scat2me Posted October 23, 2020 Share Posted October 23, 2020 I just changed from Galfer SS brake lines to Core Moto SS lines. I needed a longer front line so I decided to get a complete set. I had no problems with the brakes. The bike has 2600 miles and the pads are 1 year old with 1100 miles. I do not ride hard. I bled the lines completely removed the Galfer, installed the Core moto and filled up with new dot4 Bel Ray Fluid. I wasn't getting any pressure in the lines. I took the advice of a member here and bottom filled the calipers . The font brakes are fine now. I did the same with the rear. I also removed the rear caliper, cleaned it lubed the pin and put everything back together. after I filled the rear brake and bled it I felt some pressure in the pedal. I spun the rear wheel and it stopped with the pedal. As soon as i rode around the Cul de sac there was no pressure or rear brakes at ALL. There are no leaks and again there was no issue before I changed the lines. Any ideas? Can the rear pedal be adjusted? The rear line is the exact same length as the original. The problem is no pressure. Link to comment Share on other sites More sharing options...
Premium Member DewMan Posted October 24, 2020 Premium Member Share Posted October 24, 2020 After you returned from your cul de sac run... did you spin the rear tire again and check to see if it stopped as it did before? If it does, it sounds like you may still have air in the line/master cylinder. If it doesn't and you confirm there are no leaks I'd say you have an issue with the master cylinder Good luck resolving your issue. DewMan Just shut up and ride. Link to comment Share on other sites More sharing options...
scat2me Posted October 24, 2020 Author Share Posted October 24, 2020 Thanks Ill try that tomorrow. Its to late now.. Link to comment Share on other sites More sharing options...
mossrider Posted October 24, 2020 Share Posted October 24, 2020 If it's at all similarly routed as this one, there's a very good chance there is air trapped in the rear master. Try bleeding it at the front of the line by cracking the fitting 2 or 3 times (use a wadded up towel to protect the area from brake fluid) then again at the rear caliper as usual. Link to comment Share on other sites More sharing options...
klx678 Posted October 24, 2020 Share Posted October 24, 2020 If you are near a Harbor Freight or similar store (discount tools) you can get a vacuum bleeder for around $30 or so, best money I ever spent. Vacuum bleed brake lines in a couple minutes. Light vacuum to avoid sucking air in at the fitting or draining the reservoir too fast. I did the rear brake on a Zephyr 550 after installing a new line in about 3 minutes. Same with the front. Crazy fast. Again, going low enough vacuum so as to not suck air past seals (they're made to seal directionally) or around the bleeder fitting (making it seem like there is more air in the system when there may not be). I've wondered if I could do it with a pressure feed forcing fluid in from the caliper end, if that would work even better. Link to comment Share on other sites More sharing options...
scat2me Posted October 24, 2020 Author Share Posted October 24, 2020 Thanks...it raining now so cant do anything. Before it started raining I saw that the caliper would not move at all its as if it were frozen on the disc. It did move freely yesterday after reassembly. I have a feeling the piston is stuck and doesn't return to the open position after the initial closure Link to comment Share on other sites More sharing options...
scat2me Posted October 24, 2020 Author Share Posted October 24, 2020 I got the vacuum bleeder. Bled the system. Removed the caliper cleaned it again verified the piston works properly and ordered a new master cylinder. Link to comment Share on other sites More sharing options...
Premium Member DewMan Posted October 25, 2020 Premium Member Share Posted October 25, 2020 3 hours ago, scat2me said: I got the vacuum bleeder. Bled the system. Removed the caliper cleaned it again verified the piston works properly and ordered a new master cylinder. So after you vacuum bled the system, you still had no brakes? How did you verify that the piston works properly? DewMan Just shut up and ride. Link to comment Share on other sites More sharing options...
scat2me Posted October 25, 2020 Author Share Posted October 25, 2020 I removed the caliper. I cleaned it completely (again) with brake fluid. I attached one of the old ss galfer lines and capped it off at the open end. I opened the bleeder valve and pressed the piston back into the caliper. I took a clean syringe with a hose and attached it the the bleeder valve. I pressed the syringe to blow air in the system. The piston came out and then receded the required amount. I decided that it is most likely the master cylinder. I dont have the time or energy to rebuild it. for the difference of$30.00 bucks I just ordered a new one. Link to comment Share on other sites More sharing options...
Lone Wolf Posted October 25, 2020 Share Posted October 25, 2020 (edited) On 10/23/2020 at 4:28 PM, scat2me said: The bike has 2600 miles and the pads are 1 year old with 1100 miles. ...I changed the lines. ...The problem is no pressure. The bike is virtually new with that mileage. No need to replace master cylinder. In addition to the vacuum bleeding I would manually move the brake pedal / lever, open the bleed screw, close the bleed screw, push the pedal (old school). That will ensure the master cylinder is bled and actually doing it's job as you bleed. Of course you put a clear tube on the brake nipple to direct the fluid into a jar, and if you put some grease on the nipple and the bleed screw threads you eliminate the bubbles and you can see what air is actually being pushed out of the lines (as opposed to sucking through the dry threads and dry connections) You can use a dedicated brake grease (like AGS Sil-Glyde Silicone Brake Lubricant) but plain old wheel bearing grease will stop the bubbles (external to the brake system on the nipple threads, it's not like a piston or caliper pin). If you watch videos of vacuum bleeding most people have bubble city. All of that stops if you pull the bleed nipple out, apply grease to threads, put back in hand-tight, put on a 6 point wrench, lube the end of nipple, put on clear tube to vacuum bleeder or jar for old school bleeding. Edited October 25, 2020 by Lone Wolf Link to comment Share on other sites More sharing options...
scat2me Posted October 25, 2020 Author Share Posted October 25, 2020 I did pump the brake pedal after the vacuum bleed. I was never able to get any resistance. I spoke to a mechanic about this. He feels teh piston in the cylinder may be either jammed or contaminated by something. Link to comment Share on other sites More sharing options...
Lone Wolf Posted October 25, 2020 Share Posted October 25, 2020 (edited) I see. Wow that is unusual for such a new part. Was there any fluid movement when you pumped the brake pedal (old school brake bleed). Did it pump fluid out into a jar - or just nothing? I understand no resistance, just curious if any hydraulic movement of fluid at all. Sounds like it lost it's prime somehow. "He feels the piston in the cylinder may be either jammed or contaminated by something" - Yeah but the change occurred immediately after changing the brake lines. He is wrong about the cylinder being jammed or contaminated. It lost it's prime somehow and is pushing air. You may want to try this How to: bleeding your brakes - prime the master cylinder - CBR Forum - Enthusiast forums for Honda CBR Owners How-To: Mechanical - How to: bleeding your brakes - prime the master cylinder - This problem comes up when you try to flush... Edited October 25, 2020 by Lone Wolf Link to comment Share on other sites More sharing options...
scat2me Posted October 25, 2020 Author Share Posted October 25, 2020 Yes I was able to pump fluid out. It just never built up pressure. After I had vacuumed out all of the fluid, I reversed filled the system from the bottom. The fluid went all the way up to the reservoir. I capped the reservoir and bled the system from the bottom by the tried and true ( pump the brake pedal, hold it down open the bleeder, close the bleeder and repeat. The pedal never built up any pressure to speak of. I went though 2 reservoirs of fluid, minimal bubbles. Now I did notice that the bleeder valve does not seem to be sealing completely. When I open it slightly it does bleed however I am noticing some fluid at the base. I am going to try the grease that you suggested and see if that makes a difference. Link to comment Share on other sites More sharing options...
scat2me Posted October 25, 2020 Author Share Posted October 25, 2020 23 minutes ago, Lone Wolf said: I see. Wow that is unusual for such a new part. Was there any fluid movement when you pumped the brake pedal (old school brake bleed). Did it pump fluid out into a jar - or just nothing? I understand no resistance, just curious if any hydraulic movement of fluid at all. Sounds like it lost it's prime somehow. "He feels the piston in the cylinder may be either jammed or contaminated by something" - Yeah but the change occurred immediately after changing the brake lines. He is wrong about the cylinder being jammed or contaminated. It lost it's prime somehow and is pushing air. You may want to try this How to: bleeding your brakes - prime the master cylinder - CBR Forum - Enthusiast forums for Honda CBR Owners How-To: Mechanical - How to: bleeding your brakes - prime the master cylinder - This problem comes up when you try to flush... If that is the case what do I do to get it primed? Link to comment Share on other sites More sharing options...
Lone Wolf Posted October 25, 2020 Share Posted October 25, 2020 3 minutes ago, scat2me said: If that is the case what do I do to get it primed? Read the thread on that link. This would apply to front or rear. He says to- 1. Loosen the banjo bolt connecting the brake line to the master cylinder. 2. remove the banjo bolt from the cylinder. 3. pour fresh brake fluid into the reservoir. 4. put your finger over the hole where the banjo was attached, effectively covering the opening. 5. pump the lever slowly. you will feel pressure on your finger every time you pump. 6. allow the fluid escape past your finger, but keep enough pressure on the opening as to not let any air back in. 7. when you feel that no more air is coming from the cylinder and only brake fluid, grab the brake line by the head of the banjo bolt and quickly release your finger and thread in the bolt all the way in. 8. tighten the banjo bolt to the specified torque. Then go on to bleed the brakes as you would normally. Link to comment Share on other sites More sharing options...
scat2me Posted October 25, 2020 Author Share Posted October 25, 2020 ok ill give it a shot. thanks Link to comment Share on other sites More sharing options...
scat2me Posted October 29, 2020 Author Share Posted October 29, 2020 (edited) Well after removing and cleaning everything related to the rear brake. I replaced the rear caliper bleeder nut, primed the master cylinder and still NO PRESSURE from the peddle. After a few choice words I took the new Core Moto SS line off the rear replaced it with the Galfer line and bled the system. I was able to get pressure fairly quick. The only issue is that although the pads are new (1000 miles) I have to really press hard to get the bike to stop. The system is bled but the peddle goes far to low. So now what ? To the dealer ? Or are there adjustments? Edited October 29, 2020 by scat2me Link to comment Share on other sites More sharing options...
mossrider Posted October 29, 2020 Share Posted October 29, 2020 With all due respect, you still have air in there someplace. I know it seems impossible and you may doubt me but I've bled thousands of them. It's a simple hydraulic system; a master (w/attached resivoir ), a line and a caliper. It worked when you messed with it and it doesn't now, unless you damaged something (highly doubtful), it has air in it. This is confirmed by your mention that you now have partial pedal. The rear usually includes a line loop or bow to allow for swingarm movement which can be very difficult to bleed completely. Take the rear caliper off. Find something to place between the pads that replicates the brake disc thickness. Now re-bleed the system but do it first holding the caliper as high as practical above the master/pedal, using both the bleeder valve and the banjo and do both ends, caliper and master. Then redo it but this time holding the caliper straight below the master, again using the banjo. Guaranteed to work. Trust me. Some of these can drive you insane. Patience and systematic perseverance. 1 Link to comment Share on other sites More sharing options...
scat2me Posted October 30, 2020 Author Share Posted October 30, 2020 I am getting pressure where I wasn't before. The line has no air or bubbles. The bike brakes but not as firmly as I think it should. I'm not sure I follow what you are describing. When I changed the lines from the OEM rubber to the Galfer SS lines there was no issue at all. I don't understand bleeding the caliper with the bleeder and the banjo and than below the master with the banjo. Link to comment Share on other sites More sharing options...
mossrider Posted October 30, 2020 Share Posted October 30, 2020 The air (bubble) will try to get to the highest point in the system it can get to since it's lighter than the fluid. Only it can't go down or around on its own and thus will be trapped at the top of the caliper or the top of the master cylinder or the highest point of the brake line itself. It must then be forced out; either by repeated brake pressure from the lever or a vacuum created by a bleeder. Moving the related parts to a relative position highest in the system makes it easier to bleed since the bubble will be presumably closer to a point of exit, the bleeder or the banjo bolt. Believe me, trying to force a small bubble along a line 8 or more inches using only the soft pedal pressure of a half bled system is an exercise in frustration. You'll move the bubble 2 inches per try and it can go right back where it started between attempts. Do you have to do this technique every time you bleed? Of course not but when you run into a stubborn bubble it can be the only way. For instance with my front brakes, I always finish with a last crack of the upper banjos at the master cylinder on the handle bars as they are the highest point of the system. I can get very good brakes without doing so but I can get great brakes by adding the upper bleed. Same goes out back. A soft pedal or lever means only one thing. There's air in there somewhere. This hydraulic system should be rock hard, especially with your SS lines. And to be clear, I'm talking about a spongy feel, not long travel caused by worn, dirty or junk parts. 1 Link to comment Share on other sites More sharing options...
Lone Wolf Posted October 31, 2020 Share Posted October 31, 2020 (edited) On 10/29/2020 at 4:57 PM, mossrider said: With all due respect, you still have air in there someplace. Correct. Otherwise the fluid would = pure hydraulic joy and feel hard as a rock. From the beginning it sounded like the rear master cylinder lost it's prime. I understand that you subsequently changed brake lines again and it is somewhat better, but still not good. When you had the banjo bolt holding the line removed, did you do the step where you put your finger over the hole, the steps noted on Sunday? That should have fully primed the master cylinder with no questions. 4. put your finger over the hole where the banjo was attached, effectively covering the opening. 5. pump the lever slowly. you will feel pressure on your finger every time you pump. 6. allow the fluid escape past your finger, but keep enough pressure on the opening as to not let any air back in. 7. when you feel that no more air is coming from the cylinder and only brake fluid, grab the brake line by the head of the banjo bolt and quickly release your finger and thread in the bolt all the way in. 8. tighten the banjo bolt to the specified torque. Mossrider is on the money when he says "The air (bubble) will try to get to the highest point in the system it can get to since it's lighter than the fluid." The bubbles SHOULD get shoved out during proper bleeding, no problems. I don't think you need the following part - this stuff really isn't that hard. However, if you truly primed the master cylinder, and tried everything you can - this will let you bleed that highest point by adding a bleeder nipple at the banjo bolt that sits on top of the master cylinder, at the highest point. You can buy it from Spiegler, or Revzilla "Within some braking systems, the banjo bolt may represent the highest point of the system. Add another trapped air purge point with a Spiegler Banjo Bolt Bleeder Kit." Edited October 31, 2020 by Lone Wolf Link to comment Share on other sites More sharing options...
ElGonzales Posted October 31, 2020 Share Posted October 31, 2020 Sometimes it is helpful to let the brake lever be pressed over night while the lid of the surge tank is loose . The pressure let the air bubbles shrink in the brake lines. Smaller air bubbles have a better chance to wander through the lines to the highest point of the system, especially if you move the lines from time to time manually or knock at them. My neighbour participated in BMW sidecar race series in the 80's-90's. He told me, sometimes they took the whole braking system off the racebike and hung it to the ceiling for hours. Link to comment Share on other sites More sharing options...
scat2me Posted October 31, 2020 Author Share Posted October 31, 2020 I started from scratch, replaced the rear line and bled the system again and its working now. Thanks for all the help. 3 1 Link to comment Share on other sites More sharing options...
shinyribs Posted November 3, 2020 Share Posted November 3, 2020 Glad to hear you got it sorted out. Sometimes they seen to fight you for no reason. Link to comment Share on other sites More sharing options...
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