I've got a lot of play in my front brake lever. Once it gets to the point where the MC is actually pushing fluid, it's ok, but there's a good amt of play before i get to that point. I just bled the system (installed SS lines) and was wondering if it's just something inherent to f4i's, if something is up w/ my F. MC or elsewhere. There's a decent amount of front pad (about half) and i'm using fresh motul 5.1. Anyone else have the same issue?

thanks

 

i would say its your master cyclender...... or there is a bubble somwere in the system... the brake likes have to be straight up and down when you bleed them otherwise the bubbles will gang up...(you probably already know that)lol..

 

Yeah, the lines weren't kinked or anything, and i think i got all the bubbles out, and it feels the same as it did with the rubber lines in.

yeah, I'm beginning to think it's the MC...now the question becomes OEM or brembo or other?

edit: i really need to stop spending all my money on this goddamn bike...

 

1. sometimes it takes several bleeds to clear the system of stubborn bubbles.
2. you don't NEED a Brembo MC. The stock MC is adequate. If you want enhanced "feel" from the system you can install a MC from a ZX6R, 1000rr, 954rr, etc. I have been TOLD that they give better feel than the stock F4i.

The 954rr/929rr MC would be your best bet since the calipers are the same as the F4i Nissin's. They are just a different color. This will keep the correct ratio between the master and the pistons.

You do know that stock bikes are fast too?

P.S.

How about switching back to Honda DOT4. Last time I checked the F4i dosent have ABS (which Motul 5.1 is supposedly designed for).

 

Yeah, i figured it would take some work to get all the bubbles out, but we pushed a LOT of fluid through that system, so if i HAD to wager, i'd say it's bubble free.

It's good to know i don't need a brembo MC, i have no desire to size it, or deal with any of the extra crap, and that there's a cheaper solution. I've found a couple of cheaper F4i MC's on ebay, hopefully 954/929 MC's are just as cheap.

I know the stock bike is fast :P which is why most of the money is going to rinkadink stuff like the brake pads, oem plastics, a year's supply of OEM filters, OEM Sprockets/525 chain, grips, replacement levers, etc. I haven't really spent anything on performance mods yet, and aside from maybe a PC, i'm not sure i will. Just wanna rescue this bike from it's somewhat troubled history and less than fastidious previous owner.

I'm guessing that the lower viscosity of Motul 5.1 is probably helping, vs. hurting me in this case. I bought it for the Dry BP to Price ratio, since rbf600 is way too expensive (esp compared to what i used to be able to get it at), but i suppose OEM fluids aren't anything to shake a stick at either. Next time around...

 

I just did a fluid flush lastnight, and the brakes seem to need a couple of pumps to get rock hard feel. I have stock lines. How can I get the lines vertical to ensure the system is bubble free? At what point should I suspect bad componentry?

Original poster: It is possible to have warped rotor cause the issue you're experiencing.

 

You can stand the bike up on a rear stand or jack stands.

Also, you can get a rubber mallet and tap the calipers while bleeding. This will help dislodge any stubborn bubbles.

I am soo looking forward to installing my SS lines soon.[:@]

 

Yeah, i was wondering about the rotors, since it sometimes has a strange jiggle when i'm braking w/ medium force--though it might be something else cuz it only seems to happen when i'm going downhill. I walked the bike with the lever slightly depressed and didn't feel any anamolies.

 

Remove the rotors and check them for true by placing them flat on plate glass. Clean the mounts and remount. Use loctite and torque properly.

 

You don't need to remove the rotors to check them. Pull your calipers off and hold them away from the wheel, then take a stationary object like a pencil or screwdriver and hold it tightly against the fork tube and just off the rotor, spin the wheel. You will know immediately if the rotor is warped.

This may be a dumb question but you do know that the brake lever on these are adjustable, right. You may just need to move it away from the bar a notch or two.