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Delinked Rear Brakes are weak


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The next project is the rear brakes. When I purchased the bike, the brakes were delinked which is how I prefer. Previous owner just left all the lines, including the soft line to the left caliper just capped and wire tied to the front fork. After removing all the front brake lines that connect to the rear MC, adding fresh fluid and bleeding the brakes, I still have a soft weak rear brake. I read that guys have recommended connecting the rear banjo line to where the front line was connected on the MC for better breaking pressure. This I have not tried but will. My question is can I use the OEM rear brake line or do I have to get a longer one to make the connection?

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Well, if it's the original brake line, you'll definitely need a longer line to move the connection. But you should probably replace the rubber hoses anyway due to age and deterioration. That is if you have an '83 with the same rear MC as I do anyway. My rear MC is significantly different in configuration than the diagram in the service manual depicts.

 

My question to any who have de-linked is why not remove the proportioning valve and tie directly into the MC without the valve?

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Well, if it's the original brake line, you'll definitely need a longer line to move the connection. But you should probably replace the rubber hoses anyway due to age and deterioration. That is if you have an '83 with the same rear MC as I do anyway. My rear MC is significantly different in configuration than the diagram in the service manual depicts.

 

My question to any who have de-linked is why not remove the proportioning valve and tie directly into the MC without the valve?

 

I think thats what people have recommended on this forum.

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I am a believer that an experienced rider will setup his bike based on how he likes to ride. "My Bike, My Way"

 

True what luvmy40 is saying about old rubber lines.

 

However these bikes aren't cruisers, but do handle like a sport bike in many ways. My Gen 1.5 at speed handles better than our old Kats at speed and corner more like a crossbreed. If your running a line in a tricky curve which brake would you prefer to help hold the line past throttle?

 

I would re-link them.

 

I can say with certainty they power you down very well when linked, providing, the suspension is in good order.

 

Patch

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I gutted and reattached the valve, keeping it on the bike as a placeholder so I could use the OEM line. I did install an R6 (front) caliper on the rear and the different angle was awkward for the OEM line. It worked for awhile but it blew out on the last ride. I'll end up doing some measurements and getting a suitable non-Chinese aftermarket line. The R6 caliper and EBC HH pads did step up the rear braking power, it was a chore to bleed it until the pedal was firm and it sure wont put you over the handlebars, but it works well enough.

 

Skydoc makes a neat tidy conversion kit for delinking and installing braided lines. I was too cheap to buy it but in retrospect I should have. If the rear works as it should but just not enough grab you might try going to an HH pad, it should make a difference. I just put EBC HH pads on my Vmax and the stopping power is notably better than with the OEM pads, with no other mods.

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The next project is the rear brakes. When I purchased the bike, the brakes were delinked which is how I prefer. Previous owner just left all the lines, including the soft line to the left caliper just capped and wire tied to the front fork. After removing all the front brake lines that connect to the rear MC, adding fresh fluid and bleeding the brakes, I still have a soft weak rear brake. I read that guys have recommended connecting the rear banjo line to where the front line was connected on the MC for better breaking pressure. This I have not tried but will. My question is can I use the OEM rear brake line or do I have to get a longer one to make the connection?

 

It sounds like the system wasn't treated well by the previous owner, meaning it needs complete service. There are lots of options and opinions on setups, caliper replacements, etc., but here's what I would tell you if you brought it into my shop: "I'll need to rebuild the rear caliper and the rear master cylinder, replace any rubber hoses with stainless steel, and run piping directly from the master to the caliper, eliminating the proportioning valve by completely removing it. Otherwise I won't touch it. And my lawyer needs you to sign this 'cause this isn't a stock system. "

 

So take the above as the end goal, subtract anything you've already rebuilt and that's your fastest track to the best braking you can get with the master and caliper you have. If you want to improve with a larger caliper you can do that after and know that you're building on a solid foundation instead of shooting in the dark.

 

Hope this is helpful.

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I have delinked my 88 and went with all SS lines from Skydoc_17.

The stock linked brakes were really bad for where I drive. I have to drive on pavement with a LOT of loose gravel on it. With the linked brakes there was no way to stop without locking the front tire and risk going down.

 

I completely removed the proportioning valve and plugged the Master where the line goes to the front. I put on HH pads all around. The rear is capable of locking the rear tire if you really stand on it. You can not get more braking power in the rear than that. You do have to make both front brakes work with the front master or the total braking power will be really bad.

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This is the proportioning valve correct? I removed it and put the brake line into its socket. Capped where the front line goes. As it rides now, I dont think I could lock up the rear wheel. I've pulled the caliper and did a good cleaning but did not get new seals. I guess I still have some air in the lines.

 

IMG_20180624_132345.jpg

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What brake pads do you have. The HH do have a lot more grip. I have to hit the rear really hard to get lock up, but you really do not want to lock brakes on a bike. I played with the peddle height to get the rear braking to be just shy of lock up. I have to make an effort to get lock, so that I am unlikely to lock the rear in a panic stop.

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What brake pads do you have. The HH do have a lot more grip. I have to hit the rear really hard to get lock up, but you really do not want to lock brakes on a bike. I played with the peddle height to get the rear braking to be just shy of lock up. I have to make an effort to get lock, so that I am unlikely to lock the rear in a panic stop.

 

Really not sure of the manufacturer of the pads as they were the one that were on the bike when I got them. They have lots of life left on them. I will try to bleed the brake again (I feel like I've already done an extensive bleed on these damn things). Maybe I'll take off the caliper and hang it higher than the mount so air runs to the bleeder or I'll try reverse bleeding. Then I will adjust the pedal to where the brakes come on sooner in the pedal travel. Im a big user of rear brakes especially in slow speed maneuvers.

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Yes the 2nd gens have to much rear brake and it is real easy to lock it up so many people use organic pads to get less rear brake. The first gens have weaker rear brake so you need to use a more aggressive brake pad to get good braking on the rear.

 

When it comes to the rear brake the 1st and 2nd gens are opposites and have no similarity.

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The second gen has the exact same rear caliper as the 1st ben MK2 has!!! I think the OP has an MK1 which has very anemic brakes, to begin with! You can convert to an MK2 caliper but you need the MK2 mounting bracket, and you have to MacGyver a way to adapt it to the MK1 swingarm...

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That is a fact. I've come very close but been lucky. Practice, practice, practice....

 

I'm not worried that much about locking up the rear brake in dry conditions. But, when there is a low traction situation when the road is slippery due to rain, leaves, dirt, etc. it would be really easy to lock up the rear and go down. The only motorcyle crash I've experienced was locking up the rear of my 83 Yamaha Virago after it started raining and there was clay on the road in front of someone's driveway. I broke my ankle! Wasn't that a factor in Yammer Dan's crash going to MD a few years ago. Didn't he lock up the rear wheel?

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So I took the bike for a ride this morning after only after removing the slop in the rear brake pedal and it seems to have a little more braking power. I wouldn't call it great but the pedal is hard not spongy. Like someone else commented, I would have to really stand on the pedal to lock them up. It's liveable for now.

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The 2007 Gen 2 I just bought has a very powerful rear brake, much more so than the front. Seems to me this situation is one panic stop from going down.

 

That is a fact. I've come very close but been lucky. Practice, practice, practice....

 

The second gen has the exact same rear caliper as the 1st ben MK2 has!!! I think the OP has an MK1 which has very anemic brakes, to begin with! You can convert to an MK2 caliper but you need the MK2 mounting bracket, and you have to MacGyver a way to adapt it to the MK1 swingarm...

 

Some of the 2Gens do have a touchy rear brake, and a few have taken a dump... Rick Butler designed a delay valve to fix the problem, but I'm not sure he ever got it into production. The weaker pads may be one answer. With all this rhetoric about boosting the rear brake efficiency I kinda wonder if some may be ignoring the fronts since a high percentage of the stopping power and traction comes from the fronts during braking application. I also wonder in the weight transfer dynamics during a stop, where the rear actually gets lighter and the tire has less traction, would cause the rear tire to lock up quicker?? :confused07: :witch_brew:

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Some of the 2Gens do have a touchy rear brake, and a few have taken a dump... Rick Butler designed a delay valve to fix the problem, but I'm not sure he ever got it into production. The weaker pads may be one answer. With all this rhetoric about boosting the rear brake efficiency I kinda wonder if some may be ignoring the fronts since a high percentage of the stopping power and traction comes from the fronts during braking application. I also wonder in the weight transfer dynamics during a stop, where the rear actually gets lighter and the tire has less traction, would cause the rear tire to lock up quicker?? :confused07: :witch_brew:

 

Absolutely. The weight transfer is a major reason why the rears lock up so easily on the 2nd gen. But to be honest, a 4 piston caliper was NOT needed on the rear...and 2 pot would have been just as good, IMHO. Rick's last post on his valve solution gives the parts needed to make this modification ourselves. I'm sorely tempted to make one as my last panic stop resulted in the rear end swinging out to the right. Thankfully my reactions are still good as once I let off almost immediately, she came back in line. Another second longer and it would have been a high side accident for this kid.

 

But the bottom line here is twofold:

1: The rear brake is very good, we just need to practice emergency stops from speed so your right foot does it's job without panic.

2: For any riders new to the 2nd gens, not to panic about this problem. It's really your foot's problem not the bikes!

 

As far as the front brakes...they are good as well...but here I think the stock pads are weak. Better pads are a worthy investment.

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:sign06::hijacked::sign06::hijacked::sign06::hijacked:

 

Yes the 2nd gen has its own rear brake issues, BUT the OP is trying to figure out his 1st gen rear brake. The 1st and 2nd gens are very different as far as rear brakes are concerned.

That is not entirely true, Jeff. The rear calipers for a 1st Gen MK2 and the second Gen rear are the exact same caliper!! The difference is the 2nd gen is not linked whereas the 1st Gen is. Seems to me I remember the rotors being interchangeable as well.

 

The issue is the OP has an MK1 which uses an entirely different caliper and rotor...

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:sign06::hijacked::sign06::hijacked::sign06::hijacked:

 

Yes the 2nd gen has its own rear brake issues, BUT the OP is trying to figure out his 1st gen rear brake. The 1st and 2nd gens are very different as far as rear brakes are concerned.

 

Ya think that one's linked and the other's not might have something to do with it?? :-) :whistling:

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:sign06::hijacked::sign06::hijacked::sign06::hijacked:

 

Yes the 2nd gen has its own rear brake issues, BUT the OP is trying to figure out his 1st gen rear brake. The 1st and 2nd gens are very different as far as rear brakes are concerned.

 

I plead partially guilty for hijacking the thread because I don't want anyone else to lock up the rear wheel and break an ankle like I did. Delinking the brakes sets you up for that possibility. If I could I would link my Gen 2 brakes. ABS would be great! I suspect that if Yamaha had added fuel injection and ABS to the Gen 2 bikes it would have gone a long way in making it sell better and keep the resale higher. You can buy a Gen 2 for half what you can a Goldwing. In my case it was a 3rd.

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I am not sure where the difference comes in between the 1st and 2nd gen, but it is well documented the the 2nd gen has to much rear brake and the 1st gen even delinked does not have enough rear brake. It may just be the difference in the geometry of the brake peddle and riding position that gives you a lot more leverage on the brake peddle, but the difference is there. The fix for a delinked 1st gen and the fix for a 2nd gen are very different and doing the wrong fix could be dangerous.

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I have delinked my 88 and went with all SS lines from Skydoc_17.

The stock linked brakes were really bad for where I drive. I have to drive on pavement with a LOT of loose gravel on it. With the linked brakes there was no way to stop without locking the front tire and risk going down.

 

I completely removed the proportioning valve and plugged the Master where the line goes to the front. I put on HH pads all around. The rear is capable of locking the rear tire if you really stand on it. You can not get more braking power in the rear than that. You do have to make both front brakes work with the front master or the total braking power will be really bad.

I could have sworn that after delinking, my rear brake was touchy and would skid with moderate pedal force.

 

Sent from my VS987 using Tapatalk

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The second gen has the exact same rear caliper as the 1st ben MK2 has!!! I think the OP has an MK1 which has very anemic brakes, to begin with! You can convert to an MK2 caliper but you need the MK2 mounting bracket, and you have to MacGyver a way to adapt it to the MK1 swingarm...
Does the bracket not have the pin in the same place?&

 

Sent from my VS987 using Tapatalk

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