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Discussion Starter · #1 ·
Front brakes locked on '01 FLHRCI. Had to loosen bleeders to move bike. Scorched rotors!

Installed new polished rotors, chrome calipers, HD braided cables, ebc kevlar pads and DOT5 fluid. Ridden less than 200 miles.

Tested calipers when removing front wheel and noted that left side only 2 pistons moving, right side only 3. Disassembled calipers, all looks good. No chrome where it is not supposed to be, all pistons move freely and are round and not scored, bores look good, no scoring. No blockage in brake lines, master cylinder looks good, assembled correctly.

Brakes worked fine, no jerkiness, smooth. Front wheel spun freely. WHAT HAPPENED???

Headed to HD now to pick up new rebuild kit for calipers and master cylinder. Sure would like some insight as to what happened before it happens again.
 

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ORIGINAL DOOF BABE
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dmeals said:
Front brakes locked on '01 FLHRCI. Had to loosen bleeders to move bike. Scorched rotors!

Installed new polished rotors, chrome calipers, HD braided cables, ebc kevlar pads and DOT5 fluid. Ridden less than 200 miles.

Tested calipers when removing front wheel and noted that left side only 2 pistons moving, right side only 3. Disassembled calipers, all looks good. No chrome where it is not supposed to be, all pistons move freely and are round and not scored, bores look good, no scoring. No blockage in brake lines, master cylinder looks good, assembled correctly.

Brakes worked fine, no jerkiness, smooth. Front wheel spun freely. WHAT HAPPENED???

Headed to HD now to pick up new rebuild kit for calipers and master cylinder. Sure would like some insight as to what happened before it happens again.
I had that happen to me on my old Sporty - turns out the last guy who worked on it didn't use the proper DOT5 brake fluid...
 

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dmeals said:
DOT 5 is DOT 5, silicone brake fluid.
OK - what I meant was that he DIDN'T USE DOT5 fluid. Is that better? Yeesh...
 

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How did you determine the faulty piston movement? Hydrolics go to the easiest resistance first. Did you try blocking the working ones while leaving the other free?
Sqeeze the pads all the way in on both sides. Then pump them up and tie the brake lever in as tight as you can. Leave it over night. If there is a stubborn air bubble, that may dislodge it.
Hope it works for you. GL
 

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If loosening the bleeders unlocked the brakes, it sounds like the fluid was remaining under pressure after the brake lever was released. To me, that sounds like a problem with the master cylinder - maybe some kind of blockage?

John
 

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Sounds like the master cylinder return valve is not operating. Open the lid of the reservoir and watch surface of the fluid when pulling the brake lever. You should see a 'squirt' action when you release the lever, not much but noticeable. If not, mc is shot.
 

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ViennaHog said:
Sounds like the master cylinder return valve is not operating. Open the lid of the reservoir and watch surface of the fluid when pulling the brake lever. You should see a 'squirt' action when you release the lever, not much but noticeable. If not, mc is shot.
Thats what I told him on his other post in this forum. One's enough, guy. There's pleanty of people in here to get you going again.....;)
 

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I'm with Lady Godiva on this one. I had the exact same experience dmeals described and it was because I used the wrong fluid. :hmmm:
 

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Just to make sure nobody screws something up because of this thread:

The covers on the master cylinders of my '06 RK Classic, the owner's manual, and the service manual all say to use DOT4 brake fluid, not DOT5. In addition, the owner's manual says make sure not to mix DOT5 in with the DOT4.

On '06 touring models at least, I can say for sure to use only DOT4 brake fluid.
 

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capn_buzzcut said:
Just to make sure nobody screws something up because of this thread:

The covers on the master cylinders of my '06 RK Classic, the owner's manual, and the service manual all say to use DOT4 brake fluid, not DOT5. In addition, the owner's manual says make sure not to mix DOT5 in with the DOT4.

On '06 touring models at least, I can say for sure to use only DOT4 brake fluid.
AFAIK touring bikes changed in 2004 to DOT4. If nobody messed with the master cylinder or the lid, it indicate the right fluid type.
 

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Discussion Starter · #13 ·
'01 uses DOT 5.

Think I found the problem. Disassembled the master cylinder and found hard crusted debris in the deep end left over from the chrome prep/cleaning process. Scraped clean with dental pick, washed out with carb cleaner and finally blew out w/compressed air. Rebuild with new kit. Also replaced all rubber in caliper cylinders. Suspect the return/releif valve in mc was clogged with debris.

Filling and bleeding system this morning and hope it works properly. Will advise.

Thanks all for your input! Much appreciated!!
 

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Well done!! That had to be it, a clogged return passage. FYI, the MOCO went back to DOT 4 in 2004, with the anti-lock brakes available on police bikes, they have to use DOT 4. The DOT 5 sylicone fluid won't work with the ABS. Just wish it was feasable to retro my 2003. Well it CAN be done, but I ain't spendin' that kind of money!!!
 

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Geezer-Glide said:
Well done!! That had to be it, a clogged return passage. FYI, the MOCO went back to DOT 4 in 2004, with the anti-lock brakes available on police bikes, they have to use DOT 4. The DOT 5 sylicone fluid won't work with the ABS. Just wish it was feasable to retro my 2003. Well it CAN be done, but I ain't spendin' that kind of money!!!
Just wanted to chime in here, GG have you seen the ABS reservoir(?) on the Police bikes? The thing takes up about 1/3 of the R/S saddlebag. Might be worth it though to save the bacon.
edited for spelling.
 

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how about taking up about 1/2 of the right bag. thats the only down side to friggen abs. the moco is looking at a different unit that is smaller but who knows when and if they will.

the older bikes run dot5 alot of the newer are running dot 4 as stated before. dot5 silicone cannot be compressed in a abs system and with that soon to be a option on some bikes its easier to switch all so that they dont have 2 different fluids on the line
thats why the switch to dot4

that being said on newer bike read your master cylinder it will tell you what to use in it.
dot 4 is corrosive so be careful not to get in on anything paint especially
 

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RKJ said:
Just wanted to chime in here, GG have you seen the ABS reservoir(?) on the Police bikes? The thing takes up about 1/3 of the R/S saddlebag. Might be worth it though to save the bacon.
edited for spelling.
Be it a third or a half of the bag, it's too much. It'd be nice if they found a smaller unit, but good luck. BMW's is a huge unit too, but the Krauts in their engineering brillance mounted it under the frame!! Imagine, a lower CG! Whoda thunk it??? :hmmm:
 
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