Brake lever flop

ChipToothy · 03-24-2020, 10:25 PM

Any tips on getting the rear brake lever to engage? I changed a flat and when I got everything back together the brake lever just bottoms out instead of engaging the pads. I took the caliper off the disk a few times, wiggled the pads, cleaned it a little and still nothing. I then tried replacing the fluid twice and still nothing. I’m guessing the problem is inside the bronze painted device.

This happened last year or the year before exact same scenario but it fixed itself on the second day. This time I’m not getting so lucky. It has something to do with being as simple as removing the 2 caliper bolts to get the wheel off. I feel like there’s a plunger in there or something that needs to drop. The brake lever pin is just sitting loose inside and hitting what sounds like metal.

ChipToothy · 03-24-2020, 10:28 PM

Forgot my pic

franque · 03-25-2020, 07:56 AM

Check your fluid level, make sure you have some in it, you could have nicked the piston seal when you were putting the brake back on. Otherwise, everything is bolted up normally? You didn't have to force anything?

ChipToothy · 03-25-2020, 08:18 AM

It was already full, I drained and refilled it twice just trying to get lucky. Literally all I did was remove the 2 bolts that hold the caliper on to get the flat tire off.

ChipToothy · 03-25-2020, 09:17 AM

A feller just looked it over and thinks it’s the master cylinder stuck. We couldn’t get the nut loose to try bleeding it.

**JerryHawk250** · 03-25-2020, 09:22 AM

You will probably need to adjust the linkage. It may not be returning far enough to pump the fluid. I've had that happen once and brake was locked up because it didn't return far enough to release the pressure.

ChipToothy · 03-25-2020, 10:55 AM

Quote:

Originally Posted by JerryHawk250

You will probably need to adjust the linkage. It may not be returning far enough to pump the fluid. I've had that happen once and brake was locked up because it didn't return far enough to release the pressure.

We finally got the nut loose and did a tighten-loosen bleed process 3-4 times. I then held a can of wd40 upside down and sprayed up into where the piston goes thinking maybe it was just dirty up under the boot. No luck yet.

ChipToothy · 03-25-2020, 06:04 PM

Alright, I removed everything, washed and rinsed it all, reassembled and filled the fluid. Still nothing. While the cylinder was open I could easily push the plunger down from the top with a pin. From underneath where the foot lever pin presses up in to it there was still no movement.

Im out of ideas.

ChipToothy · 03-26-2020, 08:45 PM

To the point now where I got the cylinder pumping fluid but not enough to move the pads. I’ve bled it through the nipple and caliper line a dozen times each but it won’t build any high pressures.

franque · 03-27-2020, 05:49 AM

I'd disassemble everything and blow air through all the holes. Even take the caliper apart and clean it out. Did it look like it was leaking anywhere, before you did anything?

2LZ · 03-27-2020, 12:39 PM

Yep, I'd take it all back apart again and look everything over. It worked before it was disassembled, correct? I wonder if you have a pad cocked on the caliper or something?
In my mind, it seems the issue would be at the caliper because that what was disassembled to begin with. All the axle spacers in correctly?

ChipToothy · 03-27-2020, 07:14 PM

I did a reverse bleed twice today. Zero bubbles came up in the reservoir.

Everything was working 100% before I changed the flat tire. With the brake caliper all I did was take out the two bolts that hold it to the bike. Replaced the tube and put it back together and it hasn’t worked since. One time I did get the pads to close together by doing multiple repeated pushes on the brake pedal and touch themselves when everything was taken apart during troubleshooting.

It’s had a full bottle of brake fluid pump through it two different directions, I soaked and clean the master cylinder like a boss, the calipers been removed and put back on probably a dozen times. I looked on CSC at the part and it’s 47 something dollars with shipping for a new master cylinder. I have no guarantee of course if that will fix the problem.

China Rider 27 · 03-27-2020, 07:27 PM

Have you isolated it to the master? Maybe disconnect the brake hose from the caliper, tie it upright and see if the Master pumps any fluid.

ChipToothy · 03-27-2020, 10:08 PM

Quote:

Originally Posted by China Rider 27

Have you isolated it to the master? Maybe disconnect the brake hose from the caliper, tie it upright and see if the Master pumps any fluid.

I’ve got it narrowed down to the caliper. It will close down the pads but not retract itself. I smeared everything I could get to with my pinky in grease and forced it open and closed over and over. It just won’t retract anymore. I assume it’s corroded inside the caliper mech.

China Rider 27 · 03-27-2020, 10:33 PM

Good to hear, you got it narrowed down, that is half the battle. Sounds like one of two things going on either the physical or hydraulic. If it is mechanical then you should be able to remove the line and see no improvement. If hydraulic when you remove the line it should release.

03-24-2020, 10:25 PM	#1
ChipToothy Join Date: Apr 2018 Posts: 819	Brake lever flop Any tips on getting the rear brake lever to engage? I changed a flat and when I got everything back together the brake lever just bottoms out instead of engaging the pads. I took the caliper off the disk a few times, wiggled the pads, cleaned it a little and still nothing. I then tried replacing the fluid twice and still nothing. I’m guessing the problem is inside the bronze painted device. This happened last year or the year before exact same scenario but it fixed itself on the second day. This time I’m not getting so lucky. It has something to do with being as simple as removing the 2 caliper bolts to get the wheel off. I feel like there’s a plunger in there or something that needs to drop. The brake lever pin is just sitting loose inside and hitting what sounds like metal. __________________ Bashan Storm: Ebay steel exhaust wrapped, folding shift lever, seat mod, vm26 carb, air pod, dual led scrambler headlamps, windshield mod, led brake/tail light, secondary led brake light (swingarm), Ebay 295mm rear shock, back up CDI (racing unknown), oil cooler, digital gauge cluster,
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03-25-2020, 08:18 AM	#4
ChipToothy Join Date: Apr 2018 Posts: 819	It was already full, I drained and refilled it twice just trying to get lucky. Literally all I did was remove the 2 bolts that hold the caliper on to get the flat tire off. __________________ Bashan Storm: Ebay steel exhaust wrapped, folding shift lever, seat mod, vm26 carb, air pod, dual led scrambler headlamps, windshield mod, led brake/tail light, secondary led brake light (swingarm), Ebay 295mm rear shock, back up CDI (racing unknown), oil cooler, digital gauge cluster,
	0

03-25-2020, 09:17 AM	#5
ChipToothy Join Date: Apr 2018 Posts: 819	A feller just looked it over and thinks it’s the master cylinder stuck. We couldn’t get the nut loose to try bleeding it. __________________ Bashan Storm: Ebay steel exhaust wrapped, folding shift lever, seat mod, vm26 carb, air pod, dual led scrambler headlamps, windshield mod, led brake/tail light, secondary led brake light (swingarm), Ebay 295mm rear shock, back up CDI (racing unknown), oil cooler, digital gauge cluster,
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03-25-2020, 09:22 AM	#6
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,562	You will probably need to adjust the linkage. It may not be returning far enough to pump the fluid. I've had that happen once and brake was locked up because it didn't return far enough to release the pressure. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
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03-25-2020, 06:04 PM	#8
ChipToothy Join Date: Apr 2018 Posts: 819	Alright, I removed everything, washed and rinsed it all, reassembled and filled the fluid. Still nothing. While the cylinder was open I could easily push the plunger down from the top with a pin. From underneath where the foot lever pin presses up in to it there was still no movement. Im out of ideas. __________________ Bashan Storm: Ebay steel exhaust wrapped, folding shift lever, seat mod, vm26 carb, air pod, dual led scrambler headlamps, windshield mod, led brake/tail light, secondary led brake light (swingarm), Ebay 295mm rear shock, back up CDI (racing unknown), oil cooler, digital gauge cluster,
	0

03-25-2020, 07:56 AM	#3
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	Check your fluid level, make sure you have some in it, you could have nicked the piston seal when you were putting the brake back on. Otherwise, everything is bolted up normally? You didn't have to force anything?
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03-26-2020, 08:45 PM	#9
ChipToothy Join Date: Apr 2018 Posts: 819	To the point now where I got the cylinder pumping fluid but not enough to move the pads. I’ve bled it through the nipple and caliper line a dozen times each but it won’t build any high pressures. __________________ Bashan Storm: Ebay steel exhaust wrapped, folding shift lever, seat mod, vm26 carb, air pod, dual led scrambler headlamps, windshield mod, led brake/tail light, secondary led brake light (swingarm), Ebay 295mm rear shock, back up CDI (racing unknown), oil cooler, digital gauge cluster,
	0

03-27-2020, 05:49 AM	#10
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	I'd disassemble everything and blow air through all the holes. Even take the caliper apart and clean it out. Did it look like it was leaking anywhere, before you did anything?
	1

03-27-2020, 12:39 PM	#11
2LZ Join Date: Mar 2010 Location: Volcano, Ca Posts: 7,092	Yep, I'd take it all back apart again and look everything over. It worked before it was disassembled, correct? I wonder if you have a pad cocked on the caliper or something? In my mind, it seems the issue would be at the caliper because that what was disassembled to begin with. All the axle spacers in correctly? __________________ "Light a fire for a man, and you heat him for a day. Light a man on fire, and you heat him for the rest of his life." 2007 Suzuki DRZ400S (SM convert) 2009 Q Link XP 200 1967 BSA B25 250cc Starfire 2022 Royal Enfield Interceptor 650 2023 Royal Enfield Scram 411 1948 Royal Enfield Model G 350
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03-27-2020, 07:14 PM	#12
ChipToothy Join Date: Apr 2018 Posts: 819	I did a reverse bleed twice today. Zero bubbles came up in the reservoir. Everything was working 100% before I changed the flat tire. With the brake caliper all I did was take out the two bolts that hold it to the bike. Replaced the tube and put it back together and it hasn’t worked since. One time I did get the pads to close together by doing multiple repeated pushes on the brake pedal and touch themselves when everything was taken apart during troubleshooting. It’s had a full bottle of brake fluid pump through it two different directions, I soaked and clean the master cylinder like a boss, the calipers been removed and put back on probably a dozen times. I looked on CSC at the part and it’s 47 something dollars with shipping for a new master cylinder. I have no guarantee of course if that will fix the problem. __________________ Bashan Storm: Ebay steel exhaust wrapped, folding shift lever, seat mod, vm26 carb, air pod, dual led scrambler headlamps, windshield mod, led brake/tail light, secondary led brake light (swingarm), Ebay 295mm rear shock, back up CDI (racing unknown), oil cooler, digital gauge cluster,
	0

03-27-2020, 07:27 PM	#13
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Have you isolated it to the master? Maybe disconnect the brake hose from the caliper, tie it upright and see if the Master pumps any fluid.
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03-27-2020, 10:33 PM	#15
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Good to hear, you got it narrowed down, that is half the battle. Sounds like one of two things going on either the physical or hydraulic. If it is mechanical then you should be able to remove the line and see no improvement. If hydraulic when you remove the line it should release.
	0