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Rebuilt my brakes. CBS is a maintenance nightmare!

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The engineer at Honda who green lighted the combined braking system must have been a masochist, didn’t do his own maintenance or sold his personal motorcycles prior to a brake system tear down.

 

I rebuilt all three calipers (cleaned the pistons, replaced all seals and boots, installed new pads) and the front master cylinder. I would have rebuilt the SMC and rear master cylinder had I known the amounts of disgusting sludge that was in the system. There’s also the delay valve and proportional control valve which aren’t even serviceable units.

 

Short of pulling all the hydraulic lines and tubes and running hot water through it, following the bleeding process in the service manual is the only way to clean out all that sludge. And what a chore that was.

 

I miss the two piston single caliper front with single piston rear brake on my Hawk GT. What an easy affair that would have been to rebuild.

 

 

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Great job on the rebuild, but think you shouldn't be too hard on Honda!

My three previous VFRs with combined braking systems performed flawlessly.

 

The blame for the terrible state of your hydraulics is the previous owner. If the brakes and clutch were properly flushed/bled within every two years I'd doubt you'd be going through this process.

Hope it all goes back together well. 

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Honda really has no control how the bike is maintained after it leaves their hands. So the PO is the sole

culprit in this case.

 

I installed Galfer stainless lines and bleeding the brakes was no big deal. Granted more complicated than

a straight system, but really was not an issue. Used less than a quart bottle of brake fluid and did the whole

thing over a weekend. Of course your rebuild is much more complicated than mine.

 

Just my opinion, but install Speedbleeders while you have it apart. They are well worth the money.

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I cheaped out on the speedbleeders. In retrospect, speed bleeders would have been money better spent than the generic vacuum bleeder from Amazon. What a clumsy mess that was. 

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Get the speed bleeders,with all the hoses junctions and linked brakes they really help.Dont forget the one under the seat.Download factory service manual lots of info there. I also saved the old bleeders so if i sell her ill retrieve the speed bleeders. Good Luck.

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Well, the good news is that the brakes work. 
 

Took her to an open parking lot and did a bunch of emergency stops from 25mph. Both lever and pedal are initially “gentle” and progressively “firm”. Rear brake is good enough to lock up the rear. Didn’t try to lock up the front, ☠️


Both brakes are good enough to smash my tender bits into the tank. 

 

Once I was comfortable in the parking lot, took her around town to get reacquainted with the brakes. Once I was comfortable with the brakes, took her to a low speed, tight turn canyon and did a couple runs.

 

I had my fingers crossed for dramatic difference based on the neglect, but honestly the brakes don’t feel much different than before the rebuild. I do have peace of mind knowing that the pistons are not corroded and stuck, and the fluid and pads are fresh.

 

Probably will install speed bleeders and flush the system in 12 months just for good measure. 

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I'm impressed by how methodically you organized all the parts - looks good.  Sounds like you have it sorted.   Your bike is lucky to have a new owner that's giving it the respect it deserves.    :fing02:

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30 minutes ago, Cogswell said:

I'm impressed by how methodically you organized all the parts - looks good.  Sounds like you have it sorted.   Your bike is lucky to have a new owner that's giving it the respect it deserves.    :fing02:

Thanks. It made re-assembly a lot more efficient. Took the assembly line route and did one task to all calipers at once rather than building one caliper at a time.

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Good job on the refurb.  I agree the PO didn't flush his brakes..... I do mine annually.  YOu might want to check out the clutch slave too.

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I rebuilt the clutch master cylinder and slave a couple weeks ago as a warm up exercise for the brakes. It was actually in worse condition than the brakes.

 

Clutch MC was leaking fluid at the lever. The slave piston required a lot of elbow grease and 2000-grit wet sand to polish out the scaled up brake fluid. 

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:tongue:

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There are a few things on the VFR where it feels like the engineering department just couldn't stop designing. 

 

That said, when working correctly, the linked brakes are really quite good, and the ABS makes it even better. It all weighs a ton, but I appreciate the work they put into the system on long rides when the fatigue starts to kick in or tje weather unexpectedly turns a little more "maritime" than expected. 

 

You obviously have a good handle on working in a logical and orderly fashion. 👍  I sometimes wish I could operate that way, but my own vaguely orchestrated chaos works for me so... 

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The seals and dust cover go in one way or are they angled to retract the piston or not.  Thanks.

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They are not angled but square. Doesn’t matter which way they go in.

 

The square also functions to retract the pistons once pressure is relieved by the master cylinder retracting. 

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thank you.

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Just went through this nightmare on my 98 VFR 800... couldnt figure out why the rear brake was dragging,

turns out its proportioning valve under the tank was sticking, would have replaced but no longer available .

 

I flushed the system several times and it seems to have improved but I really want to take that valve apart and clean it inside .....

Problem is in order to access the spring cover plate screws the solid brake lines need to be completely removed from the valve and the bike under the seat.

 

The kick in the butt is that there would have been plenty of room to access and remove the cover plate had they just routed those brake lines  1" lower.

Ugh ! 😩

 

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13 hours ago, RC30guy1 said:

The kick in the butt is that there would have been plenty of room to access and remove the cover plate had they just routed those brake lines  1" lower.

Ugh ! 😩

 

...ours not to reason why 🙂

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Okay, it’s been a few weeks since the rebuild, and the rear brake pedal started to feel spongy. Even at full pedal travel, there would be virtually no braking power for the rear. Pumping the pedal did help, but rear pedal would turn to sponge after a few minutes. Rear brake was essentially useless for stopping the bike at almost anything faster than walking speed. 

 

I ordered speed bleeders, silicone hose and the bag. What a difference that made in bleeding the system! It’s just so much easier AND FASTER than using a vacuum bleeder. I’m ready to toss the vacuum bleeder in the trash.

 

This time when I bled the front center pistons, some air along with a significant amount of old dark fluid came out. This is the nasty old fluid that I thought I flushed out the first time. 

 

Also followed the service manual very closely. I must have gotten out of sequence the first time when removing, positioning, and re-installing the SMC. This time when I bled the PCV, I got a bunch of dispersed air bubbles in the fluid to come out along with a loud “PPPFFFTTT” and a few inches of solid air before nice clean brake fluid came out. All that air was still in the lines!

 

I also re-bled the front outer calipers (front lever) just for good measure. Few tiny bubbles there, too!

 

Now, pedal feels nice and firm but very responsive with good bite and power. Front is also improved with noticeable initial bite with progressively increasing power. None of that “gentle”, vague initial bite feel or rather lack of feel at initial application.

 

For anyone thinking of servicing their brake hydraulics, forget the lame vacuum bleeder. They’re just so clumsy. Get the speed bleeders and the little baggy. It’s completely worth it. I was blind but now I see!

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The vacuum bleeders work okay as long as you get a good seal with the bleeders, but that rarely happens. I've tried it a few

times and just decided, like you did, that the hassle wasn't worth the payoff. Speedbleeders work a treat.

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