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Discussion Starter #1
Hey all,

My front brake has always felt a little weak but I'm told that's just part of owning a VN900. But lately I've been noticing an oddity about the front brake control. It seems to be kind of "draggy". Have you ever had a car with a throttle cable (back when cars had throttle cables, heh) that ha stretched or corroded? It doesn't move in smooth flowing motions it kind of jerks from one spot to the next? Well that's what mine does, but only when applying the brake a little harder. I'm going to clean and lube the cable but wanted your opinions in if it could be anything else while I'm tinkering with it.

The other thing is, and this may just be a VN900 issue or it might be an issue with my bike. It takes a considerable amount of force to hold the bike on a hill with the front brake, but I don't have trouble stopping, even stopping hard / emergency stopping at speed. I'm a new rider so that might just be something that's normal but I wanted to make sure!

Thanks all,

John
 

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The 900's brakes won't win any awards for stopping power, but they should operate smoothly without jerking or catching.

You may need to tear the calipers down and give them a good cleaning, and change the fluid. (The brakes are not cable-operated, they're hydraulic.)

There are also some spots in the levers that need to be greased once in a while. Details are in the service manual.

Joe
 

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Discussion Starter #3
The 900's brakes won't win any awards for stopping power, but they should operate smoothly without jerking or catching.

You may need to tear the calipers down and give them a good cleaning, and change the fluid. (The brakes are not cable-operated, they're hydraulic.)

There are also some spots in the levers that need to be greased once in a while. Details are in the service manual.

Joe

It's not so much that the brakes are grabbing as the control itself is. I'll look into greasing that lever... That makes sense. That's probably it.

How about the difficulty holding on a hill? I mean you have to squeeze hard to keep the bike from rolling. Is that normal or is there an issue?
 

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It's not so much that the brakes are grabbing as the control itself is. I'll look into greasing that lever... That makes sense. That's probably it.

How about the difficulty holding on a hill? I mean you have to squeeze hard to keep the bike from rolling. Is that normal or is there an issue?
Have you bled the brakes recently and added new fluid? After a few thousand miles of stop 'n go, the fluid near the calipers can absorb a little extra heat and get "squishy", so that the longer the fluid is under pressure, the more it gives. Cars do it too, with the brake pedal slowly sinking until it bottoms out after a stop.

If that doesn't help, I'd take a deeper look.
 

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How about the difficulty holding on a hill? I mean you have to squeeze hard to keep the bike from rolling. Is that normal or is there an issue?
Doesn't sound normal to me. I suppose it depends on how steep the hill is, but I don't recall ever having trouble keeping my 900 from rolling while stopped.

When was the last time you inspected the brake pads? Maybe they're worn. Or maybe a fluid issue like Pretzel said.

Joe
 

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Same suggestion.... Do a brake bleed first, may fix both issues. Then next fix will be a caliper rebuild.
 

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Discussion Starter #7
I'll do the fluid. Pads are fine. They looked fine to me, and on top of that last week I had the safety inspection done for the year and the dealer told me they had about 60% left.

I played with it a bit and looked closer and I think the grabbing is a lube issue for the handle. There's a faint squeaking in the handle. I'll bleed the brakes, both front and rear. Easy enough right? Loosen the bleed screw, pump the brakes while replacing the fluid in the master cylinder? Continue until fresh fluid is consistently coming out of the bleed screw?

Is there anything I need to do to the master cylinder when I bleed the brakes? Any seals that I should replace, or anything like that? I've done a brake bleed on a car before, but never a bike.

Just while I'm at it... what would indicate I need a caliper rebuild? It's an '06 with only 15k miles (9k when I bought it in September). I don't know how it's been ridden before, but as long as I've been riding it it's been mostly highway (especially 55mph state highways with limited stopping). I live in a rural area, I don't use my brakes much. In fact, most of the time I can just downshift and coast and brake at the very end, so in other words, they aren't being used severely.

The odd thing is, even though it's been giving me trouble at a stop, when I had to make an emergency stop a while back (commercial truck pulled out into my lane head on) I was able to stop VERY quickly. I grabbed the front hard and hit the rear, locked up both but immediately let off the front enough to keep it from being locked up (I think I left the rear locked up, don't remember... it happened pretty fast LOL). So in other words, it had the braking power to handle that emergency stop (plus all of the low speed emergency stop practice I did). It just seems oddly weak at a dead stop. Pretzels suggestion about fluid break down makes the most sense, so that's what I'll do!

Any recommendations on fluid? Any particular fluid that might improve performance, or last longer? I've just always used whatever was on the shelf (or I had sitting around anyway) in my cars... but since these brakes aren't the best I'd like to use some good stuff. Plus, it seems like there is a lot less fluid in my bike than my car.... so it would seem that the fluid would break down quicker, so longer lasting fluid seems like a plus.

Hey thanks folks!

-John
 

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What made me think of a caliper rebuild was the comment on the brakes were grabbing (but not under hard braking). When the pistons are dirty or fluid is contaminated the pistons sticks (does not return smoothly), potentially causing the pads to grab when they should have retracted. Just a theory (and some experince with Mountain Bike brakes).

As for fluid stay with recommended brake fluid as they are not all the same. Different boiling points, and motorcycle brakes will run hotter than cars.
 

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Discussion Starter #9
What made me think of a caliper rebuild was the comment on the brakes were grabbing (but not under hard braking). When the pistons are dirty or fluid is contaminated the pistons sticks (does not return smoothly), potentially causing the pads to grab when they should have retracted. Just a theory (and some experince with Mountain Bike brakes).

As for fluid stay with recommended brake fluid as they are not all the same. Different boiling points, and motorcycle brakes will run hotter than cars.
No the brakes aren't grabbing (sorry, I did a poor job explaining this). Let me try it this way- there is resistance in spots as I pull the brake lever. So I cannot pull it in a smoth fluid motion, as I pull the brake (I.e. apply) it "grabs" making me have to pull it a bit harder. I believe that's due to a poorly lubed lever. Ive gotten caught in two spring showers now so I bet there may be some gunk or corrosion in there.
 

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No the brakes aren't grabbing (sorry, I did a poor job explaining this). Let me try it this way- there is resistance in spots as I pull the brake lever. So I cannot pull it in a smoth fluid motion, as I pull the brake (I.e. apply) it "grabs" making me have to pull it a bit harder. I believe that's due to a poorly lubed lever. Ive gotten caught in two spring showers now so I bet there may be some gunk or corrosion in there.
Okay, got it. A good cleaning and lube should fix that issue. I would still bleed the brakes for the other issue as you should be able to hold the bike on a hill with the front brake.
 

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Discussion Starter #11
Okay, got it. A good cleaning and lube should fix that issue. I would still bleed the brakes for the other issue as you should be able to hold the bike on a hill with the front brake.
What's the best way to do that? Best product/oil/grease to use? The service manual didn't detail the process (that I could see).

Thanks for all the help guys! Monday I'll do the bleed (if I can find a helper) with some DOT 4.

John
 

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No the brakes aren't grabbing (sorry, I did a poor job explaining this). Let me try it this way- there is resistance in spots as I pull the brake lever. So I cannot pull it in a smoth fluid motion, as I pull the brake (I.e. apply) it "grabs" making me have to pull it a bit harder. I believe that's due to a poorly lubed lever. Ive gotten caught in two spring showers now so I bet there may be some gunk or corrosion in there.
Mine does the same thing with the front brake! I think it is something in the cable or actual handle.
 

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Discussion Starter #13
Mine does the same thing with the front brake! I think it is something in the cable or actual handle.
There is no cable, it's hydraulic (dunno what I was thinking when I said that earlier). The lever just presses on a plunger in the master cylinder (box mounted on our handlebars) which in turn pushes hydraulic brake fluid into the pistons on the brake caliper, giving you tremendous mechanical advantage. So the issue on your bike and mine is probably that pivot point, which I'm going to lube up tonight (as well as a fluid change). We'll see how it all turns out!
 

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It's an '06 with only 15k miles (9k when I bought it in September).


Any recommendations on fluid? Any particular fluid that might improve performance, or last longer? I've just always used whatever was on the shelf (or I had sitting around anyway) in my cars... but since these brakes aren't the best I'd like to use some good stuff. Plus, it seems like there is a lot less fluid in my bike than my car.... so it would seem that the fluid would break down quicker, so longer lasting fluid seems like a plus.
If it has that many miles and the fluid has never been changed, I bet it will be nasty, especially the stuff in the caliper. I did mine at about 19k and it came out like used diesel oil. After you bleed, be carefully on the first ride. Those things are gonna grab if you use the same pressure, I locked up both tires the first time after bleed mine.

Personally I never use brake fluid out of a open container. Brake fluid is Hygroscopic Most are at least, so if it has been sitting it will absorb moisture which has a lower boiling point. Personally it is cheaper to just buy a new container then to rely on 'old' fluid. I like to use the old fluid to run my rubber hose into that way I don't have to suck up air.
 

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I just had my clutch lever break, it has been on since '97. What I found was that the bushing that the lever pivots on was worn severely and had a deep wear zone from use over the yrs. When I put on the new lever and new bushing I found that the clutch was considerably easier to operate. The same thing may be part of your brake and only taking it apart will tell. The clutch lever assy was spendy, about $50. I don't know if the bushing is available alone. Also, the slides that the movable part of the caliper rides on my be grungy and in need of clean and re lube. White lithium grease is what you would use to re lube them. Keep it out of the cylinders and such, only used on the metal to metal rubs. Moly would be a good grease for the lever bushing.
 

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The Kaw shop manual recommends rebuilding the caliper every other brake change..... so you should be OK at this time, since you are still on the first change out..... I just recently rebuilt my rear caliper due to a bent spring behind the pistons.... It was a really easy process to change out all the boots, O ring and dust seal, so if the lever fix doesn't do the trick, then your next step is to look at the rebuild.....
 

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What's the best way to do that? Best product/oil/grease to use?
I just had my clutch lever break, it has been on since '97. What I found was that the bushing that the lever pivots on was worn severely and had a deep wear zone from use over the yrs. When I put on the new lever and new bushing I found that the clutch was considerably easier to operate. The same thing may be part of your brake and only taking it apart will tell. The clutch lever assy was spendy, about $50. I don't know if the bushing is available alone. Also, the slides that the movable part of the caliper rides on my be grungy and in need of clean and re lube. White lithium grease is what you would use to re lube them. Keep it out of the cylinders and such, only used on the metal to metal rubs. Moly would be a good grease for the lever bushing.
+1 on the moly & lithium. Have used both when reassembling metal to metal parts. Holds up well.
 

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Discussion Starter #18
Did the bleed. Just got done riding about 30 miles. No need to lube the handle just the bleed fixed the issue. Stops much better now! Still feel like I need a lot of oomph to hold it on a steep hill but I guess that's because I'm used to vacuum assisted cager brakes.
 

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I have to second the full fluid change recommendation. Even though the fluid in the brake fluid reservoir on the handlebar may look good, the stuff farther down the line can be really nasty. In addition to bleeding the brake lines, I'd recommend flushing out the whole system and replacing ALL the brake fluid using brand new fluid from an unopened new container.

As for the caliper rebuild, it's not such a hard thing to do. The main thing is once you have it off, remove the pads and clean them using spray brake cleaner. Then spray down the whole caliper to get it all cleaned off. Next, disassemble it bt removing the screws that hold it together and separate the halves to expose the slider pins. Clean them off and apply a light coating of disc brake lube and reassemble. And yes I did say. Brake lube. You can get a. Small packet of it at most. Auto parts stores for about a dollar. It's a special grease designed for lubing the caliper sliders. Make sure the pistons slide in and out easily, too. Unless something has gotten in there and done some actual physical damage, you shouldn't need to buy any parts or rebuild kits. If you do this periodically, your brakes will perform well for many miles.
 

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Discussion Starter #20
I have to second the full fluid change recommendation. Even though the fluid in the brake fluid reservoir on the handlebar may look good, the stuff farther down the line can be really nasty. In addition to bleeding the brake lines, I'd recommend flushing out the whole system and replacing ALL the brake fluid using brand new fluid from an unopened new container.

As for the caliper rebuild, it's not such a hard thing to do. The main thing is once you have it off, remove the pads and clean them using spray brake cleaner. Then spray down the whole caliper to get it all cleaned off. Next, disassemble it bt removing the screws that hold it together and separate the halves to expose the slider pins. Clean them off and apply a light coating of disc brake lube and reassemble. And yes I did say. Brake lube. You can get a. Small packet of it at most. Auto parts stores for about a dollar. It's a special grease designed for lubing the caliper sliders. Make sure the pistons slide in and out easily, too. Unless something has gotten in there and done some actual physical damage, you shouldn't need to buy any parts or rebuild kits. If you do this periodically, your brakes will perform well for many miles.
You're late to the party bro! Just got done replacing the fluid. It was pretty nasty, must not have ever been done. I keep a little maintenance schedule on my computer so I've made brake fluid something to do on March 1st of each year (too easy and cheap not to do once a year and it'll keep things running smooth. I'll do the caliber rebuild soon but it seems to be performing fine right now. Definitely will do it next March.
 
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