rear calipers

[chumpf]

anybody know if there is any difference between rear calipers with two bleeder screws and the ones with only one bleeder

mine only have one and there are calipers on e-bay with two bleeders

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33563&item=2419366865

(im not actually gonna buy these, im gonna rebuild my own)


are the two different styles interchangable
im guessing the two bleeder is late model and one bleeder is early models


Austin

[kellzey]

Porsche changed at some point. I don't think there is a difference other than the extra port. If you install them, make sure the bleed port (valve) is on the top so the air can escape.

Regards,

Karl

[philinjax]

The 914-6 cars have one bleeder valve per rear caliper, all 914-4 cars have two bleeder valves per rear caliper.

Phil

[kellzey]

Phil would know.. he has lots of cars and parts!

Nice fellow!

[Dave at Pelican Parts]

I don't think that is correct. I believe that the early -4 rears have one bleeder, and the late ones have two. I think that is the only difference between early and late four-cylinder rear brakes, though.

The -6 brakes have different diameter pistons in the caliper, though I don't remember the exact numbers.

--DD

[philinjax]

There is no doubt that the 914-6 rear calipers differ from the 914-4 rear calipers, the question has to do with the number of bleed valves. All 914-4s have 2 bleed valves per caliper.
Phil

[romoman]

I have a 72 1.7 that only has 1 bleeder per caliper. In fact, I've never seen any with 2!

[74914]

They're interchangable, but the guts are different. This will only come into play if you need to scrounge for replacement pistons (pitted), adjuster screws (broked teeth on inner screw), or caliper halves (bad bores). The 2-bleed calipers use 10mm inner and outer adjuster screws and pistons, while the 1 bleed use 8mm. Also the 2-bleed uses hex bolts to connect the caliper halves, with a tapped outer caliper half, while the 1-bleed uses T27 Torx bolts, countersunk into the outer caliper half, with a nut on the inner half.
Not sure which is early or late...my '70 and '74 came with both types.
Ed

[philinjax]

Ack!!! I just checked my stock of rear calipers, found both one and two bleed valve types. Goes to show you what I know. My dumbass self assurance got the best of me. Sorry guys.
Phil

[chumpf]

Thanks for the response guys,

just wanted to make sure that the calipers were interchangeable in case i mine cant be rebuilt.


Austin

[914nate73]

I'm not sure of any difference but I can tell you from experience, kids do not try this at home, I have done a quik replacement of calipers, and wanted to check if the pistons were working and only bled the top screw and they seemed to stop almost as good as when I later bled the bottom. Of couse you would never really do such a stupid bleed job and drive on them, but this was just a, round the block type thing. I just found it interesting how small the effect was only bleeding the top. Does'nt answer your question but leads me to think that one bleeder screw or two should'nt make a difference but, what do I know.
Nate