Rear Brake Hung Up

stixx3969 · 02-20-2007, 05:58 PM

Hi gang.
Had a nice day in Mid Missouri so I drug the ol' Roketa out of the shed. Got her fired up and went for a little ride. A few blocks from the house after using the rear brake it hung up and started bogging me down but it didn't lock up. I limped back to the house slowly in first gear because that's all that would pull it. I didn't really overheat too bad but I need to know what to do now if it's still hung after everything cools down. I figure sitting all winter is the culprit and the piston is gooey. New Fluid? , Bleeding?
Ideas.

blimpman · 02-20-2007, 06:30 PM

Happened to me too. I just opened the bleed valve and let the pressure out... Been OK since then. I would recommend that the fluid be replaced with known good quality DOT 4 fluid. I have done this to my front brake and the rear brake is next.

ob1 · 02-20-2007, 06:33 PM

Seems like someone said the reservoir was overfilled. this reduced the area for the brake fluid to expand as it heated, forcing the brake caliper to absorb the expansion, dragging the brake.

msRandi · 02-20-2007, 06:39 PM

one check the vent and brake fluid, can,t be over full. open bleeder and move the piston back, close the bleeder and hit the brake. see if wheel speens? if the piston keeps sticking. you need to rebild or replace it.

stixx3969 · 02-20-2007, 10:15 PM

Thanx for the tips. It loosened up after I let it sit for a little while. Think I'll crack the bleeder and check the fluid. I think it'll be ok. Thanx again!

red2003 · 02-21-2007, 07:51 AM

Quote:

Originally Posted by ob1

Seems like someone said the reservoir was overfilled. this reduced the area for the brake fluid to expand as it heated, forcing the brake caliper to absorb the expansion, dragging the brake.

Yup, that's more then likely the culprit. All good advice. Let us know what you find out

.

fatboy250 · 03-01-2007, 09:59 AM

Ok, Dad and I have figured out the deal on this. If you look at the bottom of your rear break master cylinder (not the slave at the wheel) you will see where the armature pushing in has two linkages with a bolt and two nuts for adjustment. Well, even with the nuts in the lowest setting where the linkages are both resting on the top nut, the master cylinder armature is still being pushed into the master cylinder creating some pressure. So, you will need to permanantly remove the nut between the two linkages and shorten the bolt (a grinding wheel may work well) so that the two linkages are touching. This will allow the master cylinder armature to release all the way out. We believe it's not necessarily a design flaw, but more of where the weld ended up for the bracket that holds both the rear foot peg bracket and the master cylinder. If this bracket weld had been about 1/2" higher the master cylinder armature would be allowed to extend all the way out with the stock bolt and nuts adjustment. I will try to get a picture of this to show more when I do mine. Dad is in the middle of getting his taken care of. So far this has been the only "problem" that was not a result of hard riding. There's no dissatisfaction with these, but he and I are both relieved to finally figure this out.

Jason

liverchip · 03-01-2007, 11:03 AM

Good find there Jason!

mdsuave13 · 03-01-2007, 01:30 PM

any recommend a specific fluid? i used prestone dot 4 fluid.. it seems to be working fine, so far no braking issues whatsoever except for when my front caliper almost fell off because a bolt fell out while riding (managed to back track and find it in the road!)

ambassador · 03-01-2007, 02:07 PM

Prestone dot 4 here...

fatboy250 · 03-01-2007, 03:38 PM

Dot 3 or 4 is fine. I had 4 when I bled mine so that's what I replaced it with.

Yeah, VFRFlyer had his hang up twice when we were out a couple of weeks ago. The fix is pretty straight forward, but I figure 20-30min and mine should be done. I just have to set aside the time to do it. Kind of low priority since mine never hung up as much as Dad's did.

Jason

mdsuave13 · 03-01-2007, 05:14 PM

hey jason, how are your tires working out for you? you still like them?

you have the cheng shin's correct? i've been considering getting a spare set of wheels with a set of them so i can have street tires for commuting, and the knobbies for when i play on unpaved roads (even tho they are pretty terrible tires)

fatboy250 · 03-01-2007, 09:38 PM

Ride is fantastic. just don't expect to do any serious mud riding. They also have better side wall rigidity for cornering. These bikes will get down if you want to corner. I worn a pretty good place on my right shoe from when I touch from time to time (exit ramps)

cycleway4 · 03-07-2007, 02:23 PM

Hi Jason.........I did your fix to my rear master cylinder linkeage today....
I had ridden the bike around the property here short trips,..but went out on first road trip today...brake began to drag within a few minutes...
so came back and found the problem to be just as you say....no free play in the linkeage........................took out the jamb nut [in between]..all ok now............

fatboy250 · 03-07-2007, 02:52 PM

Yeah our bolt had to be shortened because the two linkages would not touch otherwise. Only the cotter pin in the top and the one nut at the bottom. Both ours are working great now and Dad is finally happy!

02-20-2007, 05:58 PM	#1
stixx3969 Join Date: Jul 2006 Posts: 146	Rear Brake Hung Up Hi gang. Had a nice day in Mid Missouri so I drug the ol' Roketa out of the shed. Got her fired up and went for a little ride. A few blocks from the house after using the rear brake it hung up and started bogging me down but it didn't lock up. I limped back to the house slowly in first gear because that's all that would pull it. I didn't really overheat too bad but I need to know what to do now if it's still hung after everything cools down. I figure sitting all winter is the culprit and the piston is gooey. New Fluid? , Bleeding? Ideas.
	0

02-20-2007, 06:30 PM	#2
blimpman Join Date: Sep 2006 Location: Cuyahoga Falls, Ohio Posts: 267	Happened to me too. I just opened the bleed valve and let the pressure out... Been OK since then. I would recommend that the fluid be replaced with known good quality DOT 4 fluid. I have done this to my front brake and the rear brake is next. __________________ The destination is merely a by-product of the journey. '06 KLR650 '06 XT225 '92 XT225 Serow ( MBD.... Multiple Bike Disease...)
	0

02-20-2007, 06:39 PM	#4
msRandi Join Date: Jan 2007 Location: Douglas, AZ Posts: 220	one check the vent and brake fluid, can,t be over full. open bleeder and move the piston back, close the bleeder and hit the brake. see if wheel speens? if the piston keeps sticking. you need to rebild or replace it. __________________ Love from the Arizona High Desert
	0

03-01-2007, 09:59 AM	#7
fatboy250 Join Date: Sep 2006 Location: COLUMBIA, SC Posts: 973	Ok, Dad and I have figured out the deal on this. If you look at the bottom of your rear break master cylinder (not the slave at the wheel) you will see where the armature pushing in has two linkages with a bolt and two nuts for adjustment. Well, even with the nuts in the lowest setting where the linkages are both resting on the top nut, the master cylinder armature is still being pushed into the master cylinder creating some pressure. So, you will need to permanantly remove the nut between the two linkages and shorten the bolt (a grinding wheel may work well) so that the two linkages are touching. This will allow the master cylinder armature to release all the way out. We believe it's not necessarily a design flaw, but more of where the weld ended up for the bracket that holds both the rear foot peg bracket and the master cylinder. If this bracket weld had been about 1/2" higher the master cylinder armature would be allowed to extend all the way out with the stock bolt and nuts adjustment. I will try to get a picture of this to show more when I do mine. Dad is in the middle of getting his taken care of. So far this has been the only "problem" that was not a result of hard riding. There's no dissatisfaction with these, but he and I are both relieved to finally figure this out. Jason __________________ 2008 Jonway MC-70-150 2007 Roketa DB-07B (RSM-200E) 2006 Roketa DB-07A (RSX-200E) 1995 Kawasaki Concours (ZG1000)
	0

03-01-2007, 11:03 AM	#8
liverchip Join Date: Nov 2006 Location: Mystery Spot Posts: 1,223	Good find there Jason! __________________ 2009 XR650L Big Red Pig Tusk bar risers 2007 X-Moto(Jetmoto) GY250 --mods--- 15/40 sprockets UNI Pod Filter 2007 Shineray TMS 200XYi--Betsy Betsy Mods:______________________ Acerbis DHH headlight FMF Powercore pipe Uni Pod Filter
	0

02-20-2007, 06:33 PM	#3
ob1 Join Date: Jul 2006 Posts: 499	Seems like someone said the reservoir was overfilled. this reduced the area for the brake fluid to expand as it heated, forcing the brake caliper to absorb the expansion, dragging the brake.
	0

02-20-2007, 10:15 PM	#5
stixx3969 Join Date: Jul 2006 Posts: 146	Thanx for the tips. It loosened up after I let it sit for a little while. Think I'll crack the bleeder and check the fluid. I think it'll be ok. Thanx again!
	0

03-01-2007, 01:30 PM	#9
mdsuave13 Join Date: Jan 2007 Location: ellicott city, Maryland Posts: 857	any recommend a specific fluid? i used prestone dot 4 fluid.. it seems to be working fine, so far no braking issues whatsoever except for when my front caliper almost fell off because a bolt fell out while riding (managed to back track and find it in the road!) __________________ My name is Justin, my friends call me Stix. 2008 Kawasaki KLR650 Candy Lime Green ______________________________ I am the official China bike registration Guru For the State of Maryland..... HA.
	0

03-01-2007, 02:07 PM	#10
ambassador Join Date: Jan 2007 Location: Bradenton, Florida Posts: 1,200	Prestone dot 4 here...
	0

03-01-2007, 03:38 PM	#11
fatboy250 Join Date: Sep 2006 Location: COLUMBIA, SC Posts: 973	Dot 3 or 4 is fine. I had 4 when I bled mine so that's what I replaced it with. Yeah, VFRFlyer had his hang up twice when we were out a couple of weeks ago. The fix is pretty straight forward, but I figure 20-30min and mine should be done. I just have to set aside the time to do it. Kind of low priority since mine never hung up as much as Dad's did. Jason __________________ 2008 Jonway MC-70-150 2007 Roketa DB-07B (RSM-200E) 2006 Roketa DB-07A (RSX-200E) 1995 Kawasaki Concours (ZG1000)
	0

03-01-2007, 05:14 PM	#12
mdsuave13 Join Date: Jan 2007 Location: ellicott city, Maryland Posts: 857	hey jason, how are your tires working out for you? you still like them? you have the cheng shin's correct? i've been considering getting a spare set of wheels with a set of them so i can have street tires for commuting, and the knobbies for when i play on unpaved roads (even tho they are pretty terrible tires) __________________ My name is Justin, my friends call me Stix. 2008 Kawasaki KLR650 Candy Lime Green ______________________________ I am the official China bike registration Guru For the State of Maryland..... HA.
	0

03-01-2007, 09:38 PM	#13
fatboy250 Join Date: Sep 2006 Location: COLUMBIA, SC Posts: 973	Ride is fantastic. just don't expect to do any serious mud riding. They also have better side wall rigidity for cornering. These bikes will get down if you want to corner. I worn a pretty good place on my right shoe from when I touch from time to time (exit ramps) __________________ 2008 Jonway MC-70-150 2007 Roketa DB-07B (RSM-200E) 2006 Roketa DB-07A (RSX-200E) 1995 Kawasaki Concours (ZG1000)
	0

03-07-2007, 02:23 PM	#14
cycleway4 Join Date: Feb 2007 Location: Virginia Posts: 269	Hi Jason.........I did your fix to my rear master cylinder linkeage today.... I had ridden the bike around the property here short trips,..but went out on first road trip today...brake began to drag within a few minutes... so came back and found the problem to be just as you say....no free play in the linkeage........................took out the jamb nut [in between]..all ok now............ __________________ <div>Steve 2006 Roketa DB-07A/RSX-200E 2008 Roketa 250 Scooter 2019 Brozz 250
	0

03-07-2007, 02:52 PM	#15
fatboy250 Join Date: Sep 2006 Location: COLUMBIA, SC Posts: 973	Yeah our bolt had to be shortened because the two linkages would not touch otherwise. Only the cotter pin in the top and the one nut at the bottom. Both ours are working great now and Dad is finally happy! __________________ 2008 Jonway MC-70-150 2007 Roketa DB-07B (RSM-200E) 2006 Roketa DB-07A (RSX-200E) 1995 Kawasaki Concours (ZG1000)
	0