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Discussion Starter #1
So I've been chasing a case of brake shudder and lockup for many months now and still no success in terms of eliminating shudder...

The brake lockup seemed to be resolved after a thorough cleaning of the secondary master and re bleeding, but the elusive shudder is still there...

It seems that the brake system must be hot for this to occur... In that it has been in the 90's here for the last month or two, reproducing it is not a problem... I simply ride over to the Cherohala about an hour away from me, ride up to the NC state line, turn around and on the way down, the shudder starts... It of course disappears if I use the front brake in combination with the rear...

I have tried just about everything I can think of with the exception of replacing all rotors and pads... You'll see a spring loaded device on my front rotor in the video that I cobbled together but that didn't produce any results either...

I have video of the rear brake assembly but that really doesn't show much... I can't honestly say that I see anything back there on the video...

I don't recall when it first started but it definitely got worse after the recall was done... Honda has a problem here that they refuse to address and it seems the only way it will get resolved is if we resolve it ourselves...

So here is the video - I suggest viewing in HD and full screen so you can see the shuddering secondary master... watch the rear of the front fender too - it telegraphs the shudder quite nicely...

I'm open to any and all suggestions...

Les

 
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Contamination of the pads can cause them to become "sticky" resulting in grabbing when they shouldn't. It is extremely important when replacing brake pads to ensure that the pads and the rotors are kept clean. Any contamination on the pads or the rotors can affect the braking quality.

I've serviced trucks where the rear brake shoes wouldn't release from the drum and the drum was extremely difficult to remove. A leaking rear axle seal had contaminated the brake shoes with oil.
 

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You need to do the Rocky bleed. This problem has been around for a long time and it seems to be caused by air trapped near the bango fitting high up on the left side of the fork.
 

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Discussion Starter #5
Answers to questions - All Honda parts, pads, rotors, etc... Yes, bike is ABS version... Have not as yet checked run out of rotors but plan to do that later today or tomorrow... I doubt that is an issue but I'll check it just to be sure...

Guys, I have bled this system (including the Rocky bleed) til I'm blue in the face, and the rotors and pads are as clean as I can make them... I'm a pretty fair wrench, but this issue is driving me nuts... The puzzling thing is I have a buddy with an 2007 and another with a 2012 and neither of them has ever had this problem, yet others such as myself are plagued with it...

Thanks for all the input - others feel free to comment...

Les
 
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You need to do the Rocky bleed. This problem has been around for a long time and it seems to be caused by air trapped near the bango fitting high up on the left side of the fork.
Biglefti, did you ever have the shudder? Have you done the Rocky bleed? Did it help you?
I would like to find a solution to it also, and I don't need to hear that if you use both brakes together it won't happen. There are times you don't use the front brake, that is when it will occur, if you don't know when those times are you may need to take a riding course. There is a lot more to riding a motorcycle than stopping at a stop sign.
 

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Would one of your friends let you try their wheel assembly on your bike? I’m calling it a bad rotor. And before purchasing new rotors, try another assembly. Just for a test.
 

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Yes, I've done it on both of my past wings. One thing about it is that it is not a permanent solution as air seems to get introduced into the system either from the front, rear, or secondary master cylinders or from the brake cylinder pucks. Where else? When it does, it wants to work it's way to that high point. It's kind of a pain to bleed and is best if you have a helper to operate the the lever and pedal. It does work when done right, but like I said, it isn't permanent.
 
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Answers to questions - All Honda parts, pads, rotors, etc... Yes, bike is ABS version... Have not as yet checked run out of rotors but plan to do that later today or tomorrow... I doubt that is an issue but I'll check it just to be sure...

Guys, I have bled this system (including the Rocky bleed) til I'm blue in the face, and the rotors and pads are as clean as I can make them... I'm a pretty fair wrench, but this issue is driving me nuts... The puzzling thing is I have a buddy with an 2007 and another with a 2012 and neither of them has ever had this problem, yet others such as myself are plagued with it...

Thanks for all the input - others feel free to comment...

Les
Contaminated brake pads usually cannot be cleaned. They should be replaced. I may be wrong, but pads are not expensive and for someone who is fair at wrenching they are easy to replace. It may be a long shot, but it seems as though you have done everything else. As to the Rocky bleed - I have often read on this forum comments from members who had success with it. IMHO the implementation of standard brake bleeding procedures with the brake bleeding sequence outlined in the Honda service manual should be sufficient to remove any air. It just doesn't make sense that the flow of brake fluid under constant pressure wouldn't expel all the air. Maybe I need to take another course in hydraulics.

If I am wrong about replacing the brake pads, you can save the ones you removed and install them when the new ones wear down, so you will have lost nothing except your time replacing them.
 
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Yes, I've done it on both of my past wings. One thing about it is that it is not a permanent solution as air seems to get introduced into the system either from the front, rear, or secondary master cylinders or from the brake cylinder pucks. Where else? When it does, it wants to work it's way to that high point. It's kind of a pain to bleed and is best if you have a helper to operate the the lever and pedal. It does work when done right, but like I said, it isn't permanent.
Maybe you are on to something with it(Rocky Bleed) not being a permanent fix. If air is getting in and you can bleed it out, it seems that when the brake lines are pressurized you would have fluid leaking out at the leaking point. I haven't lost any fluid, reservoirs are both at proper levels. And it only happens when the temperature rises. Possibly air temperature speeds up the brake lines getting and retaining heat. How is it possible to get air in and not loose fluid? And if air was getting in why would it not continue to fill the system? I'm just trying to wrap my head around all possible explanations. Like I've said in other brake posts I didn't have the shutter until I took my bike in for the recall, what changed at the dealership when they worked on my bike?
 
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Your video may shed some new light on this problem. I have long felt like the problem is inherent in the design of the linked brake system. I believe I can see your caliper oscillating up and down and modulating the secondary master cylinder. I'm wondering if this pumping action of the secondary master cylinder could be the cause of the pulsation. Or maybe it is the effect?

The problem occurs in higher ambient temps with light application of the rear brake lever. I have always wondered if the action of the delay valve slightly opening and then closing on light rear brake application may be pulsating the fluid and activating the left front caliper which then amplifies the pulsation through its activation of the secondary master cylinder. In higher temps the viscosity of the fluid changes, and that might explain why it only seems to happen in hot weather.


This problem has been around since 2002 or so, and there used to be 30 page thread about it in the tech forum.
 

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Your video may shed some new light on this problem. I have long felt like the problem is inherent in the design of the linked brake system. I believe I can see your caliper oscillating up and down and modulating the secondary master cylinder. I'm wondering if this pumping action of the secondary master cylinder could be the cause of the pulsation. Or maybe it is the effect?

The problem occurs in higher ambient temps with light application of the rear brake lever. I have always wondered if the action of the delay valve slightly opening and then closing on light rear brake application may be pulsating the fluid and activating the left front caliper which then amplifies the pulsation through its activation of the secondary master cylinder. In higher temps the viscosity of the fluid changes, and that might explain why it only seems to happen in hot weather.


This problem has been around since 2002 or so, and there used to be 30 page thread about it in the tech forum.
Fred I recall that Tom Finch had the brake shudder he did the Honda bleed, the Rocky bleed and still had the shudder. Tom found a second high spot for air to get trapped in the rear master cylinder line. He broke the brake line at the highest spot, bleed it and problem was gone... is that posible in this case..?
 

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Discussion Starter #15 (Edited)
Your video may shed some new light on this problem. I have long felt like the problem is inherent in the design of the linked brake system. I believe I can see your caliper oscillating up and down and modulating the secondary master cylinder. I'm wondering if this pumping action of the secondary master cylinder could be the cause of the pulsation. Or maybe it is the effect?

The problem occurs in higher ambient temps with light application of the rear brake lever. I have always wondered if the action of the delay valve slightly opening and then closing on light rear brake application may be pulsating the fluid and activating the left front caliper which then amplifies the pulsation through its activation of the secondary master cylinder. In higher temps the viscosity of the fluid changes, and that might explain why it only seems to happen in hot weather.


This problem has been around since 2002 or so, and there used to be 30 page thread about it in the tech forum.
I believe your right Fred... I can see the front caliper bouncing up and down as well... The issue is one of is the secondary MC causing this or is the delay valve causing this or is the front caliper to blame or is it a system design problem??? These linked brake systems did work properly when we got our bikes, so what has changed that now causes this condition???

I check rotor thickness and it is well within spec and I'll be checking rotor run out tomorrow... I was seriously thinking about resurfacing all the rotors and installing new pads to see if that helps...

The linked brake system is very complex, maybe too much so to accomplish the task at hand...

I would be very interested in the brake line that Tom Finch bled to see if that would resolve the issue... I have done the Rocky bleed several times and the complete system bleed several times and no luck with either... I had opened up the secondary master and it was quite dirty and a bit of sludge... Cleaning that and the return hole seemed to have resolved the brake lock up issue I was having but no luck with the shudder... And you are correct - it is definitely tied to heat as it only does it riding on a 90 degree day after a few hours of riding...

I'm at my wits end trying to solve this and the funny thing is not all bikes do it... My 2 buddies 2007 and 2012 have never had this issue...

I'll post the run out figures after I check them tomorrow as well as the rotor thicknesses... IIRC, the rotors are only down about .010" in thickness - plenty left to have them reground by TruDisk... I wonder if a high temp racing type brake fluid would resolve the issue?? Food for thought...

Les
 
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I believe your right Fred... I can see the front caliper bouncing up and down as well... The issue is one of is the secondary MC causing this or is the delay valve causing this or is the front caliper to blame or is it a system design problem??? These linked brake systems did work properly when we got our bikes, so what has changed that now causes this condition???

I check rotor thickness and it is well within spec and I'll be checking rotor run out tomorrow... I was seriously thinking about resurfacing all the rotors and installing new pads to see if that helps...

The linked brake system is very complex, maybe too much so to accomplish the task at hand...

I would be very interested in the brake line that Tom Finch bled to see if that would resolve the issue... I have done the Rocky bleed several times and the complete system bleed several times and no luck with either... I had opened up the secondary master and it was quite dirty and a bit of sludge... Cleaning that and the return hole seemed to have resolved the brake lock up issue I was having but no luck with the shudder... And you are correct - it is definitely tied to heat as it only does it riding on a 90 degree day after a few hours of riding...

I'm at my wits end trying to solve this and the funny thing is not all bikes do it... My 2 buddies 2007 and 2012 have never had this issue...

I'll post the run out figures after I check them tomorrow as well as the rotor thicknesses... IIRC, the rotors are only down about .010" in thickness - plenty left to have them reground by TruDisk... I wonder if a high temp racing type brake fluid would resolve the issue?? Food for thought...

Les
I bought the 2008 with at 9,600 miles, and it now has 64,450. Since day one it has shuddered, exactly as Fred Harmon describes. It is only in hot weather, in slow or stop & go traffic where I tend to use the rear brake often. Usually the first time it shudders, it's a reminder to favor the front brake more, which helps. As soon as the bike gets moving again the problem disappears. Not a big deal, I have just learned to deal with it.
 

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There have been several questions/theories poised here that need to be clarified. I wish I had the complete answer to a permanent solution to this issue, but I think I can show why it is possible to get air into the system without having a leak of brake fluid.
The brake fluid seals, specifically those around the pistons that push the pads out to the rotors are a one way seal. They are designed so that as more pressure is applied, the seal against the piston becomes stronger. However, when the pressure is released, the strength of the seal becomes less. In many ways, it is like a check valve that allows fluid to flow in one direction, but not in the opposite direction. At the other end of the seal is the wiper portion. this is designed to keep crap from the portion of the piston that is exposed to atmosphere from entering the system. It also tends to keep air from entering the system, but as wear occurs on both the piston and the wiper it is possible for small amounts of air to find it's way into the closed hydraulic system.
Next, someone thought that bleeding the system would push all of the air trapped in the system out. In theory, this is true, but in reality most of our bleeding methods (i.e. squeezing the brake lever or pushing the brake pedal) are not capable of pushing enough brake fluid at one squeeze to completely evacuate an air bubble entrapped at a high point in the system. You may say that is why we lock the exit and release the brake then squeeze it again. You are right in that assumption, except during the reload of fluid, that little air bubble has made it's way back to the high point. If you want to see this action, just take your mighty vac and using a high loop pump it a few times and you can watch fluid being pulled from a cup pushing the air in the tube ahead of it. As it passed the high point, the air in the tube will continue to migrate to the top of the loop.
Finally, why does it only do it when it's hot. For the shudder to take place, there has to be a certain amount of compress ability of the brake fluid. Since the fluid itself is not compressible, it must have air in the system. A minuscule amount of air may go unnoticed in normal operation, but a large amount results in no pedal, or a soft peddle. Since you have a peddle you just assume there is no air in the system, but there actually is usually some. I'm thinking that on very hot days this small amount of air is expanding and making it's volume greater that it now gives room for the shudder to take place .

Hmmm, based on what I just wrote, I would think the fix would require new calipers or very good rebuilds, and a new or well rebuilt secondary master cylinder and a good pressure bleed.

Okay, I'm ready. Blows some holes in this. :) :)
 
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There have been several questions/theories poised here that need to be clarified. I wish I had the complete answer to a permanent solution to this issue, but I think I can show why it is possible to get air into the system without having a leak of brake fluid.
The brake fluid seals, specifically those around the pistons that push the pads out to the rotors are a one way seal. They are designed so that as more pressure is applied, the seal against the piston becomes stronger. However, when the pressure is released, the strength of the seal becomes less. In many ways, it is like a check valve that allows fluid to flow in one direction, but not in the opposite direction. At the other end of the seal is the wiper portion. this is designed to keep crap from the portion of the piston that is exposed to atmosphere from entering the system. It also tends to keep air from entering the system, but as wear occurs on both the piston and the wiper it is possible for small amounts of air to find it's way into the closed hydraulic system.
Next, someone thought that bleeding the system would push all of the air trapped in the system out. In theory, this is true, but in reality most of our bleeding methods (i.e. squeezing the brake lever or pushing the brake pedal) are not capable of pushing enough brake fluid at one squeeze to completely evacuate an air bubble entrapped at a high point in the system. You may say that is why we lock the exit and release the brake then squeeze it again. You are right in that assumption, except during the reload of fluid, that little air bubble has made it's way back to the high point. If you want to see this action, just take your mighty vac and using a high loop pump it a few times and you can watch fluid being pulled from a cup pushing the air in the tube ahead of it. As it passed the high point, the air in the tube will continue to migrate to the top of the loop.
Finally, why does it only do it when it's hot. For the shudder to take place, there has to be a certain amount of compress ability of the brake fluid. Since the fluid itself is not compressible, it must have air in the system. A minuscule amount of air may go unnoticed in normal operation, but a large amount results in no pedal, or a soft peddle. Since you have a peddle you just assume there is no air in the system, but there actually is usually some. I'm thinking that on very hot days this small amount of air is expanding and making it's volume greater that it now gives room for the shudder to take place .

Hmmm, based on what I just wrote, I would think the fix would require new calipers or very good rebuilds, and a new or well rebuilt secondary master cylinder and a good pressure bleed.

Okay, I'm ready. Blows some holes in this. :) :)
I would think that the hydraulic pressure created by squeezing the brake pedal or hand lever would force fluid out of any wear spots on the caliper piston and seals. The hydraulic pressure is tremendously greater than the atmospheric pressure of air. But even if air could enter at the piston seal at the caliper because of wear of the seal and the piston I'm surprised that the issue isn't much more commonplace. The design of the piston seal is common not just to Goldwings, but most all vehicles with hydraulic braking systems, yet brake shudder is not a common problem.

I suggested that contamination of the pads is the cause of the brake shutter. The problem appeared after brake work was performed on the bike. It doesn't take very much grease, oil, brake fluid or other foreign material to contaminate a pad. I know from first hand experience that pad contamination can greatly affect the operation of the brakes, usually resulting in the pad(s) failing to release from the rotor when the brake is released. If you have ever had the experience of sliding on ice (I still love to do this at 67 years young) and hit small intermittent patches of dry ground you will better understand the effect. Heat can affect the degree of "sticky-ness" - similar to the effect heat has on oil (why most motor oils are specified to be multi-grade).

I hope the OP finds out the exact cause of the shudder so all of us may benefit from his experience, especially those who may develop a similar problem.
 

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I would think that the hydraulic pressure created by squeezing the brake pedal or hand lever would force fluid out of any wear spots on the caliper piston and seals. The hydraulic pressure is tremendously greater than the atmospheric pressure of air. But even if air could enter at the piston seal at the caliper because of wear of the seal and the piston I'm surprised that the issue isn't much more commonplace. The design of the piston seal is common not just to Goldwings, but most all vehicles with hydraulic braking systems, yet brake shudder is not a common problem.

I suggested that contamination of the pads is the cause of the brake shutter. The problem appeared after brake work was performed on the bike. It doesn't take very much grease, oil, brake fluid or other foreign material to contaminate a pad. I know from first hand experience that pad contamination can greatly affect the operation of the brakes, usually resulting in the pad(s) failing to release from the rotor when the brake is released. If you have ever had the experience of sliding on ice (I still love to do this at 67 years young) and hit small intermittent patches of dry ground you will better understand the effect. Heat can affect the degree of "sticky-ness" - similar to the effect heat has on oil (why most motor oils are specified to be multi-grade).

I hope the OP finds out the exact cause of the shudder so all of us may benefit from his experience, especially those who may develop a similar problem.
Just so you know, I actually changed rotors and installed new pads on my 03 hoping to solve the issue. It made zero difference. The only thing I ever had make a difference was the Rocky bleed, and that was a temporary fix. BTW, you are correct in that many vehicles have hydraulic brakes. Not many of them have linked brakes through a secondary master cylinder. Also, I have found what appears to be a permanent solution to the problem...........I bought a 2018. :) One other thing, I considered adding a speed bleed to the top of that high fitting. It could be done, but it was cheaper and more fun to buy the 18. :) :) :)
 

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The clue to the cause of the brake shudder is that it stops if you apply the front brake, or push harder on the rear brake lever. This is what leads me to think that the delay valve may be the cause. On light rear brake only application, the delay valve should be closed, and as you start to push harder the valve opens up and allows fluid to the front pistons, which then actuates the secondary master cylinder on the left brake caliper. My theory is that the delay valve is just on the edge of opening and is shuttering between open and closed, and then the secondary master cylinder gets pumped on and off, which amplifies the shudder 10 fold.


 
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