early calipers rear

[atk133]

Hello all,

First post here, from a short term lurker.

The rear calipers on my '67 912 are seeping fluid out of the bleed nipples. These are the small calipers that I don't find rebuilds listed for in any of the catalogs I have.

I replaced the worn nipples, which slowed the seepage somewhat, but I'm guessing that the nipple seats are just too far gone. I see a couple of options, and am hoping someone here can give me guidance.

I've read that a machine shop should be able to machine new seats into the caliper or I could scrounge for a used set and rebuild them hoping that the seats are still good, or find a way to fit the '69 - rear "M" calipers ( I assume the bolt pattern is different, becasue it would be way too easy if it was the same ).

So, if anyone can recommend something, it would really make my week.

Thanks,
Dave A

[Bill Verburg]

You have 'L' calipers the bolt spacing is the same as the 'M' caliper but it is designed for a thinner non vented rotor. If you can't satisfactorily repair/replace what you have get 'M's to replace with the thicker vented rotor, they should be cheap and plentiful with all the brake upgrades being done.

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Bill Verburg
My Home Page My Pelican Gallery page My Porsche Owners Gallery Page


[This message has been edited by Bill Verburg (edited 08-23-2001).]

[Early_S_Man]

Dave,

Both rear calipers have this SAME PROBLEM?

Did you clean out the threaded recess for the nipples before replacing them? Were the nipples you installed new or used? It almost sounds like you put in the wrong length (too short) bleeder from a VW wheel cylinder or something!

I have bever even heard of a leaking bleeder nipple! Were you using the proper-sized 6-point box-end wrench to tighten them?

The mounting ears on the 'L' calipers are more narrow than the 'M' calipers, but not by much, perhaps 10 mm. A good welding shop should be able to add a piece of structural steel bar material to your hub carrier to widen the ears, if you choose to change to the 'M' calipers.

If you check with a local parts store carrying the Raybestos brand, they will be able to order rebuild kits that have genuine blue Ate boxes inside the Raybestos box for any German car. I believe you have 35 mm pistons inside those 'L' calipers. But, you probably should clean the old caliper and inspect the pistons for pitting before ordering a rebuild kit!
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Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[This message has been edited by Early_S_Man (edited 08-23-2001).]

[atk133]

Oh man,

This morning I typed in a big long post with more info and thanks to you guys for helping, and now its not showing up.

I'll just re-do the relevant parts: So, in order to use the M calipers on the rear, I will need an intermediate plate which will move the caliper out to where the L caliper was oriented. And then I will need to get thicker rotors because the caliper halves are wider spaced on the M's. Did I get this right? I should be able to use solid rotors from a '69 - as long as they are thicker than my -'68 rotors?

And the other part was thanking you guys for hooking on to this thread, and saying that I was in tune to everything that was being said.

Oh, and yes, all 4 of the possible nipple locations had leaked, just at different times, with the old rounded nipples. I used Russell speed bleeders after that, and the major streams have turned into minor damp patches, but the resulting air bubbles are still present.

Dave A
'67 912 #72