What is the best way to judge the 20 degree angle on a caliper rebuild

[porschzilla]

Hi All,

I hope to start rebuilding all 4 calipers this week. I know that it is necessary to have a 20 degree tilt on the caliper. How have you done it? Have you made tools? What did you use to measure the 20 degree angle? A protractor?

Thanks
Jack

[Zeke]

There are a lot better answers, but if you can "see" the centerline of the rotor as the caliper sits bolted, 20* is simply the right angle to the radial as it intersects the pad. You can make a cardboard template.

Now, for the better answer, I give you.....

[getluky]

Yeah, I took a protractor, drew a 20deg angle on a piece of carboard from a cereal box, and cut it out. Pretty cheesy, but it worked!

[sailchef]

I used a cardboard cutout. The diagram is in the Tech Articles under caliper rebuild. If I remember You need to be looking at it from the right direction or it gets backwards.

getlucky beat me to it.

[Eric_Shea]

It's fairly easy actually.

Draw an imaginary line down the center of the pad cavity. Place the lower notch on the piston on this line. Have the cutout facing the direction of the oncoming rotor.

[aigel]

You can eyeball this. If you are 15 or 25 degrees it will still work. I had used a protractor to look at how 20 degrees looks like and then just went ahead and eyeballed it.

Cheers,

George

[Neilk]

Check out this thread

[Flieger]

I like Eric's technique. I would definately not just "eyeball it" when it is so easy to get a 20* piece of cardboard- or Aluminum with a protractor.

[scottrx7tt]

i would just buy a remanufactured one from ********. I got mine for $42 a piece.

[Gunter]

Originally Posted by scottrx7tt

i would just buy a remanufactured one from ********. I got mine for $42 a piece.

O.K. for exchanges but, I would still check the 20 deg because I've seen it screwed up on rebuilds.

Try and set the 20 deg before you insert the piston because it's very hard to turn them once they're in.
And make sure that the off-set is in the right position.

Some people don't believe it but this old ME knows that the off-set is essential for the pads to function at maximum efficiency.

[tomphot]

I have piece of 26 ga sheet metal from Home Depot - $4 - marked it for 20% and then cut it out with tin snips to look like what is shown in the directions. Took 5 minutes - i also like the way it fits when your checking the fit - much better than just using cardboard.

[ruf-porsche]

Originally Posted by Gunter

O.K. for exchanges but, I would still check the 20 deg because I've seen it screwed up on rebuilds.

Try and set the 20 deg before you insert the piston because it's very hard to turn them once they're in.
And make sure that the off-set is in the right position.

Some people don't believe it but this old ME knows that the off-set is essential for the pads to function at maximum efficiency.

My understanding for the 20 degreed setup are so that the brake pads will not squeak or squeal as much. It has nothing to do with maximum efficency.

The calipers on my Lotus cars do not have a 20 degreed requirements and are similar in design to the SC caliper. They use two pistons per caliper to push the pads against the rotor, and are not floating calipers as used in most of the cars these days.

When I went to rebuild my SC Caliper lasy year, I just eyeballed the 20 degreed. The brake works as well as before so I guess the eyeball method was good enough.

[Zeke]

Don't forget to "ease" or chamfer the leading edge of the brake pad to stop squealing.

[Eric_Shea]

Originally Posted by milt

Don't forget to "ease" or chamfer the leading edge of the brake pad to stop squealing.

That's what the step on the piston is supposed to resolve. ATE built them this was so you wouldn't have to do that.