Rear brake caliper

tomrom · 06-05-2018, 09:31 PM

Has anyone else had any issues with rear disc brakes? The caliper on my storm moves but it does't lock up the wheel. I can turn the wheel by hand when the brake is fully depressed. I did bleed through about 8 oz of fresh fluid to be sure there was no air and cleaned the rotor with brake cleaner.

zippy · 06-05-2018, 10:07 PM

I had the same problem on a Hawk. No matter how many times I bled the rear brake caliper it just did not make the pads grab the disk sufficiently. Finally I bought an item from eBay called a:

Motorcycle Car Clutch Brake Bleeder Hose One Way Valve Tube Bleeding Tool Kit

There are many eBay listings for this (just use the caption above in the eBay search bar) and I have posted a picture of the product. They are available for about 4 or 5 dollars.

When I bled the caliper with this tool apparently I got all of the air out of the line for the first time. It has worked perfectly ever since.

roundhouse · 06-05-2018, 10:09 PM

Thanks! I have had the same prob!.

tomrom · 06-06-2018, 07:40 AM

Have one on order and will give it a try. TY.

**JerryHawk250** · 06-06-2018, 08:01 AM

Just ordered one for $3.42 https://www.aliexpress.com/item/New-...d6a54c4dcvseby

Megadan · 06-06-2018, 09:35 AM

Also, fun tech tip.

Dismount the rear caliper and line clips, wedge something between the pads to keep them spaced apart - careful not to damage the pads. Hang the caliper from the grab rail with zip ties or similar. This will make the caliper the high point in the system and allow any remaining air to make its way to the caliper.

After bleeding, leave it in place and figure out a way to leave the rear brake lever compressed for a few hours and just let it sit. Tap on the master cylinder, brake line, and fittings, then give it another quick bleed.

If that doesn't get all of the air out of the system, then I don't know what will help you at that point, short of a pneumatic bleeder system.

tomrom · 06-09-2018, 06:04 PM

I spoke with Mr. Don over at Apsusa and he said it takes over 30 minutes with an electric pump to bleed one caliper.

All the internet videos I have watched conderning bleeding motorcycle brakes, the technician pumps the brake one time, holds down the lever and opens the bleeder valve, close the bleeder valve, let off the lever and repeat. With the exception on one video that was displaying check valve where the tech opened the valve and then pumped.

I have serviced my own automobile brakes for most of my life. Everyone who does this knows that in a car, one pumps the brake pedal several times, not just once, until the pedal is hard, and it's called 'having good pedal'. Then while someone is pressing on the brake, the technician opens the bleeder valve on the caliper and the pedal goes to the floor. Tightened the bleeder valve, release the pedal and repeat.

Well, Mr Don says to expect to pump the brake 100 times or more for each time you open the bleeder. I did this for over an hour and 1/2 with the check valve attached. and got no results. The check valve did not help me at all. I wish it did. I broke down and purchased a mitivac at Orielys. $52.00. It vacuumed out 10 or 12 cups of fluid over a few hours and does not seem to be letting up in the bubbles. The tool is made out of plastic and the handle popped off 5 or 6 times during use. Don't loose the pin if this happens to you.

Right now I am following Megadan's suggestion and have it suspended above the reservoir, opened, pedal held down. to be continued...

Megadan · 06-09-2018, 06:52 PM

There is always that chance that you have no air in the system, but the seal on the master cylinder piston may not be very good and is letting fluid past an thus reducing system pressure. Does the pedal stay firm when pumped up and pressed, or does it slowly start to lose pressure?

tomrom · 06-09-2018, 08:50 PM

One thing is for sure, while I waited for air to hopefully rise to the top, I had a chance to read the mitivac manual in regards to motorcycle brakes. It says to pump up the brake and open the bleeder valve while under a vacuum. Something I had not done prior and I was just running fluid through wasting time. Using this method I got clear fluid in a couple of pumping reps and had good hard pedal, and could no longer turn the wheel by hand. So, I put away most of my tools and decided to knock off for the night. Right before walking out of my garage, i did another quick test and already my pedal was spongy and had no stopping power at all.

tomrom · 06-11-2018, 11:00 PM

As it turned out, my actual problem had nothing to do with brake bleeding. The inside pad had become lodged in the metal housing part of the caliper that surrounds it. It's all fixed and back riding.

Megadan · 06-12-2018, 03:34 AM

Quote:

Originally Posted by tomrom

As it turned out, my actual problem had nothing to do with brake bleeding. The inside pad had become lodged in the metal housing part of the caliper that surrounds it. It's all fixed and back riding.

Good find. It's always the most stupid cause to the most frustrating issues.

Look on the bright side, at least you know the brakes are REALLY well bled.

06-05-2018, 09:31 PM	#1
tomrom Join Date: Apr 2018 Location: Vermont Posts: 56	Rear brake caliper Has anyone else had any issues with rear disc brakes? The caliper on my storm moves but it does't lock up the wheel. I can turn the wheel by hand when the brake is fully depressed. I did bleed through about 8 oz of fresh fluid to be sure there was no air and cleaned the rotor with brake cleaner.
	0

06-06-2018, 08:01 AM	#5
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,578	Just ordered one for $3.42 https://www.aliexpress.com/item/New-...d6a54c4dcvseby __________________ 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
	0

06-06-2018, 09:35 AM	#6
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,042	Also, fun tech tip. Dismount the rear caliper and line clips, wedge something between the pads to keep them spaced apart - careful not to damage the pads. Hang the caliper from the grab rail with zip ties or similar. This will make the caliper the high point in the system and allow any remaining air to make its way to the caliper. After bleeding, leave it in place and figure out a way to leave the rear brake lever compressed for a few hours and just let it sit. Tap on the master cylinder, brake line, and fittings, then give it another quick bleed. If that doesn't get all of the air out of the system, then I don't know what will help you at that point, short of a pneumatic bleeder system. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	0

06-09-2018, 06:52 PM	#8
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,042	There is always that chance that you have no air in the system, but the seal on the master cylinder piston may not be very good and is letting fluid past an thus reducing system pressure. Does the pedal stay firm when pumped up and pressed, or does it slowly start to lose pressure? __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	0

06-05-2018, 10:09 PM	#3
roundhouse Join Date: Sep 2017 Location: N Texas Posts: 706	Thanks! I have had the same prob!.
	0

06-06-2018, 07:40 AM	#4
tomrom Join Date: Apr 2018 Location: Vermont Posts: 56	Have one on order and will give it a try. TY.
	0

06-09-2018, 06:04 PM	#7
tomrom Join Date: Apr 2018 Location: Vermont Posts: 56	I spoke with Mr. Don over at Apsusa and he said it takes over 30 minutes with an electric pump to bleed one caliper. All the internet videos I have watched conderning bleeding motorcycle brakes, the technician pumps the brake one time, holds down the lever and opens the bleeder valve, close the bleeder valve, let off the lever and repeat. With the exception on one video that was displaying check valve where the tech opened the valve and then pumped. I have serviced my own automobile brakes for most of my life. Everyone who does this knows that in a car, one pumps the brake pedal several times, not just once, until the pedal is hard, and it's called 'having good pedal'. Then while someone is pressing on the brake, the technician opens the bleeder valve on the caliper and the pedal goes to the floor. Tightened the bleeder valve, release the pedal and repeat. Well, Mr Don says to expect to pump the brake 100 times or more for each time you open the bleeder. I did this for over an hour and 1/2 with the check valve attached. and got no results. The check valve did not help me at all. I wish it did. I broke down and purchased a mitivac at Orielys. $52.00. It vacuumed out 10 or 12 cups of fluid over a few hours and does not seem to be letting up in the bubbles. The tool is made out of plastic and the handle popped off 5 or 6 times during use. Don't loose the pin if this happens to you. Right now I am following Megadan's suggestion and have it suspended above the reservoir, opened, pedal held down. to be continued...
	0

06-09-2018, 08:50 PM	#9
tomrom Join Date: Apr 2018 Location: Vermont Posts: 56	One thing is for sure, while I waited for air to hopefully rise to the top, I had a chance to read the mitivac manual in regards to motorcycle brakes. It says to pump up the brake and open the bleeder valve while under a vacuum. Something I had not done prior and I was just running fluid through wasting time. Using this method I got clear fluid in a couple of pumping reps and had good hard pedal, and could no longer turn the wheel by hand. So, I put away most of my tools and decided to knock off for the night. Right before walking out of my garage, i did another quick test and already my pedal was spongy and had no stopping power at all.
	0

06-11-2018, 11:00 PM	#10
tomrom Join Date: Apr 2018 Location: Vermont Posts: 56	As it turned out, my actual problem had nothing to do with brake bleeding. The inside pad had become lodged in the metal housing part of the caliper that surrounds it. It's all fixed and back riding.
	2