: