Jeff Berk

The same thing can be said for most Zs I've seen for sale.

I ran across this on e-bay for $136 w/ shipping and was wondering if its worth picking up to aid in keeping the engine compartment cool. I have an early 260z but I suspect this design for the 280z matches. If I sand it down and if it fits in the powder coat oven, I think I can make it look nice for the cones I drive over in Autocross.

HS30-H I learned of the similar Jag bleeder last night while researching the Sumitomo. It appears to have also been used in some Studebakers like the Avanti. A post on a Studebaker forum suggested just cutting off the tip of a modern bleed screw to create one. The Jag screws, at least the one I found a reference to were 3/8" 24 thread although they also used a 3/16-inch ball. Captain Obvious The treading was a little messed up on the original bleed screw, possibly from being over tightened but the caliper's threads seemed to be fine. The old screws were tightened to the point where the flat tip was deformed by the ball bearing. I just came back from the makerspace where I modified a pair of bleeder valves I had on hand. The photograph shows from left to right, an unmodified bleeder, a modified, and the original. The original likely had a flat bottom when new but was damaged as mentioned above. I decided to mill a shallow 3/16-inch diameter concaved surface to secure the ball instead of just making a flat surface. This was likely unnecessary. I then spun the 3/16 end mill by hand in the caliper where the ball seats to clean it up a little. I might try and assemble this and see if I can draw a vacuum with the valve closed to test for leaks.

Does anyone have an opinion on machining a modern bleeder screw to match the one used in the mk63? There was a person on Jauce.com that RIP260z pointed out that was selling some reproductions that I suspect were just modified modern screws. It seems like all you need to do is cut or grind a flat spot on the end of the cone, then grind a 3/16-inch dimple in the flat spot to fit against the ball.

I think I got the threading issue taken care of with a tap and cleaning up the threads. The bleeder screw appear to just need to press against the ball bearing to seal the port in the caliper unlike the more common design that requires a precise fit of the conical end of a bleeder into a matching profile in the port. I'm not too fond of the placement of the bleeder between two protrusions in the caliper, however. This design makes it difficult to close the valve while keeping a bleed drain tube attached.

I ordered the parts, the above items from Amayama excluding the bleed screws and ball that were NLA. The brake pads are coming from Jauce. I'm getting the balls for the bleeders from McMaster for about $8.50 for 100 and some washers for mating the two caliper halves. The measurements of the balls and the washers appear to be closer to inch than metric dimensions. I have a few weeks of down time to prep the calipers. I'm planning to clean up the caliper halves and powder coat them; hone the cylinders, clean up the best pistons with crocus cloth and replace the four pitted ones. I might replace the four pins that hold the brakes due to corrosion using stainless steel rod. I have a Wilwood 1-inch master cylinder I bought off someone that I'm trying to figure out what to do with since I'm no longer going with the Toyota 4X4 brakes. Is there any advantage to installing this unit over staying with the OEM?

I don't know how safe a site they are, but I found everything I needed (except the pads) at Amayama.com. I'm still tearing down the brakes and so far I only need one piston and possibly one bleeder valve replaced. Unfortunately, my 260 will be down for a few weeks waiting on the parts.

RIPZ Thanks for the heads up on the auction. I've purchased parts from Japan before but never at auction. Now I'm torn between completing the Toyota upgrade or staying with the mk63 upgrade by a previous owner. If I go the Toyota route, I can keep or sell the mk63. If I go with the mk63 route, then I can return one of the calipers and the two rotors to Rock Auto. The pads and one caliper are not returnable because they have been installed. I'm thinking maybe the mk63s are the better choice if the pistons are not pitted. Jeff

Zed Head, That's not a bad idea. I think I'll give it a try. Once I know the thickness, I can machine something at the makerspace. Jeff

I'm going to check with T3 on which of their spacer will work to be on the safe side.

HS30-H Thank you for the diagram. The thickness (15mm) was something I was missing if I wanted to go ahead with using the mk63's. I still hope to figure out what I'm missing on the Toyota conversion. I also need to verify the mk63's are in usable condition.

BTW, I just got a quote from Brake Materials & Parts in Fort Wayne, IN to re-line my mk63s (assuming the bleeder valve is working). It would cost $50/pad plus $30 shop fees (i.e. $230 plus tax and shipping).

The brake caliper flange is not threaded so the caliper needs to move inward then the bolt will go through the caliper flange and into the threaded attachment point. If I install the spacer, I think that will move the rotor outward and move the caliper in the wrong direction.

The bleeder seems to thread in better since I cleaned up the threads. Here's a few more pictures of my Toyota installation problem. I tried reseating the hub but that didn't help. It looks like the hub is fulling seated.

It looks like my caliper needs to move inward about 5mm. I wonder if I did something wrong when I repacked the bearings.

When installing the Toyota 4x4 brake components shown on the list below, are any spacers needed? The holes are in the right place to mount the caliper but it doesn't seem to be lined up correctly. Is the mounting bracket for the Mk63 different?

Yes, I'm going to autocross the car and I suspect some people need the MK63s to meet requirements for historic racing. I'm switching to Toyota 4x4 with vented Z rotors. It looks like I'm going to have to upgrade my master cylinder as well.

Anyone know what a set of MK63s in need of new pads and possibly a bleed screw ball bearing worth? I'm assuming the pistons are in good shape because the brakes were wearing evenly. I was going to send them back for the core charge until you experts out there pointed out they were not Toyota units. That would of been a waste.

The owner back in around '83 did a major set of mods on the car including front brakes that were recorded as being from a Nissan racing catalog or something. They were last rebuilt in 2008 unless I'm missing some documentation. Now a new question to all you experts... I have a pair of new Toyota 4x4 calipers, rotors, and brake pads on order. Do I want to rebuild and reinstall what I have or replace?

I'm planning on going with new calipers so that should be the end of the hack job. I now know what happens if you over torque a bleeder screw. I usually look for an upgrade when I replace items so this seems like a good time to install better brakes. I'm not going to go the S12W route since that would be two steps up and complete overkill. The wide opening S12 + 8 with vented disks will help dissipate heat better than the solid rotors I have now. I'm assuming I can get away with my existing master since it was used with the original upgraded brakes. I'm hoping I can avoid having to use a spacer since I'm using NOT going with the S12W. I just found the answer to my "what's an SF model".

Looking at S12+8 vented, the listing on Rock Auto for 300zx identifies rotors for SF and non-SF non-turbo models? What's the difference?

Thanks Zed Head, OK, change in plans... I looked up this caliper and rotor set on Rock Auto and I'll just replace both sides. Any comments on my selection? The master cylinder seems to be working with the 4-piston unit I have so I'm assuming there won't be a problem. My current rotors are non-vented so this will be an upgrade. https://www.rockauto.com/en/moreinfo.php?pk=14177489&cc=1277502&pt=13824&jsn=1318 https://www.rockauto.com/en/moreinfo.php?pk=9744168&cc=1277502&pt=1704&jsn=1250

I was bleeding my brakes when I ran into an issue with the front right. The bleeder was loose but held fluid. When I removed it I found that the threading was damaged and the seat on the valve was chewed up. I tried a new M10 1.0 valve and it would not seal. I'm going to have to get a new caliper but I don't know if I can identify what was used on this upgraded brake. It's a 4-piston but I'm not sure what to order. I also need pads so I want to make sure I get pads that match my other caliper along with the replacement caliper.

I can give you two options, the one I generated and another one posted here: https://www.thingiverse.com/thing:6152862 They are similar but the thingverse has the tabs to hold it in place located differently. You'll likely need to sand the final product to smooth it out. The chrome vinyl is available on Amazon or any vinyl wrap shop. Let me know if you need another file format. It was originally created in Autocad Fusion 360. Finisher Final.obj

Well done!