AustinBike Posted January 22, 2019 Share Posted January 22, 2019 ...my brakes. I have XTR brakes on my singlespeed and I decided that now is the time to learn to bleed them myself. The good news is that the process is relatively simple for Shimano (SLX, XT and XTR) branches, but there are still a couple lingering questions that I need help on. First, after I did it the first time, everything felt great when I finished the job, but 20 minutes later it felt squishy again. I believe that this was because I did not pump them enough before closing them up. When I opened them and put the cup back on (with a little fluid) I pumped about 100 times and I saw a few small bubbles come out. After that they were more consistent but still a little soft. Totally rideable now, but not as tight as the front (which did not need bleeding.) I was wondering, because of the bend in the hydraulic cable, do I need to take the brake off of the handlebar and straighten out the cable? Do I have some air trapped somewhere down the tube? Second, the Shimano fluid seems pretty expensive. I'm willing to pay more for a better solution, but come on, it's oil. Is there a cost-effective alternative? If I do go with an alternative, should I flush all of the Shimano fluid out first? I'll post up a pictorial of how to flush the brakes on my site later this week. Quote Link to comment Share on other sites More sharing options...
AntonioGG Posted January 22, 2019 Share Posted January 22, 2019 I do all the work on all my bikes, and bleeding XTR brakes may be one thing that causes me to take it into the shop. There's something about the master cylinder and caliper design that makes it hard for bubbles to come out. I've looked into a syringe adapter to screw onto the master cylinder to draw a vacuum. If you read up on this, you'll find people put their bike vertically (or bleed them off the bike), tap on the lines for a while, leave the cylinder open overnight, etc. I've done all these and I still get not solid feeling brakes. One thing I recommend is to check your disc thickness. I discovered mine were thinner than spec and that was not helping on the brake feel. Quote Link to comment Share on other sites More sharing options...
Chief Posted January 22, 2019 Share Posted January 22, 2019 What model version XTR brakes are they? I have XT on both my bikes one set of 785 and the other 8000 series. The 785's are easier to bleed and give a much firmer lever feel than the 8000's. The 8000's can be a PIA to bleed due to the small reservoir and never feel as firm as the 8000's. For some reason the design of the 8000's make them prone to having trapped air somewhere in the system. I use a two syringe method for bleeding, forcing fluid up to the lever from the caliper. Tapping on the caliper and lever helps also getting the caliper in the lowest point helps too. Sometimes leaving the reservoir open and clamping the lever with a zip tie or rubber band around the lever for a few hours helps too. I also noticed with the 8000's that when the pads get worn the lever can have a some what spongy feel. 1 Quote Link to comment Share on other sites More sharing options...
AustinBike Posted January 22, 2019 Author Share Posted January 22, 2019 Good suggestions on the XTR, since I hang my bikes vertically anyway, maybe I will try that this afternoon. The good news is that it was totally rideable vs. last week when I had to pump it 9-10 times before it would hold. Quote Link to comment Share on other sites More sharing options...
Teamsloan Posted January 22, 2019 Share Posted January 22, 2019 Step 1: remove the brakes from the bike, set aside. Step 2: install Hopes. 😄 Shimano uses mineral oil, I would be shocked it the Shimano brand fluid had any characteristics that would be advantageous over any other mineral oil designed for brakes. Heck, Seth's Bike Hacks just released a video last week of him bleeding his Shimano brakes with baby oil (it worked but smelled like diapers or something). 3 Quote Link to comment Share on other sites More sharing options...
AntonioGG Posted January 22, 2019 Share Posted January 22, 2019 1 hour ago, Chief said: What model version XTR brakes are they? My calipers say BL-M987 on them. Quote Sometimes leaving the reservoir open and clamping the lever with a zip tie or rubber band around the lever for a few hours helps too. I forgot, I tried this too. I got them to a point they were decent, but.... Quote I also noticed with the 8000's that when the pads get worn the lever can have a some what spongy feel. ...yeah, it only took a couple of months of riding and some pad wear and I'm back to having to pre-pump the brakes before I really want to brake. I did some calculations and I think I posted them on the other thread. It doesn't take much wear on the pads and disc for the small volume in the tiny cylinder to become a limiting factor. Quote Link to comment Share on other sites More sharing options...
AntonioGG Posted January 22, 2019 Share Posted January 22, 2019 Sorry for piggy-backing onto your post AB, hopefully we both get sorted out here. Quote Link to comment Share on other sites More sharing options...
AntonioGG Posted January 22, 2019 Share Posted January 22, 2019 4 minutes ago, Teamsloan said: Step 1: remove the brakes from the bike, set aside. Step 2: install Hopes. 😄 Shimano uses mineral oil, I would be shocked it the Shimano brand fluid had any characteristics that would be advantageous over any other mineral oil designed for brakes. Heck, Seth's Bike Hacks just released a video last week of him bleeding his Shimano brakes with baby oil (it worked but smelled like diapers or something). I'm looking forward to Seth's follow-up of the internals. Though, I bought the 1 liter container. It's way more economical than buying the small bottles, and since it's mineral oil, you don't have the issue with the opened brake fluids. I do love my Hope brakes (have them on 2 other bikes, rode 10k miles in one of them, only had to bleed them when I damaged a hose). The negative against the Hopes is the DOT 5.1 fluid. It's pricey, and it absorbs moisture. Quote Link to comment Share on other sites More sharing options...
AustinBike Posted January 22, 2019 Author Share Posted January 22, 2019 35 minutes ago, AntonioGG said: Sorry for piggy-backing onto your post AB, hopefully we both get sorted out here. This is why I posted it - looking for people's input Quote Link to comment Share on other sites More sharing options...
Anita Handle Posted January 22, 2019 Share Posted January 22, 2019 y'all with y'alls bougie XTR breaks... 2 Quote Link to comment Share on other sites More sharing options...
Anita Handle Posted January 22, 2019 Share Posted January 22, 2019 My old XTs from... 7 or 8 years ago are still kicking. Hard to beat those XTs for reliability. I do get a weird lever feel fairly often during rides, like one moment it goes a certain distance to engage then suddenly it requires a lot more lever pull to engage. I assume it needs a good bleed. With my Devinci, I installed SRAM. I loved the feel of my SRAM Guide R brakes. Strong, good enough modulation, easy to bleed (with the kit at least). But I ended up with the issue where the lever mechanism starts catching. They've supposedly fixed it but I felt a bit burned by Avid. Now I'm running Magura MT-5 and they are great. The best modulation so far and very strong with the quad pistons. I did run into an issue where a shop in Bentonville stripped the bleed port on the lever and claimed that the brakes were simply not taking a bleed because..., you know, they're Magura. I was going to replace the whole lever but, because the Maguras are flip-floppable and have bleed ports mirrored on both sides, I ended up just supergluing the bleed port screw on one side and bleeding it through the other side. I had completely removed and emptied the lever so I ended up needing a second bleed to get it nice and firm and consistent but they are working nicely again. Pretty easy to bleed, imo. Downside of Magura is that plastic lever body and the lack of local availability of little maintenance bits and pieces like olives and hose barbs and such. NOT THAT ANYONE ASKED... ha Quote Link to comment Share on other sites More sharing options...
Teamsloan Posted January 22, 2019 Share Posted January 22, 2019 1 hour ago, AntonioGG said: I do love my Hope brakes (have them on 2 other bikes, rode 10k miles in one of them, only had to bleed them when I damaged a hose). The negative against the Hopes is the DOT 5.1 fluid. It's pricey, and it absorbs moisture. DOT 5.1 pricey? $10 gets me plenty, then I just screw the cap on really tight. "y'all with y'alls bougie XTR breaks... " Nothin' more bougie than my gold hope X2s on a handed down Blur LT. 2 Quote Link to comment Share on other sites More sharing options...
Ericbike6 Posted January 22, 2019 Share Posted January 22, 2019 I was having the same problem with my front brakes one weekend. When bleeding they would come up and be great, 20-30 minutes later needed pumping and felt mushy. Bled them again, zip tied the lever to bar, very quickly found the weak spot in the hose. Right at the banjo fitting to the caliper. Might be something to look into also. 1 Quote Link to comment Share on other sites More sharing options...
AustinBike Posted January 22, 2019 Author Share Posted January 22, 2019 24 minutes ago, Ericbike6 said: I was having the same problem with my front brakes one weekend. When bleeding they would come up and be great, 20-30 minutes later needed pumping and felt mushy. Bled them again, zip tied the lever to bar, very quickly found the weak spot in the hose. Right at the banjo fitting to the caliper. Might be something to look into also. Do you seal it back up when you zip tie the lever? Assuming so.... Quote Link to comment Share on other sites More sharing options...
Ericbike6 Posted January 22, 2019 Share Posted January 22, 2019 1 hour ago, AustinBike said: Do you seal it back up when you zip tie the lever? Assuming so.... actually had to replace the line. It just had a soft spot in it, it was soft enough that air was getting in, giving us a good feel, then going soft after some time. Quote Link to comment Share on other sites More sharing options...
Ridenfool Posted January 22, 2019 Share Posted January 22, 2019 29 minutes ago, Ericbike6 said: actually had to replace the line. It just had a soft spot in it, it was soft enough that air was getting in, giving us a good feel, then going soft after some time. Don't they have a pill for that now? Quote Link to comment Share on other sites More sharing options...
Teamsloan Posted January 22, 2019 Share Posted January 22, 2019 16 minutes ago, Ridenfool said: Don't they have a pill for that now? Sure do... Quote Link to comment Share on other sites More sharing options...
rockshins Posted January 22, 2019 Share Posted January 22, 2019 Extra step if you haven't tried is to adjust the lever reach and free stroke before you start. Have heard every which way, to have the lever reach and free stroke fully open, or to have the lever reach fully open and the free stroke closed and the opposite of that. The best bleed I have gotten is to have the lever reach all the way to the bars (closed) and free stroke all the way open, but who knows. Seems like you can have extra air in those spots. 1 Quote Link to comment Share on other sites More sharing options...
Ericbike6 Posted January 22, 2019 Share Posted January 22, 2019 2 hours ago, Ridenfool said: Don't they have a pill for that now? Yes they do, and you can get monthly supplies shipped right to your house now!! 1 Quote Link to comment Share on other sites More sharing options...
gotdurt Posted January 22, 2019 Share Posted January 22, 2019 (edited) Additives are really the only difference, from what I gather. This is what I'm using (Febi/Bilstein Nr 06161, aka M6162), based on a thread or 3 that I found elsewhere (mtbr? Pinkbike?); it's supposed to be about the closest you can get to the Shimano oil. You can get it at NAPA, I think I paid about $10 at the one in Round Rock. There's also a synthetic version, and they say to avoid that... One thing I do not like about Shimano brakes is the on/off switch feel (lack of modulation), and this seems to help with that... I first bled just the rear so I could compare with the front and see if I could tell a difference... and IMO there seems to be slightly more feel/modulation, with the same full bite power. Maybe a slightly higher viscosity? I don't know, but I dig it. Edited January 22, 2019 by gotdurt Quote Link to comment Share on other sites More sharing options...
larlev Posted January 22, 2019 Share Posted January 22, 2019 I have gallons of Mineral 150 that we use in refrigeration compressors if any of you want to try it. 😁😁 Quote Link to comment Share on other sites More sharing options...
Bamwa Posted January 23, 2019 Share Posted January 23, 2019 My BB7's need a good bleed yo. 1 1 Quote Link to comment Share on other sites More sharing options...
AustinBike Posted January 23, 2019 Author Share Posted January 23, 2019 11 hours ago, gotdurt said: Additives are really the only difference, from what I gather. This is what I'm using (Febi/Bilstein Nr 06161, aka M6162), based on a thread or 3 that I found elsewhere (mtbr? Pinkbike?); it's supposed to be about the closest you can get to the Shimano oil. You can get it at NAPA, I think I paid about $10 at the one in Round Rock. There's also a synthetic version, and they say to avoid that... One thing I do not like about Shimano brakes is the on/off switch feel (lack of modulation), and this seems to help with that... I first bled just the rear so I could compare with the front and see if I could tell a difference... and IMO there seems to be slightly more feel/modulation, with the same full bite power. Maybe a slightly higher viscosity? I don't know, but I dig it. After last night's R&I my brakes were squishy again. Part of the problem (I am guessing) is that when I got the bleed kit it had a small bottle of oil so I have been very careful in how much I pump in. Went on Amazon last night after the ride and bought a liter of the stuff. Will be here this weekend. Gonna totally over pump the fluid through and see if there is something in my process or in my tubes that was creating the problem. If that does not work it may be time to take it to a professional. But I am so far down the rabbit hole on this that I want to leave that for the last resort. 1 Quote Link to comment Share on other sites More sharing options...
notyal Posted January 23, 2019 Share Posted January 23, 2019 3 hours ago, AustinBike said: After last night's R&I my brakes were squishy again. Part of the problem (I am guessing) is that when I got the bleed kit it had a small bottle of oil so I have been very careful in how much I pump in. Went on Amazon last night after the ride and bought a liter of the stuff. Will be here this weekend. Gonna totally over pump the fluid through and see if there is something in my process or in my tubes that was creating the problem. If that does not work it may be time to take it to a professional. But I am so far down the rabbit hole on this that I want to leave that for the last resort. The good thing about a failed brake bleed is that when you take it to the shop, you can just say "yeah, I don't know, they are just kinda mushy". This is far less embarrassing than showing up with all the pieces of your fork in a grocery sack. 1 Quote Link to comment Share on other sites More sharing options...
Ridenfool Posted January 23, 2019 Share Posted January 23, 2019 Removing the brakes from the bike and hanging them with the caliper down makes it easier to get the air out, as someone suggested above. Another thing to do is rotate the caliper around with the line end up to allow any air that may be trapped in an internal void find its way up to the line so it can be flushed out. Pump the fluid in from the low point, retrieving it at the high point to help the bubble along in the direction it wants to go anyway. Paraphrasing Ty Webb (ancient pop culture reference) "Be the bubble." Na na na na na na Quote Link to comment Share on other sites More sharing options...
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