Difference between early and late rear brakes Options

[wbgoggans]

I have a very late 72 4722919061. I unfortunately ordered the early brakes from pmb performance. However after speaking with them on the phone and placing washer between the inside of the Caliper and the caliper bolt I have managed to make one side fit. However on the passenger side the top of the caliper is rubbing on the rotor. I will include pictures to better illustrate. My question is what is the difference between the early and late calipers on the rear that keeps them from being interchangeable? Is there anything I can to make them fit?

[wbgoggans]

The passenger side. Note the washer and plenty of room between the rotor and caliper.

[Tbrown4x4]

Hmm. I didn't think there was a difference on the rear calipers. My DD is a '73 and my parts car is a '71. I rebuilt the early calipers and swapped them out with the lates so I wouldn't have any down time. I thought the only difference was the early calipers have RIBE head through-bolts holding the calipers together, and two bleed screws.

Interested to see how the more experienced members answer this.

Are the rotors the same? Are there any spacers?

[914Sixer]

All the rears should be the same except for late has 2 bleeder valves.

[bbrock]

My mid-73 had one early and one late rear caliper. AFAIK, it rolled out of the factory that way. Regardless, either will work.

I've rebuilt both and there are several differences between early and late, but none that affect fit (or performance). The internals can't be interchanged but either should bolt right up to the car.

[StarBear]

I have an early/mid '74. Came with the two bleeders but an inexperienced garage put on early 1 bleeder calipers in 1984. Worked rather OK though the drivers side ended up binding a bit. Recently replaced with rebuilt late (2 bleeder) units; work perfectly with no adaptors.

[JFJ914]

You left out the mounting bracket for the brake shield, it sets the caliper/disc clearance. The washer replaces the bracket. All the calipers are physically the same.

[davep]

I agree, the bracket is missing that supports the brake shield. Critically, it spaces the caliper to the arm so that the rotor is centered in the caliper opening. The bracket is 2mm thick, but a large washer of the same thickness will be acceptable.



The early (1 bleeder) caliper is substantially different in construction than the later 2 bleeder version. The early caliper has 8mm adjuster shafts and the later has 10mm adjuster shafts, so the pistons and mechanisms inside all all different. However a piston + adjuster set can be swapped as a unit. The caliper halves are also different since the early type uses bolts & nuts to fasten, and the later type uses just bolts; therefore the caliper halves are not interchangeable as is. Still, there is nothing in the way to physically prevent using a late caliper in place of an early caliper or in place of a 914/6 caliper if the bracket is in place.

[Literati914]

So, is there any advantage to having the later rear calipers? .. I've got several rear calipers that will need rebuilding (I'm sure some are the later ones) and two '72 project cars - that I'm not necessarily trying to keep original. So, would you guys opt to use the later ones? Porsche must have thought it was worth switching to them, right?


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[wbgoggans]

You left out the mounting bracket for the brake shield, it sets the caliper/disc clearance. The washer replaces the bracket. All the calipers are physically the same.

Wow, that was a big oversight. Mine were a bit rusty so I was sanding them down and treating the rust. Decided I might as well put them on to test fit everything but didn’t even think about the effect that would have. Guess you should probably do brake work on a fresh mind not 4am right???

[wbgoggans]

So, is there any advantage to having the later rear calipers? .. I've got several rear calipers that will need rebuilding (I'm sure some are the later ones) and two '72 project cars - that I'm not necessarily trying to keep original. So, would you guys opt to use the later ones? Porsche must have thought it was worth switching to them, right?


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I’m one of the more inexperienced members on here so take my input with a grain of salt but on the front the switch over was a cost cutting measure so they could use a VW 411 spindle vs a 911 part number. Feel free to correct or add anymore information to this statement

[davep]

I do not see any significant advantage to the late rear calipers; I tend to use whatever was used on the car originally.
Cost savings may have been the reason to use some VW parts on the 914/4 suspension, but I would rather see facts & figures that would prove that. There was little actual use of the VW wheels, so how much savings could there be? Using 911 wheels could have reduced the cost of the 911 wheel resulting in some cost savings for the 911. The 914 struts have more in common with the 911 than any VW, so again using 911 parts would have saved costs on the 911. In fact, only the front brake rotor was a common VW part that was a critical part of the 914/4 design; the brake calipers are pretty much interchangeable so not a critical design feature.

[Literati914]

So, no practical advantage to the dual bleeder set up calipers?

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