Front caliper upgrade for Type 3's.

[KTPhil]

I'll dig out my Elfrink Type 3 book, which gives a little more info about this compensation pin than Bentley. The latter implies the pin is still in later calipers. Stay tuned...

[raygreenwood]

[KTPhil]

Ok, here we go. First up, Bentley:

Note the quote near the bottom of the right column:
"Each piston is hollow and contains a brake disc deflection compensator. The cylindrical pin for the compensator is permanently fixed in the cylinder end in each caliper housing."

Oddly, though this next page is an exploded view of the early, single-bleeder design, it lacks the pin; perhaps this was a pre-production rendering? Possible, since it has the bleeder mis-located as well.

Next comes the British Autobooks page, whose exploded diagram DOES include the pin:; this is also an early caliper with the single bleeder.

Lastly, here is Elfrink's complete description of the system and theory of operation:

The text implies it was not just the disc that distorted, but the spindle as well, plus loose wheel bearings.

And the final Elfrink page gives the part numbers for the later dual-bleeder design.

There is no mention of deleting the compensation pin design. This could be oversight, but perhaps from the factory they had it, and replacement calipers did not?

Did the bearings change at this time to reduce this problem?

There is no mention of a new piston part number, though if the pin was deleted certainly all that jazz inside the piston would have been deleted, too. But maybe the piston is considered part of the caliper assembly, and therefore could be different? Did VW supply pistons as a replacement part, or just the whole caliper assemblies?

It is also possible Elfrink's appendix for the late design was for an "early late" design and not a "late late" design which may have deleted the compensator?

I find it odd that VW (well, actually probably ATE) chose this complex solution when merely thickening the disc and/or spindle castings, as done later, would have almost certainly been cheaper, and more effective and reliable.

We are closer to a perfect history, but not quite there!

[raygreenwood]

Yes..... ...that is a mis-rendering in the Bentley! Notice the piston in teh airbrushed rendering....with the raised dimple in the middle....that is only used on pistons that have pns.

Also...notice that all of the rotors in all of those pictures....have no centering ring. They are all earlier than August of 1972...meaning they probably all had pins. The Elfrink manuals were excellent....but you will probably find that they are too early to know what VW changed in August of 1972. Ray

[VWporscheGT3]

https://www.jbugs.com/product/16-2526-0.html?rrec=true

dont forget , these are an option now. but unfortunately I havent been able to find specs on the size of the pistons yet, unless Im blind, and I havent gotten off my ass to call wilwood yet.
_________________
If you have any questions about Forged ICON 4032 VW pistons just shoot me a line.

[Bobnotch]

I find it odd, that it's been mentioned that the late rotor is thicker (11mm), but when purchasing new earlier style rotors, they are 11mm new.
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Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120

[KTPhil]

Elfrink lists the early discs as 9.5mm, with a wear limit of 8.5mm.
Elfrink lists the late discs as 11mm, with a wear limit of 9.5mm

However, the Autoboooks spec for discs (presumably early) is 9.5 to 9.45mm, with a minimum of 8mm. Ballsy, those Brits!

Bentley agree with the thinner 8mm wear limit on page 2-21, but then lists 8.5mm on page 2-24 when machining, though the same paragraph says replace if under 8mm!

Confused?

[Tvättbjörn]

[Tvättbjörn]

How many different disc spindles made VW ?

The Type3 spindle did change 8/71 from the small bolt pattern to the larger pattern.

Did the 73 model have the same spindles like the 72 or was it different again?

[leoasman]

If I wanted just new stock style calipers and rotors for a 68, where do you guys recommend shopping online? I’ve checked several sites, but it gets confusing for me with all of the conversion sets and manufacturers.

Thanks,
Leo

[pitargue]

[leoasman]

[bassam]

In my country where it was impossible to find the replacement caliper, I went for 1978-1983 320i caliper (with 2 bleeders not 1) and they were a perfect fit, no machining needed. Thank you for this thread, it was a life savior.
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1973 VW Squareback

[pitargue]

[raygreenwood]

For the late model type 3 caliper....which is the same as early 411/412/914......PMB performance will FULLY rebuild yours. This includes ALL seals including cal8per half seals, hardware, stripping and replating to favtory zinc.

They are probably the vsry best in the business.....short of my own rebuilds.....

Ray

[veedweeb]

[VWporscheGT3]

Just because I have been doing a lot of research into this... i thought i would share. and please anyone who knows better please let me know where i am wrong.

if you have 72-73 spindles , than this wilwood kit becomes an option.

https://wilwood.com/BrakeKits/BrakeKitsProdFront?i...p;option=4

since the late calipers run the same spacing as the 914's, type 3 rotors use the same wheel bearings , and such... this becomes a bolt in modification. you gain vented rotors with traditional 4 lug pattern (if you care to retain 4 lug) with 4 pot calipers braided lines etc... as with everything they are pricey , but in some cases , cheaper than other options out there.

unfortunately since 914 rear arms have their caliper mounts integrated to the arm.. the rear kits isnt bolt in .

this all being said... who has a pair of 73 spindles they wanna sell me? lol
_________________
If you have any questions about Forged ICON 4032 VW pistons just shoot me a line.