Bleeding/fluid Replacement On Linked Brakes W/abs On 6Th Generation (The Ultimate Guide)
Posted 06 April 2012 - 05:56 PM
Left and ride side are determined as if you were sitting on the motorcycle.
Images come after descriptions.
LBS: Linked Braking System
LPCV: Left-side (Servo) Proportional Control Valve (Battery side)
RPCV: Right-side (Rear) Proportional Control valve (Opposite battery side)
LMC: Lever Master Cylinder (Front)
RMC: Rear Master Cylinder (Pedal)
SMC: Secondary Master Cylinder (Left-Front Caliper)
FSM: Factory Service Manual
One man bleeder kit (optional)
ATE SuperBlue Dot 4
Speed Bleeders Part Numbers:
Front right caliper SB8125
Front left caliper outer bleeder SB8125
Front left caliper inner/centre bleeder SB8125
Rear caliper outer bleeder SB8125
Rear caliper inner/centre bleeder SB8125L
Clutch bleeder SB8125L
Part 1: Theory
Part 2: Diassembly And Prep
Part 3: Procedure
Part 4: Assembly
Part 5: Clutch
Part 1: Theory
The LBS is confusing for some when it comes to understanding how it works. The function of the sytem changed from 5th generation LBS to 6th generation LBS. I'm not too sure what the changes were, but I do know they operate differently. The way the 6th generation LBS works is; when the front lever is applied, only five out of the six (three pistons in each left/right caliper) caliper pistons actuate as well as the centre piston in the rear caliper leaving the left caliper centre piston untouched.
When the rear pedal lever is applied; only two out of the three rear caliper pistons actuate as well as the left front caliper centre piston. The LBS only works when the motorcycle is moving however, you can test this by propping your bike on the centre stand, rotating the rear wheel and applying the front brake; the rear wheel will not stop spinning.
The way it works is by force. The SMC is mounted above the left caliper that's attached to the fork and with the motorcycle moving, the rider will apply the front brake which squeezes the pads on the rotor and that drag pivots the left front caliper up which actuates the SMC and brake fluid gets pushed through to the LPCV and then to the rear caliper centre piston. The rear doesn't work in the same way because there's actually a brake line that goes all the way to the front left caliper that actuates that one centre piston by it's lonesome with the application of the rear pedal.
Thanks to BartmanEH for the above picture!
Part 2: Disassembly And Preparation
You want your bike to be on a level ground and prop the bike up on it's centre stand for this whole procedure. Rotate the handle bar all the way to the left so the LMC is level. Remove both screws and remove all the old fluid inside the LMC. You can use a turkey baster or rags, whatever you wish. Once the old fluid is out, fill it up with fresh new fluid. Make sure you squeeze the front lever a few times just incase you got any air bubbles when removing the old fluid.
Using an allen wrench, loosen, but do not remove the left front caliper bolts.
Remove the seat and do the same procedure you did for the LMC to the RMC. Don't forget to press the pedal lever a few times to remove any air bubbles.
Remove the rear wheel.
Remove the two bolts that hold the rear caliper together. The inside one is tricky and I needed to use a long 12mm socket to reach it. Once the rear caliper is removed, mount it at the 10 o'clock position on the rotor. The reason for this is so the inner/centre bleed screw is facing up, not parallel to the ground.
Part 3: Procedure
The procedure and order we're going to follow is the same one listed in the FSM, but with more pictures and explanations. Sections C. and D. are the most difficult. You will need a helper as well.
USING FRONT MASTER CYLINDER LEVER FOR A. AND B.
A. Left Front Caliper, Upper/Outer Bleed Screw
This is basic bleed. Open very slightly, usually about a 1/4 turn and pump the front lever until new fluid comes out. Even though I use speed bleeders, I still pressurize it old school method just to be on the safe side. The old school method is; with the bleeder screw closed, have your helper pump the front lever five times and hold. While holding, gently unscrew the bleeder screw until fluid comes out and before the lever reaches it's maximum travel, tighten the bleed screw. Top up the fluid level.
B. Right Front Caliper, Single Bleed Screw
This procedure is the same as above. Make sure you keep an eye on the fluid level as it drains.
USING REAR MASTER CYLINDER PEDAL FOR C. TO G.
C. Leftside PCV (Battery side), Single Bleed Screw Actuated via SMC
This step is the most confusing and difficult one as it requires good timing between yourself and your helper. The SMC is not attached at all to the front lever in anyway. You can unscrew the LPCV bleeder screw and pump the front lever all day long and no fluid will get pushed through. You could manually actuate the SMC by hand and only a little bit of fluid will come out and then stop. The correct method to do this; from what I've gathered on how the system operates and without using a vacuum bleed tool is as follows.
Remove the two bolts that hold the left front caliper on. I used an aluminum L-bracket I had lying around to wedge between the pads so they don't close.
Tilt the caliper 15° from the ground so the inner/centre bleed screw is facing up.
Your helper will be on the RMC side pressing the pedal and you will be at the left front caliper in charge of manually actuating the SMC and loosening/tighten the LPCV bleed screw. The way this system works is; there's a brake line that goes from the RMC to the SMC and from the SMC to the LPCV. Because there's no reservoir at the SMC, there's no way for new fluid to replenish to continue being pushed through the lines and out the LPCV bleeder screw, however, this is where the RMC comes in.
When your helper presses the RMC pedal down, the SMC piston will get pushed out filling it with fresh fluid. Once your helper releases the pedal, you will manually actuate the SMC by pressing it in to the caliper with your hand and fluid will get pushed through to the LPCV bleeder screw.
Push the SMC in with your hand.
Do not release from this point. Tell your helper to press the pedal again which will forcefully push the SMC out and then once your helper releases the pedal, you will manually push the SMC in again watching for new fluid. Once fresh fluid is coming out, I performed a final pressure bleed by tightening the LPCV bleeder, asking my helper to pump the rear pedal five times and release, then I loosened the LPCV bleeder screw and manually actuated the SMC gently half way and then tightened the bleed screw.
Note: Even with speed bleeders installed, I did not manually operate the SMC more than once for safe measure. To further elaborate on this; continuously pushing in the SMC numerous times will not bleed the SMC to LPCV brake line because there is no reservoir at the SMC. You will push whatever fluid is in the line and it will become empty with air. One manual push of the SMC followed by one rear pedal actuation by your helper.
D. Rear Caliper, Inner/Centre Bleed Screw Actuated via SMC
This procedure is the exact same as the above. The only difference is, you're bypassing the LPCV and going all the way to the rear caliper inner/centre bleed screw. Pressurize the sytem the same way as above too.
E. Rightside PCV (Opposite Battery), Single Bleed Screw
This is the easiest step. Follow the procedure as in Section A. but using the RMC pedal.
F. Rear Caliper, Upper/Outer Bleed Screw
Another easy step, follow above procedure.
G. Left Front Caliper, Inner/Centre Bleed Screw
The last procedure, again very easy, same as above.
Part 4: Assembly
Top up both fluids if they are low and fasten all caps and lids back on the reservoir.
Attach the front left caliper and torque the pivot and joint bolts to 23ft-lbs. The FSM says always use new bolts, but I cleaned up the old loctite residue, re-applied some new medium strength loctite and re-used them.
Attach the rear caliper and torque the joint bolts to 23ft-lbs. The FSM says replace also but I did the same as the front caliper bolts.
Reinstall the rear wheel and torque bolts to 80ft-lbs.
Now would be a good time to prime (pump a few times) your front lever and rear pedal lever. Once primed, they should not travel a lot of distance; they should feel stiff. If for any reason the levers travel a larger than normal distance, then there's probably air in the line somewhere or you might have forgot to tighten a bleed screw.
Note: The FSM says to use new bolts, not because there is something wrong with the bolts, but because there is probably some sort of loctite already applied to the threads. Thank you Metallican525 for that insight.
Part 5: Clutch
I don't have to go in to any detail about this because if you just did your whole brake system, might as well do the clutch as it's very simple and same procedure at Part 3, Section A. Remember to turn the handle bars to the right though.
At the end, I took my bike for a ride and I had no idea that this bike has this much braking power! Mind you, my fluid was 6 years old which was probably the cause of that but this method works flawlessly.
I hope this DIY was very thorough and gave you a good understanding on how to tackle this easy but tiresome procedure!
Posted 06 April 2012 - 07:20 PM
Posted 06 April 2012 - 07:56 PM
Nice writeup, sure to be usefull as the procedure is rather involved and a pain in the rear compared to bleeding "regular" brakes. I would like to point out, however, that the FSM usually reccomends bolt replacement for a good reason. In this case it's probably not because there is anything wrong with the bolts, just that the new ones probably have some sort of threadlocker allready coating the threads. I personally like to put a dab of medium strength threadlocker on nearly all the fasteners on the bike, cause they vibrate and things come loose without warning. Might wanna add that to the re-assembly instructions, might not, just my opinion.
You're right! I actually did use medium strength lock tite when i assembled everything so i will update the original post when i get to my computer!
Posted 06 April 2012 - 09:45 PM
Posted 14 August 2012 - 11:41 PM
Posted 15 August 2012 - 12:08 AM
Just had my brakes and clutch bled two months ago for the first time on my '06.
I'll be sure to save this DYI for next time.
Posted 13 November 2012 - 01:32 PM
Also, for the record, I never remove the front left caliper for fluid replacement - I just manually actuate the SMC with the caliper in place. Works fine and you don't risk wearing out the mounting bolts or squeezing the pads together making reassembly difficult.
I'd also like to point out that with speedbleeders, when doing the SMC line, if you don't close the speedbleeder on PCV, the rear pedal will not force the SMC back out very effectively - most of the pressure seems to bypass the SMC and escape out the PCV speedbleeder. I figured this out too late after doing two bikes' fluid replacement. For that line you really are better off closing the valve between SMC squeezes. The problem is that the speedbleeders have sealant on the threads and don't like to turn easily and will get the sealant worn off quickly if you do close and open it so many times. I'm going to look into getting a fancy (expensive) Stahlbus bleeder for at least this one troublesome position - they're designed for maintenance free opening and closing.
OEM Honda hard cases, Emgo 42-90931 foam grips, PowerBronze hugger (modded for stability), Vista Cruise #MCVICO throttle lock,
Posted 13 November 2012 - 06:05 PM
Edited by PorradaVFR, 13 November 2012 - 06:05 PM.
Posted 14 November 2012 - 12:16 AM
follow the book to the letter
have lots of patience
have more brake fluid on hand than you think you need (two standard sized bottles should do the trick)
use some loctite on the fasteners when you torque them back down, Honda says replace, but it's really only because of the threadlocker that needs replaced
Posted 14 November 2012 - 02:30 PM
Jay, the photo in "G. Left Front Caliper, Inner/Centre Bleed Screw" shows actuating the SMC, but I think this line is done with the rear brake pedal - please confirm.
Hey, the picture looks like it's actuating the SMC but it's really not. This is the same line that fills the SMC so you can bleed the LPCV and the rear caliper centre bleed screw via the SMC.
Hope that clears that up