Posted on Wednesday, September 02, 2015 - 02:35 pm:
As many of you are probably aware, the brake lever on the 1125s will develop some slop--sometimes as much as nearly 1" of free play. The temporary fix is to push the caliper pistons back into the caliper--this will remove the brake lever slop and usually lasts for several hundred miles before the slop begins to return.
About six months ago, someone posted about how the brake master cylinder from the FZ6 (I forget what years.. I feel like maybe '04-'11 or something like that) was externally identical to the 1125 MC but had Brembo guts, and that it was a big improvement over stock. I bought one and sure enough, instead of the N, it had the little B logo on the cover.
I finally got around to installing it along with some new Dunlopad HH+ SDP993 pads last weekend. I used an air-compressor-powered vacuum pump, which did an awesome job of getting the air out of the lines in a matter of seconds. Just to be thorough, I pumped up the lever and sucked out the fluid a half dozen more times.
Sure enough, the lever felt awesome. But, after a 250-mile ride on Sunday, the lever felt like it had developed some slop again. I re-bled the brake but that had a minimal effect.
While the reservoir cap was off, I could see fluid moving around as soon as the brake lever moved even the slightest bit. I had to be careful to move the lever very slowly, as moving it quickly would result in fluid spurting out the top of the reservoir.
This leads me to think that the problem isn't necessarily with the MC itself--if fluid appears to move with the slightest lever input, then presumably that means that the piston inside the MC is working properly. But, I don't understand how the issue could be anywhere else in the front braking system.
I haven't pushed the pistons back into the caliper yet, but I'm confident that will (temporarily) remove the lever slop.
I have been hesitant to switch to a different brake MC because I like retaining the look of stock, and if I went to a pee-cup reservoir brake MC, I'd feel compelled to do the same for the clutch MC so that they'd look similar. That's more expense than I'd like to absorb.
Posted on Thursday, September 03, 2015 - 08:16 am:
I went with an RCS-19 and the place I ordered it gave a free Brembo pee cup. Once you feel the difference in analog control and Feel you will forget about the looks.
Highly recommended upgrade.
Hardracing.com. Mods please delete it you don't want this link. No affiliation here other than a great product at a good price.
Posted on Thursday, September 03, 2015 - 12:05 pm:
To be honest, I'm happy with the feel of the Brembo FZ6 MC, or even the stock MC. I'm just irritated about having to push the pistons back in every few hundred miles. I'm worried that I'll damage the pads or rotor with the screwdriver I use, plus just doing it is something that shouldn't need to be done. But if the alternative is spending several hundred bucks on an aftermarket MC (especially if it won't match my clutch MC), then I will probably just deal with the brakes as-is.
Posted on Saturday, September 05, 2015 - 02:41 am:
Pushing the pistons back in breaks up the road grime that gets stuck between the piston seals and the pistons.
Using brake parts cleaner to blast the roadgrime away works better. But roadgrime will always accumulate. It's a normal maintenance event. I typically run a few thousand miles between cleanings.
Posted on Thursday, September 17, 2015 - 01:33 am:
I've done this on hundreds of Harleys and a good handfull of buells, to include three of my own. I'm sure all brake systems have some amount of freeplay. But after doing this, your brakes will feel like they did the day your bike rolled off the assembly line - no more spongy feeling, more of a hydrolocked feeling. Try it and tell me what you think.
I may not have made it clear in the video, but you want to pump the pistons out one side at a time. First clean one side, then the other. As long as you keep a brake pad in between the pistons, you're not going to pump them out past the seals.
I guess the "road grime" is probably mostly brake dust from the pads.
Posted on Saturday, September 26, 2015 - 04:38 pm:
I bit the bullet and got a new Brembo RCS19 and reservoir today for $350.
Nice stuff!!
- install was pretty easy - needed to adapt the wiring for the brake light switch. I cut off the Brembo connectors, modified some standard blades to fit the Buell's wiring, soldered those in, shrink wrapped it all nicely. - I have a slight issue nearing full lock turning left where the lever travel adjuster hits the speedo cluster and activates the brake lever if I keep turning. I played with different locations, but didn't find a better solution. Not really an issue for me
- Very consistent lever now
- power feels about the same, maybe a little harder to pull **but** I haven't played with the MC ratio screw either, so the other setting might be an easier pull
- travel adjuster works great
- feels far less likely to bottom into my fingers on the grip now
- consistent
- did I mention consistency?
- went ahead and pulled the caliper apart, cleaned, lubed (brake fluid) and reassembled. I rebuilt it a few months back, so I knew the parts were likely fine