Cleaning/Rebuilding 930 Calipers....

[douglas bray]

Just acquired a full set of 930 brakes and the calipers need a bit of clean up. Is anyone opposed to my usual Simple Green and a plastic bristle scrub brush routine? I've never had such insane brakes....and I don't think paint is needed. Hardware is perfect. Thinking I just need to scrub off the grease and send the rears off to have the mounts machined to fit.

THEY ARE MASSIVE.

Rears:



Fronts are still on the donor car.

[douglas bray]

So, y'all are keepin' the hot tip a secret?

Simple Green alone did nothing. I've resorted to a hot water bubble bath and it seem to be well on it's way to cutting it. Yes, the inlets are plugged. Thinking the next step is the pressure washer.

[theclaw]

You are going to rebuild them right? What about bead blasting and refinishing?

[douglas bray]

Originally Posted by theclaw

You are going to rebuild them right? What about bead blasting and refinishing?

Well....Yes, but not until the rears are back from milling the new mounting holes. I just want them clean while they are on the bench. The last thing I want to do is harm the paint. They practically look NOS. They even had the OEM pads in them. No way am I going to blast and paint them.

[douglas bray]

LOL. Thank you Bill for the awesome post in this thread. Where was it a couple hours ago?

Cleaning 930 calipers (early 917 calipers) AND floating 930 rotors? + QUESTIONS

[douglas bray]

Now they are worthy of my bench. And yes, the anodizing does look very faded and thin now that the oils are out of it.

[m110]

After going through the cost of obtaining these and the trouble of machining the rears ( I assume you have a SC or Carrera) I would seriously consider rebuilding the pistons and seals unless they are pristine. For me that would be PMB.

[douglas bray]

Originally Posted by m110

After going through the cost of obtaining these and the trouble of machining the rears ( I assume you have a SC or Carrera) I would seriously consider rebuilding the pistons and seals unless they are pristine. For me that would be PMB.

They are going on my '88. Thinking they are pristine, but still want to dig into them. Looks like I am going to have to make some sort of jig to mount them to my vice so I can brake the bolts loose on them. Or...mouth them to the new struts and sit on them. LOL.

There is a noticeable difference in the finish on the bolts that were on the inward sides of the calipers. Inside bolts were still bright yellow, outsides were faded. Likely sun exposure and cleaning. Still stoaked.

[KTL]

I suspect the anodizing is cloudy from years of harsh wheel cleaners.

But why disassemble the calipers? There's no benefit to doing that IMO, other than putting new bolts in them. There's high potential of stripping the aluminum receiving threads. Believe me, years of heat, brake dust, moisture can make loosening the bolts a REAL challenge. Been there done that on other Porsche Brembo 4 piston alloy calipers where it takes quite a bit of heat, a sturdily mounted vise and more leverage than you feel comfortable applying to your nice calipers. Mine weren't all that nice- cheap (free) 964 rears I was saving from donation to scrap metal & adapting them to fit 930 rotors. Also when you split them you are often going to be sacrificing the crossover tubes that don't want to come loose.

I do recognize the rears must be disassembled to machine them accordingly to fit your Carrera trailing arms. I would let whoever is doing the machining disassemble them.

You can rebuild them piston-wise as assembled. Pistons pop out easily with compressed air, some ingenuity to capture the other three pistons & caution/padding. Assuming the pistons are in good shape, which they typically are since they are hard anodized, all you need are new pressure seals and scraper seals. Centric has good pressure seals and dust/scraper seals.

What rotors are you going to use in front? Rear rotors are a no-brainer with the '78-'89 OEM Zimmerman 930 rotor being a perfect fit.

[douglas bray]

Keven, nice tip on letting the machine shop worry about taking them apart the first time.. At this point it was simple vanity that got me thinking about swapping the bolts side to side. The crossover tubes came right off when I cleaned them. They look brand new. Went back together like any other brake line. Anodizing looks to have rubbed thin, not gotten cloudy.

I currently have drilled and coated Zimmermann's on the front and back and love them. Had them a couple years and they still look like I have not installed them.

(Current calipers and rotors will be going up for sale)

Going with Sebro. Hope this is real at $170.31

EDIT: Looks like our host blocks ad-links. Let's just say that they can be found online.

To my uneducated eye that one looks a lot like this one at $353.75

Porsche 911 (1974-1989) - Brake Pads & Rotors - Page 4

[KTL]

Sebro is a good rotor. They are OEM for many Audi & Mercedes applications. Maybe even some newer Porsche stuff i'm unaware of.

If you get the $353 style rotor then you need to get hats and floater hardware to mount them. True floating rotors are NOISY for a street car. VCI has their own solution to the no longer available OEM Porsche floating hats & hardware at the very bottom of this page VCI - Porsche 911- 930 69-89, 914/6 brake upgrade page. But all told when done you would be paying $1000 alone for just the front rotors & hats + hardware. That's seriously expensive, especially for a street car, and all that's really afforded you is a needlessly noisy racing rotor assembly to enjoy

Clint at Rebel Racing has a better 930 rotor solution IMO brake system components Rebel S Racing Products Or you could take it a step further and use Clint's 8 hole hats and mount them to a Wilwood HD 40 rotor like I did for my racecar Wilwood High-Performance Disc Brakes - Rotor No: 160-3846 The Wilwoods are directional just like 930 rotors so you need a left and a right (160-3846, 160-3847). In my experience of using them for ~10 yrs is they are a good quality rotor that is also reasonably priced. If they can withstand racing use, they're certainly up to the task for a 930 street brake setup. Or if you want a little bit of racing look to play off of the drilled 930 rear rotors, you could use the Wilwood GT 48 slotted rotor Wilwood High-Performance Disc Brakes - Rotor No: 160-11837

[douglas bray]

Looks like if pulled the trigger today Rebel would get the majority of the business. Hats, machine work, and master cylinder.

I've listed after drilled rotors for 40 years so nobody is talking me out of them now.

One big blow to my build just came in the form of out of stock G50 Tbars. Steve Weiner was given the assignment of supplying me with 28mm Sanders. Sanders is now saying January at the earliest. Chuck Moreland can't even help. I even struck out in the used stacks at Einmalig. If I want to start this build anytime soon I'm going to have to find a good used set somewhere. .....or someone is going to have to help me navigate the catalog here and know that I'm not going to trust Sway-A-Way with a G50 tub.

[KTL]

Ok just thought the front rotors could be simplified by avoiding the expensive and noisy OEM-style floaters.

Are 29mm bars available. I used 22/29 on my '87 and the combo worked very nicely. Not too harsh and the balance was excellent (tested on the track) for all around use.

Sway A Way makes good quality bars. They've been in the biz for a long time and their bars are good. Not as pretty as Sander, but certainly up to the task.

[douglas bray]

Made a bit of a jig tonight and took the calipers apart. The dogs and seals look fantastic now that I've got the dust off them. The bolts had copper anti-cease on them and of course, I could not find my tube of it in my shed. Ended up at O'Reilly where they had 1,400 deg. silver, 1,800 deg. copper, and 2,000 deg. copper...I went with 2,000 deg. copper.



Did I mention that everything looks good?

[Ronnie's.930]

Doug, just curious - you said you were no way going to paint them, but wanted to switch the bolts out of vanity because the ones on the inside look better, however, the black finish on them looks terrible (at least in the pics). You're really not going to refinish then now that you've had them apart? No offence - just thinking from my own perspective (aka: I would refinish them without question).

And yep, they are massive, considering how small 911s & 930s are, and their stopping power is very impressive. My friends always kid me about how I've got more brake in one caliper than than they have on all four wheels combined.

[Craig_D]

I would send those to Eric at PMB in a NY minute. All he does is brakes. Loves them, makes them better than new. That's my experience, and I would do 930 brakes right. Just my two cents.

[douglas bray]

Guessing it's time to Google PMB.

In person they look great. I did pick up four fresh bolts today at Einmalig to swap out the ones I wasn't happy with. You guys will come around once they are all together....No??? Remember you are looking at crappy Droid pictures I've shrunk with an old version of Paint.

Chomping at the bit to pull the fronts off the donor car and start on them.

[Craig_D]

Eric Shea is your man. PMB Performance: We Don't Rebuild Your Brakes... We Restore Them


930 brake restoration: 930 Front Caliper Restoration

You'll realize how bad they really looked, when you get them back from Eric, trust us.

[douglas bray]

You guys don't seriously think I'm going to spend $1,400+shipping for calipers I bartered for? Lordy Lordy it's a freakin' Porsche, not a B2 Spirit.

930 Rear Caliper Restoration

[douglas bray]

Ya, there is no effing way I'm paying someone to make them look like their pictures. Mine look better than theirs. Their bolts look chromed and I'll just stop right there....for all I know one of you is sleeping with the dude.