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Discussion Starter · #1 ·
I had the front right fork seal replaced. When I got my bike back the front brakes just sucked. I called the dealer and asked them if they knew what would be causing it and they said to bleed the brakes which I had already done. Of course they say they did nothing wrong. They were perfect before the bike went to the shop.

It works good the first time I use the brakes then goes back to the spongy feeling. Normally these brakes will throw you over the bars as you all know. Now they just suck and take forever to stop.

I've bleed them, replaced all the fluid with new, bleed the mc, and cleaned the pads and rotors. I've bleed the whole system at least 7 times, and like I said they work great the first time I pull the lever, after moving they go back to crap.

Any other suggestions?
 

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Wow, that's a lot of work. I'd be mad too. My best guess is air in the line. I had this problem with one bike (can't remember, but not a HM). One thing that worked quickly was to elevate the calipers above the MC. I used a piece of wire and hung them from a weight bench. Sandwich a flat piece of AL between the pads (approx. same thickness as rotor). Then bleed them as normal. The air wants to go up.

I wonder how this happened at the dealer, since they didn't need to crack the system to remove the forks?

Well, that's all I have. Good luck.
 

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Wow, that's a lot of work. I'd be mad too. My best guess is air in the line. I had this problem with one bike (can't remember, but not a HM). One thing that worked quickly was to elevate the calipers above the MC. I used a piece of wire and hung them from a weight bench. Sandwich a flat piece of AL between the pads (approx. same thickness as rotor). Then bleed them as normal. The air wants to go up.

I wonder how this happened at the dealer, since they didn't need to crack the system to remove the forks?

Well, that's all I have. Good luck.
I had to do the same thing once. Still had to do a full bleed about 2 more times before that last little bubble got out. Also try rotating or shaking the caliper lightly. I think that helped my bubble find its way out.


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Do you feel the lever is spongy for the initial pull or only the second or third application? Possibly a bad wheel bearing or sticking rotor button making the rotor push the pads into the caliper.
 

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If the pads got saturated in fork oil, they're toast. That doesn't explain how they work great on the first pull though...maybe oil in the pads is activated the heat?
Maybe rotor-hone the rotors and new pads are in order.
 

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One thing you can try is pounding on the bars to try to vibrate any bubbles up into the reservoir. Just an idea. It has worked for me in the past.

It sounds as if you are sucking air into the line when letting go of the lever. It could just be a coincidence with regards to timing. You might just have a bad seal.
 

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I had the front right fork seal replaced. When I got my bike back the front brakes just sucked. I called the dealer and asked them if they knew what would be causing it and they said to bleed the brakes which I had already done. Of course they say they did nothing wrong. They were perfect before the bike went to the shop.

It works good the first time I use the brakes then goes back to the spongy feeling. Normally these brakes will throw you over the bars as you all know. Now they just suck and take forever to stop.

I've bleed them, replaced all the fluid with new, bleed the mc, and cleaned the pads and rotors. I've bleed the whole system at least 7 times, and like I said they work great the first time I pull the lever, after moving they go back to crap.

Any other suggestions?
I think you still have a very small amount of air trapped in the master cyl pump itself right between the where the reservoir feeds into it and the port that is covered when the piston moves the slightest. The air doesn't get pumped down into the lines because there is so little actual fluid flow in the braking system. When you first pull the lever it feels fine but the air is sucked into the piston port. When you grab it again, the air is now in the port so it feels soft. To get it out, you must aggressively bleed the pump. Take your time and pump a LOT of fluid through it. The air may be so small that you won't even see it escape, but I think it is definitely in there...
 

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My first thought is that they didn't have to open the brake system when they did fork seals, but they very well could have gotten fluid on the calipers.. But that doesn't explain them working well for the first application - I'm interested in what you find.
 

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There may be some air trapped behind the pucks. Remove the MC cover and sponge up a little fluid, yank the calis, remove the pads and push all the pucks back in as far as they can go. Refit the pads/calipers and pump the pads back onto the disc and hope the lever stays firm. :)

There was another Hyper frt brake issue a while ago referred to as "pump up" but your issue sounds different. With the pump up issue, the brakes would work great first time or so, and then be hard to modulate, as the lever had to be pulled further to the grip before they started to bite. A number of owners felt the seals were too tight around the pucks and would pull them off the rotors too much, and so they lubed them with a rubber/silicone lube and that seemed to help keep the pucks on the rotor for consistent lever action. When your brakes go mushy, are the pads still riding on the rotor? i.e. you should hear a little hissss from the frt brakes when you walk the bike. Good luck. :)
 

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Discussion Starter · #11 ·
Do you feel the lever is spongy for the initial pull or only the second or third application? Possibly a bad wheel bearing or sticking rotor button making the rotor push the pads into the caliper.

The first pull they work great. After that they go spongy.

Gonna try tapping on the bars a little while bleeding the next time to see if I can get any more air to go up to the mc. I've been bleeding to calipers first then moving to the mc.
 
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