Brake caliper bores - how do they look? - Page 2

Jajohnsen · 03-05-2018, 06:13 AM

yeah the Porsche seals are not so expensive, but the scrapers are $35 each.

911tracker85 · 03-05-2018, 08:07 AM

understand those cheap rebuild kits probably only have dust boots, not scraper rings. not the same. learned that on my 951 when I found some size piston scraper ring NLA for it.

wish I took good pics, but I modified the dust boot to work on the caliper piston where I ruined the scraper rings prying them out. only destroyed that one, then left the scraper rings in place and only replaced the seals on all the others.

a little complicated to explain. but as commented it only keeps dirt out, and I pull/check all my brakes between every DE event. got the 951 in the shop now for the full spring track prep.

good luck.

turbo owner · turbo owner's Garage

Quote:

Originally Posted by 911tracker85

understand those cheap rebuild kits probably only have dust boots, not scraper rings. not the same. learned that on my 951 when I found some size piston scraper ring NLA for it.

wish I took good pics, but I modified the dust boot to work on the caliper piston where I ruined the scraper rings prying them out. only destroyed that one, then left the scraper rings in place and only replaced the seals on all the others.

a little complicated to explain. but as commented it only keeps dirt out, and I pull/check all my brakes between every DE event. got the 951 in the shop now for the full spring track prep.

good luck.

The URO scraper rings look just like the Porsche ones for the 930 calipers, the place in China probably make all of them.

Jajohnsen · 08:51 AM

Ordered a sett so will compare when i get them. It says that it comes complete with scraper rings and seals. And lists the equivalent porsche partnummbers.

https://www.uroparts.com/uro/inventory/show/8867

Chinook · Chinook's Garage

Your photos #2 & #3 showing the grooves are pretty edgy to me. If/ when the calipers are completely cleaned and it is clear that the corrosion pitting has compromised some of the three surfaces (especially the bottom ) of the primary seal groove MOVE ON TO NEW OR BETTER CALIPERS!

Brakes are not something to compromise over especially with these cars that can generate (and usually do) triple digit speeds.
You and all are worth the money spent for excellent brakes for C..... sake. No messing around in this area.
If you are still unsure then take the calipers to a local expert for verification.

Again, you and that lovely lady in the 1st officer's seat are worth it!
Gman

Jajohnsen · 03-06-2018, 12:25 AM

Gman, could not agree more that brakes should be 100%. That's why I startet this thread to get help and opinions from all the great people here

I'm getting a smal dentists mirror so I can inspect all the surfaces of the groves, and also trying to make a small adapter for my sodablaster to get a better "blast" in the grove.

So if any of the surfaces on the grove is compromised the recommendation is to move on to new calipers, or at least get them verified by a local brake shop.

911tracker85 · 03-06-2018, 06:26 AM

what was the price from URO? cant figure out how to find that.

your link shows a set for the front, do they also have rear?

I'll have to check them to see if they also have scraper rings for the 951.

Jajohnsen · 03-06-2018, 06:43 AM

yes, they have the same sett for rears. https://www.uroparts.com/uro/inventory/show/8868

I payed $31 each. Was on sale yeasterday, now it seems to be $47.

google PO-930RBCKIT and you should fine some prices

automobile · 12-02-2020, 03:09 AM

Perhaps someone can advise ;

Got some new pistons for calipers to replace a few pitted ones;

Front 38mm is genuine Porsche & has really smooth anodised finish as per original.

Rear 30mm are retroline reproduction . The black finish is not as smooth as the genuine one , suspect it's not anodising ,but some other coating ?

My concern is that they wont seal properly & also will wear the new bore rubber seals due to slight roughness on piston.

Any opinions ?

stownsen914 · 12-05-2020, 03:56 AM

I am rebuilding some 930 calipers and also considered replacing a couple pistons. I ordered replacements and was not impressed with the finish. Mine were similar to what you describe for the rear pistons you bought. Definitely worse than what I was looking to replace. I returned it and just cleaned mine up with crocus cloth.