I'm trying to understand what you're saying (I really am), but it sorta sounds like you're saying that the hydraulic force is only being applied to 1/2 of the pistons?

 

@Max Headflow knows his ****, but I don't think he's right. Wouldn't a floating caliper only have pressure applied to one side? A rigid mount 4 piston would have pressure applied to all 4 pistons. I could be wrong

 

Any 4 piston caliper I have seen has a passage to allow fluid and pressure to be applied to the back of each piston in each half.

Some car 4 piston calipers have a brake pipe fitted to let fluid in each half.

WP

 

Let's say you have to guys that can push 100 lbs.. If one guy is pushing against a wall he is pushing 100 lbs. The wall is essentially pushing back 100 lbs because it ain't moving. Ok Remove the wall and replace with another guy that is pushing 100 lbs against the other guy. Does that mean both together are making 200 lbs force? If there is 200 lbs for wouldn't the guys get pushed apart?

Same applies brake disks. Single sided caliters that float are pushing against the wall pinching the rotor. The thing is that double sided calipers can have a more pad distance on the rotor compared to a 2 piston single sided floating caliper. It can means less drag.

 

If you have 4 pistons on 2 sides in the caliper, they are connected.

 

Here's another way to look at it. Let's say you have to move each brake pad 1mm to get it to squeeze the disk. If you have a floating caliper with pistons on one side, those pistons have to move a total of 2mm to apply the brake. The first 1 mm pushes the direct pad on the piston side against the disk, and the second 1 mm pushes the caliper frame the other way, moving the indirect pad against the disk.

Now, replace the caliper with one that has pistons on both sides. If the pistons on each side move 1mm then the pads on both sides will come into contact with the disk.

The amount of fluid you need to move the two pistons 2mm is the same as to move the 4 pistons 1mm each.

Right?

 

That's one way of saying it Correct sir

WP

 

SpeedKings replied and suggested that the 11/16" master should be fine, I don't know man, after all the research I've done it appears that 19mm is what's needed. I can get a reverse bleeder for about 50 bucks, so I think I'll do that first to make sure there's no air left in the system, and if that doesn't make it right, I'm going move to the Brembo master and deal with the looks of it.

 

you wont get the hard pull like stock on those brembos - you can try the updated master from harley in 11/16 but the probably is the pistons are way bigger than stock, so theres a lack of pressure at the caliper.

 

What are you using to "T" the brake line?

Looking at the calipers they look to be tilted towards the back some. You might want to try an make them more vertical.. Loosen the fork mounts, remove the bottom bolt and tilt back, tighten the top bolt to hold in place. I

When bleeding brakes, the masters do the best if you pump real slow.. I suspect that they can pull air in from where the lever plunger goes into the master cylinder body if pumping fast.

I've had the best luck using a mityvac for initial bleeding then pumping slow with the master.