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Old May 31st 2018, 23:22
H2OSB H2OSB is offline
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Join Date: Jan 2003
Location: Modesto, CA
Posts: 175
Little update. So the brakes I'm doing for the front of my 1303 are the following: I'm using Porsche 944 spindles with a "flip-it kit" to relocate the direction of the tie rod ends. Due to this, I'm also using Kerscher ball joints. For the actual brakes, I'm using 944 rotors that have had the DIAMETER reduced by 1 inch (25mm). This allows a typical Porsche 914 caliper to bolt onto the 944 spindle and have enough swing clearance for the rotor to fit inside. The rotors diameter PERFECTLY places the 914 (D30) pad on the rotor. Now, obviously, 914 calipers are made for 11mm wide solid rotors and the 944 vented rotor is 20mm wide. This is corrected by salvaging the spacers from a set of Porsche REAR M calipers.

The Porsche rear M calipers is the SAME casting as the 914 EARLY front calipers, so if you can find a set of the rear calipers in good condition, all of the hardware can be used (bolts, spacers, pad hangers). This is important because both the 914 caliper and the rear M caliper use non-standardized M7 bolts, the M calipers bolts being the infamous Ribe bolts (pronounced ree-bee) which have been out of production for about 40 years, and cost roughly their weight in gold, assuming you can find them. That said, the longer bolts are required to compensate for the width of the spacer, however, one could use the longer of the two original 914 caliper bolts as the shorter bolt once the spacers are in place, and just get longer bolts for the other spot. In my case, the rear M calipers I purchased had three of the Ribe bolts ruined due to some previous owner attempting to use the wrong tool to remove them. A Torx head of the correct size can be used to remove them, however, torquing them, it's suggested by "those who know" to use the correct Ribe bit.

Both Lanner Khan (aka Flat) and my machinist friend (who turned down the rotors) thought me silly for what *I* did, which was purchase the correct length M7 socket head bolts from a company called Tola-tool in Germany(Tola-tool was the ONLY company I could find who offered both the correct length AND hardness (12.9) for brake caliper use.). Both suggested re-drilling the holes in the calipers to M8 (a standardized size that is FAR easier to obtain) in the case of Lanner or 5/16th inch (also standardized) in the case of my machinist friend. The reason this was silly was the fact the shipping from Germany to California was almost exactly TWICE the cost of the bolts themselves...which weren't cheap. I elected to not re-drill the calipers out of fear there simply wasn't enough material in the calipers to do this. In the end, I'm happy with the bolts. Cry once, as they say.

So, the results of my mods made for a very slick setup that seemed almost meant to be. The caliper is centered over the rotor perfectly with the use of a 2mm shim placed between the caliper mounting ears and the spindle. However, as I was fitting everything together I discovered my first (and really only) major hurdle. The outside of the caliper body hits the HUB edge when everything is bolted on place. I had been fitting everything up with a pair of junk split 914 calipers with the pistons removed to make trial fitting easier. I tried to clearance the calipers a bit but discovered there simply isn't enough material on the body where the piston lives to take material away. Fortunately, I know Flat. Lanner has had a set of 944 hubs on his bus for years that he has turned down by 8mm in overall diameter. I know from my caliper clearancing effort, I only need to remove approximately 2.5mm for the caliper to clear the hub, so 4mm is more than enough for good clearance, thus I'm sending them up to Lanner to have him turn them for me.
johnL (aka H2OSB)
'74 1303, Outlaw sedan (with a GL flavor)
'73 1303, Sports Bug look
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