Identifying between 'S' & 'A' Calipers

KillerDynoSoar · 07-25-2005, 07:46 AM

Hey guys, after a search on the forum I need to pose the following question.

Identifying between 'S' & 'A' Calipers.. how can I tell if my 77 ATE calipes are the 'S' or the 'A' types???

Are the piston bores of different measurements?

I was told by a buddy that the SC 'A' calipers are very good for the lighterweight cars and am hoping that these are the calipers that I have. I have just had the calipers refurbed like new and am hoping that they are indeed the later ones.

Any clues to identifying?

KillerDynoSoar · 07-25-2005, 07:48 AM

Quote:

'M' Front & Rear brake calipers are made of Steel and have approximately a 3 inch, center to center, bolt spacing. These were used as front calipers up until early 1975.
'S' Front brake calipers are made of Aluminum and have approx. a 3 1/2 inch, center to center, bolt spacing. These were used on some 911s and all 911 Turbos between 1974 and 1977.
'A' Front brake calipers are made of Steel and have approx. a 3 1/2 inch, center to center, bolt spacing. These were used on many mid-70s 911s and practically all 911SCs. In 1984, the Carrera used a wider version of this caliper - the 'wide A'.

I got that from Pelican parts section but It doesn't id between the S and the A calipers.

jpnovak · 07-25-2005, 07:48 AM

S are aluminum
A are cast steel.

A magnet will lead you to your answer.

KillerDynoSoar · 07-25-2005, 07:50 AM

Quote:

Originally posted by jpnovak
S are aluminum
A are cast steel.

A magnet will lead you to your answer.

DOH!!!!!!

Gosh I am so goofy.. should of thought of that.

slightly embaressed!!

Thanks buddy.. he he.

How dumb am I???

Alan.UK · 07-25-2005, 08:46 AM

The S caliper is also one piece whilst the A caliper is in two halves. You can tell the difference between pre 3.2 and 3.2 by the spacer in the middle. The spacer is not the same front and rear, but I think the rears are 10mm for pre 84 and 16mm for the 3.2.

Alan.UK

Here is a rebuilt wide "A"

andyjboy · 07-25-2005, 09:16 AM

Alam - this is the S caliper - note the embossed 'Ate' name:

KillerDynoSoar · 07-25-2005, 09:23 AM

Wow thanks Alan and Andy.

Hmmn gonna get the magnete out to see what I have. I know that I have ATE on the caliper so I am hoping some 'A' calipers have those aswell.

KillerDynoSoar · 07-26-2005, 12:44 AM

Ahh I had a plesent surprise last night when checking my calipers. Not only are they 2 piece Steel calipers identifying them as 'A' calipers but they have the 10mm spacer!!

This is great which means my 77 has late brakes wide 'A' brakes. I am really pleased with this discovery. I knew my car stopped well

now I have to just bolt up all the new reconned calipers and new hardlines.

Thanks guys.

Alan.UK · 05:03 AM

Andy,

Are those calipers zinc plated? or is that gold anodize?

Thanks

Alan