Rotating Caliper Pistons
 

I received reman calipers from a reputable outfit, but the pistons are not properly rotated to the recommended 20 degree angle. The always succinctly mystical Bentley Manual says to rotate them to the correct position before installing pads. Right! Does anyone know if there is a tool that will grip the inside of the piston to acomplish this? As fas as I know the only other alternative is to remove and reinstall the pistons, which I am unwilling to do. I'm disputing this with the companies involved but I'd like to know if someone just knows how to fix it. :confused:

I think you'll have to remove them, but it's not difficult. Just clamp one piston and blow compressed air through the brake line hole and it pops right out.

der Mond-

I purchased some remanufactured calipers and ended up having to rotate the piston on one of them to get the angle correct. I put the caliper in a vice and used a screwdriver against the end of the half circle ridge on the face of the piston. You can slowly force the piston around into position.

You may be better off returning the caliper. The one caliper I had that needed the piston rotated also didn't have the sealing rings between the two halves and it leaked. I waited too long between purchase and install to return mine so I replaced the seals and it works fine now.

Good luck,
Jim

Are the calipers fresh out of the box? If so, I would try a set of long-nose Vise-Grips ... to rotate the pistons after applying a bit of low-pressure compressed air to the caliper to free up one side a bit while holding the other piston with a 'C-clamp' style pair of Vise-Grips. You only want the piston to move out 1/8" - 1/4" or so. After rotating the piston ... push back in, and do the same thing to the other side.

Good luck!

Sean,
Have you done that without removing the dust seals? I kind of hate to remove them.
Dennis

No, but I don't see why you couldn't do it without removing the seals. It's just a ring that hold them on. But, I would remove them anyway and inspect the cylinders and the pistons just to be safe. It would stink if what you got was a couple of rusty pistons with rusty cylinders. I'm a little suspicious of the rebuild if they put the pistons back incorrectly. Be careful if you do try to move them with metal devices, you don't want to scar the pistons or rupture the dust seals.

As Warren said you should be able to rotate them with a suitable set of pliers. Newly rebuilt caliper pistons should rotate very easily. just push the dust seal down if you need room to grab the piston.

Just be sure not to grab the area of the piston that sits in the cylinder.

I just received a new reman caliper from NU GEON today, and the pistons are oriented correctly.

You can use the compressed air or you can use the hyd system of your car to pop the pistons out just far enough to rotate them to the correct 20 degree orientation.
I recommend a piece of wood between the pistons, so they do not extend out completely. If you use compressed air, they will most likely pop out with enough force to break a finger if one happens to be in the way, so be careful.
With the pistons partially extended I was successful rotating them with a pair of electricians' channel lock type pliars.

Thanks, guys. Each step along the way in Porsche DYI is a live-and-learn proces. Too bad I didn't go with NuGeon in the first place.

You should be able to rotate new/ fresh rebuild calipers w/o removing the seals. ATE used to sell a tool, that mirrored the piston face, meshed w/ the piston it allowed fairly easy rotation.

Solution!
 

The nice young man at CarQuest wants to make it better so he tells me he has "...the best foreign new parts warehouse connection in the nation" and he can get 4 new OEM Ate calipers for between 5 and 6 C's total. You staunch DIY guys will cringe at the difference between that price and the cost of 8 new seals and dust caps, and I'll end up working a second part-time job this winter, but for a meticulous and persnickety German like me it's worth it for the peace of mind. So I'll end up with new calipers, Jurid pads, rotors, bearings, seal races and seals, o-rings and dust caps on my "Gold-Plated Porsche." Remember this next summer because the car may be for sale!!! I'm also replacing the FI manifold seals and insulators, engine compartment fuel lines, sound pad, head temp sensor, thermostat o-ring, breather gasket, temp switch and DME relay. Aside from the new stabilizer bar bushings and drop links, spring plate bushings, Bilstiens, turbo tie rods and ball joints. It'll end up at Euro height. I'm hoping it will feel different... Actually, I'm getting it ready for a road trip across country next year. Been wanting to get some kicks on Route 66.