When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
FYI you can step up to big blacks for a lot less than $1600. Sunset is where I bought the calipers for around $260 a side then you need adapters $150 and depending on what rotor you go with, ~$450
Evidently you haven't done the math..... $300+ minimum for parts. Those calipers are worth that much considering you can find the later calipers typically prices similarly and the minimum parts cost is more like $32
Originally Posted by autokurl
Oddjob, what it appears you are not getting is that to rebuilt the caliper you need new scrapper rings.
The only thing I am not getting is how you are rebuilding late calipers for only $32? Seals alone are over $120 per caliper pair (same as for the early calipers). For full piston kits, its close to $150-230 per axle pair, depending on front, rear or 928S4.
Ooops. My bad. In re-reading the thread it appears I started to compare apples and oranges. To simply replace the dust boots would be $40 minimum. Where did I get that #? The StopTech Dust boots are only $4.95 ea and you need 8. $4.95 x 8 = $39.60.
But that wasn't for a full rebuild. I was simply comparing the absolute minimum cost to replace the dust boots/scrapper rings. With the scrapper ring calipers the absolute minimum was about $300 vs. $40 for the dust boot style.
And for that matter a full rebuild (seals and dust boots/scrapper rings) is still heavily biased toward the newer style calipers. I just checked my StopTech price list. Seals are $7.95 ea and dust boots are $4.95 ea. You will need 8 of each.... Total comes to $103.20
This is why, IMO, the scrapper ring calipers are worth it even if they are free! $300+ to rebuild vs. $100 to rebuild the dust boot style.
I went through this, Jim. Half the stuff in the stoptech bags I couldn't use, but it was cheaper to use the piston seals and put the dust boots in a museum. I think the late calipers are machined to accept the larger diameter dust boots, and ours are flush right up to the piston bore. Either way, early guys have been warned that scrapers are $$$. I used care with the scrapers, and replaced the piston seals.
I'd consider an early set of calipers with boogered scrapers "totalled".
With the age of the scrapper ring calipers the scrapper ring should be replaced with a rebuild. Not replacing the scrapper ring, which is basically a rubber seal sitting in a metal outer ring, is to invite road crud into the piston bores which will eventually create a leak. Trust me on this. I speak from experience....
Interesting. I've never seen, nor heard of a scraper ring failing. I know lots of racers who rebuild brakes every year or two and have never had to replace a scraper ring. I wonder if your experience might have been a one-off? My whole brake system had crud in it from the car sitting for a few years, and I've not had any issues. I've got a few brand new scraper rings sitting in a drawer because I had to replace pistons (like scrapers, only sold in the kits), and wasn't going to mess with the scraper rings.
One thing I would say for anyone doing a rebuild. Through four sets of rebuilt brakes, I've seen pretty consistent results. Stop Tech seals are harder to deal with than Brembo seals, in that it is much harder to get the piston back in, and you are more prone to shearing a seal. It helps if you take a pick with a 90 degree bend on it, and kind of "lift" the bottom of the seal off of the ring bore. Stop Tech seems to be the preferred supplier for race teams, given anecdotal experience, as well as what the ones that resell stuff sell. Brembos are definately easier to install, though. Keep in mind a few pounds of pressure to install is inconsequential compared to the thousands of pounds of pressure under operation.
I've used Racers Edge to get my (Stop Tech) seals and dust boots for the later style calipers. The (Brembo) whole piston kit is available from Porsche.
The Brembo parts are available from a large number of retailers: Hoerr Racing Products, Pro-System, Paragon Products, Racer's Edge, Zechausen, just to name a few. They will be more expensive than the StopTech parts. Typically the Brembo parts are double the price of the StopTech parts. Brembo also has a new design seal they refer to as a "Anti Knock Back" design. I have no specific experience with the new design seals and therefore can't comment on them. I've never had any issue with the StopTech parts other than to say the "bellows" area (the area of the dust boot that does the flexing/extending) of the dust boot seems to be thinner and subsequently less durable than the the Brembo. Over the years I have probably rebuild/refinish a couple hundred calipers. As to the StopTech seals, measure them. They do come out to be the exact same size as the Brembo. They even have the same color coding. If you are/were having an issue getting the pistons back into the bore there may be something else going on.
The Brembo parts are available from a large number of retailers: Hoerr Racing Products, Pro-System, Paragon Products, Racer's Edge, Zechausen, just to name a few. They will be more expensive than the StopTech parts. Typically the Brembo parts are double the price of the StopTech parts. Brembo also has a new design seal they refer to as a "Anti Knock Back" design. I have no specific experience with the new design seals and therefore can't comment on them. I've never had any issue with the StopTech parts other than to say the "bellows" area (the area of the dust boot that does the flexing/extending) of the dust boot seems to be thinner and subsequently less durable than the the Brembo. Over the years I have probably rebuild/refinish a couple hundred calipers. As to the StopTech seals, measure them. They do come out to be the exact same size as the Brembo. They even have the same color coding. If you are/were having an issue getting the pistons back into the bore there may be something else going on.
Michael
My experience is different than yours. I have done some engineering work with one of the vendor's you list up there, and will be starting there on a more permanent basis in about a week. While there are a few old Brembo seals laying around, they are an authorized vendor for, and sell exclusively Stop Tech, and use them on their race cars. From the stuff we have laying around, we can tell them apart by the lack of paint on the Stop Tech seals.
I have some stufff laying around for one of my car. Here are some pictures that show the lack of paint, and the difference in thicknesses. Stop Tech is on the left with no paint, Brembo on the right with paint. They are laid on top of their respective packaging. There are also threads on this forum where many people have had significantly different experiences with the seals, if anyone wants to do a search.
OK, I stand corrected. That's very good information. Admittedly I haven't done anything real recently and ever since Cresenti/Centric took over StopTech things have changed..... It would appear the Brembo parts, while being twice the price, are really the way to go now.
OK, I stand corrected. That's very good information. Admittedly I haven't done anything real recently and ever since Cresenti/Centric took over StopTech things have changed..... It would appear the Brembo parts, while being twice the price, are really the way to go now.
Also PM sent.
Michael
Just saying that is what I have seen - there's rarely a "right" or "wrong." I've had plenty of people tell me they've not had any issues with the Stop Tech parts, as well as those who have. Another interesting twist to this is that the Stop Tech seals in teh scraper style calipers, from my experience, were very difficult, but in the boot style, only marginally difficult. It actually came up at lunch from something we were messing with Friday and again, the race cars all get Stop Techs, and they've never been an issue (though they all have boot style ones).
And while I find that the Brembos are "easier" to deal with, but I personally don't think that makes them "the right way to go." Just my take, there are certainly people who disagree with me on that. The Stop Techs just take more patience.
Just pumping this old thread because I have just gone through the process of trying to figure out what parts I needed and it’s quite confusing. I ordered what I thought were the correct parts from Zeckhausen, Then just because I was unsure I broke the calipers down and measured the pistons and to my surprise I was completely wrong they were actually a set of rear calipers and I had been told that they were front calipers placed on the rear of the car. Because this is a 944LS3 conversion. David Zeckhausen was very helpful and had me measure the length of the pistons
Of which I needed 2 new 28 mm pistons. Apparently they come in 29.5 and 32 mm lengths. FYI mine were 32mm.
If you look at the piston in the picture you can see two tiny little nicks on the surface that’s why I’m replacing that one So
All’s well that ends well
TSB document describing a production change on the 944 Turbos, from "early" to "late" style. Looks like it answers my question. The caliper body itself is different, to accommodate the dust boot. Damn.
10-22-2011, 02:14 PM
