C3 Disc brake pads

[Jeffrey S.]

Hello All. I have several sets of disc pads and would like to know if anyone can tell me if they are semi-metallic, organic, or? Two of the sets are in Kelsey Hayes boxes, part #79218. They have "W.Delco-601-FF WDE" imprinted on the edge of the pads. The other sets are not in boxes and have "A.B.I FE" imprinted on the edge of the pads. I know it's a long shot but if anyone can recognise the numbers it would be great. I'm hoping that either of them are organic and I can use them on my '69. Thanks all.
Jeff

[John H.]

Re: C3 Disc brake pads

Jeff -

I don't know the exact correlation between the D.O.T. "Edge Code" and the pad material (if there is any), but the 2-letter code indicates the coefficient of friction at 250*F and at 600*F. "EE" is the base code (0.25 to 0.35 at both temps), FE is the next higher (0.25-0.35 @ 250*F, 0.35-0.45 @ 600*F), and FF is the next highest (0.35-0.45 at both temps). GG is very rare (0.45-0.55 at both temps - "race" pads), and HH is 0.55-0.65 at 3000*F (glowing) - these are carbon pads for carbon discs (Formula 1 stuff).

I'd suspect the "EE" pads are organic, but I don't know for sure.

[Duke W.]

Try a magnet

Most "metallic" brake friction materials have iron in them, so they should be magnetic, although I have seen "organic" pads that have copper filaments for heat transfer.

Place the magnet on the center of the friction material. Then try the backing plate side with some pieces of cardboard or other non-magnetic material as spacers about the thickness of the friction material to see if there is any difference in attraction.

I know that the J-65 drum brake friction material is magnetic. If the friction material is magetic a typical mechanic's magnet for retrieving parts should lift the pad, but not from the backing plate side with cardboard spacers about the thickness of the friction material, which is probably about 1/2" or a little less.

Duke

[Jeffrey S.]

Re: Try a magnet

John & Duke:
Thanks for your responses I put a magnet on both sets and 1 had a very slight pull and the other had no pull at all so my guess is that this set is organic. I have read on this board that to finally get rid of any brake squeel I should use these and champher the ends of the braking material at a 45 degree angle as per the TSB. Thanks for your help.
Jeff