Need to indentify this brake caliper...

[porsche_virus]

Okay guys...this should be a simple one for you brake gurus. I need to order a full set of caliper rebuild kits, but don't know if I have "M", "S", or "A" calipers. This is the front right caliper. The car is a stock '74 911, 2.7 CIS. Hopefully someone can identify the model by this pic:

[Tim Walsh]

is that off the rear or the front?

[JWest]

Looks like an "M". Measure the spacing between the mounting bolt holes - 3" is definitely an "M".

[Glasgow 911SC]

Looks like an 'A' caliper fitted to the fron of 911s from early 70s through to the SC. Carrera used same but with spacer for thicker disks.

[porsche_virus]

Yep...3" between the mounting holes, so I guess it's an "M"! Thanks guys!

[Targa Dude]

Do you have a Magnet handy? go steal one off the Fridge..
if they are magnetic, their "M's" If not their S Calipers.

Jorge (Targa Dude)

[old_skul]

It's an M.

[Guardsred911]

Resurrecting this old post.... trying to identify my front caliper from a 77 911S with CIS. bolts holes are at 3.5 inch centers and it's magnetic. A Type?

[Jonny042]

Gonna say yes. Check out:

https://www.pmbperformance.com/mid-911-brakes.html

[OSC911]

Yep "A" caliper

[NYNick]

While we're talking calipers, my caliper pistons are frozen solid in my M's. I don't have a large air compressor to pressurize them outwards, just a small one.

Any suggestions?

[75 911s]

Small one will work. You have to plug the bleeder hole or any other holes. It doesn't take much at all unless they are completely frozen via rust.

[mepstein]

A grease gun will also work.

[Guardsred911]

Thanks! Will report back....

[Guardsred911]

Here are a few picts after I pulled the caliper apart. The fluid looked terrible. A little corrosion, but nothing emery cloth can't fix.

I also recommend using a board between the calipers when using an air compressor to push the pistons out. the corroded side would have been stuck in there, and the cleaner of the two would have come out easily.

[NYNick]

Originally Posted by Guardsred911

Here are a few picts after I pulled the caliper apart. The fluid looked terrible. A little corrosion, but nothing emery cloth can't fix.

I also recommend using a board between the calipers when using an air compressor to push the pistons out. the corroded side would have been stuck in there, and the cleaner of the two would have come out easily.

You split the caliper? You're a braver man than I. I pray for no leaks after reassembly.

I spent two hours at a friends house today trying to get four pistons out of my 2 rear calipers (1972 T). Each one was more rusted/frozen than the next. We attempted to push them back in further a smidge with a C clamp each time, PB blasted them, and then applied 100+ PSI through a jury rigged brake line to get them to move outwards. Each one took several back and forth processes before finally BANGING/POPPING outward. It was a little scary how powerfully they come out.

It wasn't easy, but we won.

BTW, Centric has ZERO M remans anywhere in the country. Why is that?

(BTW, how did you get your calipers so clean?)

[Jack Stands]

I’ve taken to simply send mine to Eric at PMB as they come back cleaned, rebuilt, and replated in a rapid time. Often he has calipers already ready to send out (with a refundable core charge), or can turn yours around quite quickly.

[Guardsred911]

(BTW, how did you get your calipers so clean?)

Thanks! Brake Cleaner and a brush....

[Guardsred911]

Cleaned and ready to assemble.... parts arriving tomorrow... cleaned using a wire brush, wheel, pick, and #000 steel wool.

[Guardsred911]

Success.... works like a champ.... now, onto the other side...