| Author | Message | ||
     Jackbequick |
I want to replace the brake fluid on my M2. I've read Henrik's excellent article and am familiar with the concepts involved. I have a suction type bleeder system that I think will suck the old fluid out the bottom, replacing it all with new if I keep the reservoir topped up at the lever. Has anyone tried this? I'm not sure the brake systems will let me pull fluid through the system from the filler. I expect I might have to seal the bleeder against air leaks with Teflon (thanks again for the details on that Henrik). In principle, I am using the suction from the bleeder to pull the fluid down from the reservoir instead of pushing it up from the syringe. Henrik - One question. When you drain the system, do you let time and gravity do it and drain it through the bleeder? I don't intend to drain mine if the suction will work but I will if I have to and I would prefer not to break the seal on the banjo. Thanks to all for any help. Jack | ||
| Bluelightning |
Jack, I drain mine through my suction bleeder at the bleeder valve. When I re-fill fill it from the reservoir and bleed it down to the valve again using my suction bleeder. Takes about 15 minutes for each end, and that's giving me time to screw around. Leave your banjo fitting locked down and you'll be good to go. | ||
| Bomber |
Jack -- many folks use that method (including Bluelightening) with great success. for who knows what reason, I've had much better luck with Henrik's method -- porhaps it is becoase the fluid is being moved in two directions, rather than one, the bubbles are more easily cleared from the system -- Henrik's method has gotten my M2 brakes much firmer than they were new, and does an aces job on my own personal benchmark, the much loved but cantankerous 31 ford -- | ||
| Jackbequick |
Thanks to all, I'm going to give it a try with the suction kit then. I just wasn't sure that the check valves and piston would allow a continuous flow out the bleeder. Jack | ||
| Ragnagwar |
I used the Mityvac last fall to do my brakes and had no problems at all. Filling from the bottom seems to be a better way of doing it if the system has been completely drained. Easier to push all the pockets of air out that way. | ||
| Bigdaddy |
Hey JBQ, You won't have any problems with or without the suction. I've always been a big advocate of gravity in these matters. Henrik's method is to my knowledge the quickest way to accomplish it. G2 | ||
| Henrik |
Jack; I have a MityVac that I use to empty the system. Then I use the syringe method to fill it back up. Henrik | ||
| Blake |
Henrik, I'll not spare my opinion; your method sucks.  It sure does transform the braking action though on my Buell. I was astounded at how much better my front brake performed and felt after using your recommended brake bleeding/transfusion method. Actually I've been too cheap to purchase a vacuum device and just use the brake lever and some patience to push all the old fluid out before injecting via syringe. It is amazing how a simple device like the brake bleeder syringe can improve the motorcycling experience. The syringe brake bleeder/refiller kit that I was able to find is from K&L Supply. They call it the EZE Bleeder. It consists of a large (~ 1" diameter) syringe, various heavy duty clear adapters for mating to brake bleeder nipple(s) and a nice container to keep it and your tool box nice and clean. K&L Supply Part # is 356515. Cannot find it anywhere, but my local independent moto-shop can order them. Maybe one of our sponsors can hook us up? Retail is somewhere around $29 I think, not sure though. | ||
| Bomber |
you can, for approximately the same amount of dough, find a verteranarian's supply house, order up the syringes ya need, cop some hoiuse from the nearby NAPA store, and make 6 setups just another data point for those thrifty folks ;-} | ||
| Road_thing |
What Bomber failed to mention is that you can then share the extra 4 or 5 syringes with your buds. Thanks again, man... rt you still coming down this way next month? | ||
| Bomber |
YOu are very welcome, Thang -- Hey Blake -- I still got an extry syrine thingie -- ya need one? very likely, if the authorities don't catch on ;- } | ||
| Buellistic |
What are you BUELLers out in BUELLdom doing ??? Pushing 88K and have never had to BLEED my Calipers(front or rear) !!! "PREVENTIVE MAINTANCE" works for me !!! | ||
| Road_thing |
But Lafayette, wouldn't the renewing of fluids come under the heading of PM? I mean, you do change your oil and stuff once in a while, right?  rt Bomber: excellent! there's a jug of old scotch with yer name on it at the ranchito... | ||
| Bomber |
Buellistic -- never? wow! the first brake system that is entirely air/water tight in the history of upright human kind! Thang -- ;-} | ||
| Jackbequick |
The brakes might get better if you drained and refilled them. I think the SM calls for changing the brake fluid every year or two years. The stuff at the caliper will usually be darker and grungier looking than the stuff in the reservoir and you may find some water from condensation in it because the water goes to the low point. Water in a brake system is real bad news if rust develops and a cylinder get pitted. It costs less than $3 for a pint of fluid and that is more than enough. If you have to buy a Mity-Vac it adds about $30 to the first use but you've got a great tool that you can use for a lot of other things. I used a Mity-Vac and Henrik's tips for sealing the bleeders and it went fine. The brakes felt good before I did it but felt great afterward. Some of the things I learned: 1 - When you pull the bleeders to put the Teflon tape on, the fluid will drain. A layer of clean tee shirt material around a 1/4" wood dowel works fine as a temporary plug for the leak (DOT 4 can be hard on paint!) while you put the Teflon on the bleeder screws. 2- The yellow gas service Teflon tape is thicker than the white stuff and much easier to handle and work with. After wrapping, "chase" the thread with a fingernail to get the Teflon down in the threads well, wrap it snug and trim it above the hole as Henrik's photos show. 3 - I used a piece of 1/4" silicone (bright yellow) fuel line for the suction line to the Mity-Vac, it is "stretchier" than the vinyl stuff. 4 - Drop a 8mm box end over the bleeder, push the suction line on down against the wrench, and use a real small cable tie applied with a riding turn (go around 2 times so it crosses itself) to seal against air leaks. 5 - You only need to open the bleeder 1/4 to 1/2 turn when you start pulling the new/clean fluid down. If you open it quickly, it seems to pull the bubbles through better. Only open it for about 2 seconds, then shut it. 6 - Check the reservoir each time you shut the bleeder to make sure you don't pull any new air into the system. 7 - After I was seeing no more bubbles, I pulled another 2 or 3 more shots just to make sure I had all the bubbles and old stuff out. 8 - You can work the cable tie up and off the bleeder screw when you pull the suction line, then force it back down to seal on the next bleeder. I've only got about 35 miles on my M2 since I did the brakes and that was in 30F weather with heavy gloves. But the brakes, particularly the rear, felt much better. I think I sensed the front brake was actually happier. :>  Jack (Message edited by jackbequick on March 20, 2006) (Message edited by jackbequick on March 20, 2006) | ||
| Henrik |
Thanks Blake. I appreciate that. Glad you notice a difference in braking. I know I did, but it's kinda difficult to explain how much of a difference it makes in brake feel. It's a bit like something I was trying on the SV to decrease the brake force of the rear caliper. It's currently much too strong, so someone suggested "bleeding" an air bubble into the system. And while it kinda worked, it also completely eliminated all feel of the rear brake (not that it had much to begin with), but would also be difficult to replicate for consistency next time I bled the rear brake. My guess is, that a less well bled front brake suffers from the same issues. Anyway ... glad you like it  Henrik | ||
| Jackbequick |
Henrik, You might try reducing the braking surface on the pads by filing or cutting a series of grooves across the braking material. You want to cut the grooves all the way across at a right angle to the rotation to keep the wear full width. Jack | ||
| Henrik |
Thanks for the advice Jack; what I've done so far is to cut back the outer edge of the pads by 10 mm, which was not enough. Next step is GSXR rotor (which is 10 mm smaller in radius than the stock SV) that I'm having drilled/slotted to further cut down on the swept area. It'll lighten up the unsprung weight as well, so that's an added bonus. If that's still not enough I'll try slotting the brake pads as you mention and last step is finding a bigger bore master cylinder. Btw. cutting brake pad material is a bear. Wore down 2 hack saw blades just cutting those 10 mm off the pads. Henrik | ||
| Buellistic |
"PREVENTIVE MAINTANCE": Change the fluid in both master cylinders once a year and you do not have to bleed/refill system which has worked for me for 87K PLUS !!! Wipe out(clean) master cylinders with a clean old t-shirt ... Oil change with FILTERS every 3K !!! | ||
| Jackbequick |
I didn't realize those were that hard. I used to use a coarse triangular file on the shoes on my dirt bikes and it did not take too long to file several grooves 1/4" wide and 1/8" or so deep. I did those diagonally across the shoes to lead any dirt and residue to the open side of the hub, any reduction in braking forces was incidental and acceptable. I had a Montesa King Scorpion enduro bike in the early 70's that came with the same twin leading shoe drum brake that was used on the Montesa and Bultaco road racers of the time. Magnificent braking for the day, complete with a big air scoop for cooling. I wound up blocking off the dirt and water scoop with an aluminum plate filing deep grooves across both shoes, and finally adjusting it into a single leading shoe brake to get it where I could use the front brake in the dirt much. I loved that bike but it went away for a Bultaco Alpina eventually. I was stationed in Spain in the Navy at the time and rode one of those to work nearly every day. Had to have a bike so the wife could have the car. Also had to teach the wife to drive so that she would need the car... Jack | ||
| Henrik |
Cool story Jack. Thanks for sharing. Neat trick with the wife too Henrik | ||
| Blake |
Lafayette, I used to do exactly like you recommend and my front brake was perfectly fine. It's just that it got even better when I reverse filled the system. It really was astounding how much firmer the brake felt. I also did the tapping on the caliper with a wrench as I refilled the system. That apparently dislodged some very small air bubbles in the system. I had been racing prior to this and the newfound improvement did make a difference on the track in that it provided better feel and precision. Give it a go and see if you don't find the same result. I'd be surprised if you don't. | ||
| Jackbequick |
I did not have a syringe or I probably would have tried Henrik's procedure. I did have a Mity-Vac so I used that. When I thought about it, I could see where his way might work better because air bubbles might go up faster and farther than when they are being pulled down. Any bubbles would probably move closer to the top with each in and out cycle. And it may be that the bubbles have a better path out upwards than they do downwards. There are some professional brake bleeding systems that put a special sealed cover with a suction fitting on the reservoir and pull the fluid up from a supply of fluid attached to the bleeder. One problem with those is that suction air leaks at the bleeder screw will bring tiny bubbles into the new fluid. Jack | ||
| Tgontz |
On a system that has two bleeder valves for each caliper would I have to do this at each valve? |
