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Discussion Starter · #1 ·
I did a search and found this thread from 2007:

http://www.hondashadow.net/forum/72-technical-discussion/49857-front-brake-pulsing.html

It sounds almost identical to what I experienced today. Braking a slower speeds, all is well. Braking from higher speeds and the front end pulses, literally moving up and down as she slows.

The posters on the thread recommend
1) cleaning the brake assembly,
2) checking the rotor for warping
and, from another thread of the same era, ( http://www.hondashadow.net/forum/72...ront-brake-has-pulsing-grab-when-applied.html )
3) check that the caliper is mounted securely
4) check for a loose connection in the triple tree (though as a greenhorn I have not idea what that is...)

Is this the list, in an appropriate order, that I should be working through?
All has been well until today in which she spent more time in the sun. Could the heat play a factor and/or the brake fluid level? There's only the tiniest of bubbles in the reserve tank.

Anything else that might be likely I should look into?

Thanks. I'll be a grease monkey eventually. It would make my dad very proud...
 

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1999 Shadow 750 ACE VT750CD3 Modified
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Clean the brake assembly, make sure there is not dirt build up around the pistons and seals. Clean the pads and rotors, I'd use Lloyd's Brake Clean (Non-flammable), the bad for the ozone stuff, it is still the best, available at TSC Stores and probably elsewhere.

I would also drain and flush the brake fluid, bubbles are bad and may indicate moisture in the fluid, use the right Brake Fluid IIRC DOT4.
That brake fluid could be 12 years old!!
Get a helper for bleeding the brakes.

If this does not solve it then I would move on to the next stages, but I would expect the above is the cure.
 

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Rotors don't really warp too often; that's just a myth. 99.99999999% of the time shuddering or pulsing is due to uneven deposits being laid on the rotor.

That said, if you have a floating rotor the hats can get jammed full of crap; this prevents them from floating.

Most likely though, it's uneven deposits on the rotor.
 

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I'm not a brake expert so I cant reply to your issue but I will say that you have a SWEET looking bike! Like it!!!
 

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Discussion Starter · #5 ·
Thanks all. I'll get started today. With the kids off school as of this afternoon it's going to get tougher to get out. Guess I've got lots of time to get it going (stopping?) again.

... but I will say that you have a SWEET looking bike! Like it!!!
Back atcha! (though I've since taken off the windscreen and love. it.)>:)
 

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2001 Valkyrie I/S
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If the rotors were warped you would get a shimmy side to side when you used the brake. When you use your front brake your putting more load on the front suspension so the front of the bike moves down. I could just be a your decreasing and increasing the pressure as you slow or your fork oil is not right. Try using front and rear brakes together to see if that makes a difference.
 

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I'm not a brake expert so I cant reply to your issue but I will say that you have a SWEET looking bike! Like it!!!
Thanks all. I'll get started today. With the kids off school as of this afternoon it's going to get tougher to get out. Guess I've got lots of time to get it going (stopping?) again.



Back atcha! (though I've since taken off the windscreen and love. it.)>:)
Oh paleeze..... you guys and your black VLX's.:grin2:

I'm going with the deposit on the rotor, maybe a hard spot in the rotor? Do you see any shinier spots where the pads contact the rotor?
 

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Rotors don't really warp too often; that's just a myth. 99.99999999% of the time shuddering or pulsing is due to uneven deposits being laid on the rotor.

That said, if you have a floating rotor the hats can get jammed full of crap; this prevents them from floating.

Most likely though, it's uneven deposits on the rotor.
^^^this.

Also sometimes rotor problems are contributed to hardened spots on the rotor caused by water being splashed up on a hot rotor. Those spots will turn harder (almost heat treated) than the rest of it and as the rotors wear, the harder spots don't wear at the same rate causing high places in the rotor.
 

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If the rotors were warped you would get a shimmy side to side when you used the brake. When you use your front brake your putting more load on the front suspension so the front of the bike moves down. I could just be a your decreasing and increasing the pressure as you slow or your fork oil is not right. Try using front and rear brakes together to see if that makes a difference.
Meh, I'm not buying the whole shimmy side to side thing. On a car, maybe if both front rotors are warped, it could shimmy side to side but with one rotor on a bike, its just going to pulse.
 

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When was the last time you cleaned or detailed your bike?

You may have gotten something on the rotor.
Maybe some over-spray of wax or polish. Armor All?
If it only contacted one portion of the rotor, there would be a reduced friction coefficient on that part of the rotor.
Then it would appear to be "pulsing" as that part contacted the brake pads during braking.

Just thinking outside the box......
Good luck.
 

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Discussion Starter · #11 ·
Took the front caliper off this morning. Pads have lots of room for wear yet. Gave everything a lube and wiped down the rotor with brake cleaner...

Question: What colour SHOULD the brake fluid be? I checked the reservoir, which was a bit too full, and while it's still clear/transparent, there's a golden/amber tint to it. Should it be crystal clear like DOT3 (which is what I have for reference) or does it naturally have some colour to it?
 

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Discussion Starter · #12 ·
Also sometimes rotor problems are contributed to hardened spots on the rotor caused by water being splashed up on a hot rotor. Those spots will turn harder (almost heat treated) than the rest of it and as the rotors wear, the harder spots don't wear at the same rate causing high places in the rotor.
Uneven wear or build up of some sort/grease etc on the rotor be something that would wear off with use - as in I should find a safe location and do a lot of higher speed breaking? Or am I looking at a new rotor?

The clean up from this morning didn't do the trick so I'm on to the next step in the puzzle. Everything *looks* clean and even but I understand with rotors, looks can be deceiving.
 

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Took the front caliper off this morning. Pads have lots of room for wear yet. Gave everything a lube and wiped down the rotor with brake cleaner...

Question: What colour SHOULD the brake fluid be? I checked the reservoir, which was a bit too full, and while it's still clear/transparent, there's a golden/amber tint to it. Should it be crystal clear like DOT3 (which is what I have for reference) or does it naturally have some colour to it?
Should be clear, if it is an amber/golden color it needs to be changed. Be sure to cover anything with paint on it with plastic, brake fluid is a pretty decent paint remover...:surprise:
 

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I have seen many times on cars where someone has washed their car and then it sat for a few days and where the pads were sitting there is a perfect pattern of rust or black looking corrosion. So it can add an area of different friction. A couple of things you can do. The proper way to check for warp is with a dial indicator but not many people have one of those. If you take the caliper off and spread the pads see it they will retract easily back into the cylinder. If they do leave the caliper off and spin the front wheel and with 240 or 320 sandpaper polish the surfaces on the rotor. Look for obvious areas of rust or anything different. Then put the caliper back on and very gently squeeze the lever till the pads are barely touching. Spin the wheel and listen for definite rubbing areas that may be high spots. It is a crude way to find a warp.

I always sand the pad surface also and that may remove a grease blob or other contaminant. Clean it well when you are done.
 

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Discussion Starter · #16 ·
Yep. Warped rotor as confirmed by a friend who's a mechanic. I found a segment that still has remnants of the original factory hashing meaning it's been warped since installation. Not a factor when I gear down to stop but time to save my pesos (aka CDN$).

Opinion - is this a job I can do at home (assuming all appropriate tools on hand including torque wrench)? What factors do I need to consider before tackling this that wouldn't show up in the service manual?
 

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It would not be too hard for you . If you take off the front wheel it is only a matter of removing the bolts and replacing the rotor and torquing the bolts correctly. Clean the surfaces well with brake cleaner. If you don't buy new bolts put some blue lock-tite on them . If you want to try something first before you buy= With the wheel still on the bike you may be able to get to all the bolts. Take them out and spin the rotor 180 degrees and put blue lock-tite and reinstall the bolts. Torque properly. See if that helps the warp feel. Sometimes it can reposition and re-align the rotor. If not, you still can buy a rotor.
When doing brakes on a car the service manual would say to burnish the new pads= by going 35 MPH and do several moderate stops.
 
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