On Tuesday, January 6, 2015 11:09:21 PM UTC-5, bumper wrote:
EPDM rubber is what you want for DOT 3 compatibility. Look at the
following compatibility list, Dot 3 is under "Brake fluid DOT 3,
glycol type". Viton is NOT recommended.

I have a whole bag of EPDM O-rings that are the correct size for the
Cleveland 300 series brake calipers, as used in most GA Cleveland
brakes with 5606 type mineral based fluid (and as used by Stemme GMBH
w/DOT fluids) . . .

Also note that when using DOT-3 fluid it's important to make sure
they pucks (pistons) in your caliper are anodized - otherwise they
will tend to corrode if there's any water in the system (and sooner
or later there will be, as DOT-3 is hygroscopic).

To check the pucks, use an ohmmeter or continuity tester. If the
pucks are anodized, putting the probes on the surface will show
and open, as the anodize layer is an insulator - bare aluminum
conducts of course.

My understanding is that early Cleveland brakes were not anodized
while those made in the last decade or so are anodized.

Thanks Bumper!
Was there a change to the cylinder liner as well as the pistons?
If one finds an early corroded unit, what to do?
Just hone the cylinder?
Replace un-annodized pistons with new parts from Cleveland?
Thanks again for the education,
Best Regards, Dave