I've got an 86 VFR and the front brake lever has always been soft/loose (as in I can pull it almost to the bar before it tightens up the brakes. I've done the following in the last 2 weeks: Rebuilt the calipers with new seals from Honda Replaced the bleeder valves with speedbleeders (old valves were crushed) Replaced the front lines with a Galfer 2 line stainless setup Rebuilt the master cylinder with a K & L kit Replaced the pads with new EBC Sintered pads Bled and re-bled the brakes MANY times with Valvoline synthentic fluid If I adjust the lever so it is as far away from the grip as possible I can still pull it with two fingers until it hits my knuckles before it finally stops. The lever is very soft for the entire pull and even when it's tight it feels spongy like I am forcing the lines to buldge a little. This would seem to be a bleeding problem; especially at the master cylinder line bolt but I can't get any more air out of the system; including from that joint. I'm familiar with bleeding brakes and even bought a Mityvac today to try and pull any bubbles out but have had no luck. Just to make sure I wasn't bleeding things wrong I tore the clutch master down today to clean it and put it back together and I bled that in 5 minutes after I bolted it back up so I don't think I'm bleeding anything wrong. What am I missing?
Still sounds like air in system. if you have replaced all the seals correctly and it is still spongy then it can only be air. check for leaks and get the air out.
You sound like you know your stuff dude. I would just be restating the obvious of air in the system, however, maybe your brake fluid has been contaminated with moisture/water. Might want to drain it again and use a fresh bottle...ya know this point is probably moot since you have bled and drained the system many times. When you are drawing fluid thru the system with the mighty vac, do you still see bubbles visible as you finish up? Also, are you constantly watching the fluid level in the master cylinder to make sure that it doesn't run too low and starts pulling in air?
Danimal, could any of the seals be letting air in but not letting fluid out? I'm definitely not loosing any unless it's in such small amounts I never see it. I just went for a 40 mile ride and it's still at the same leve. So you guys both think it's just air? I hope so. I've been tapping the joints etc. too just to hopefully dislodge any thing that's trapping air. I did just buy some new fluid today so that's good and I'm keeping an eye on the master level. The vac didn't work as well as I hoped. Only one of the bleeder sealed good enough to not draw air back in around it so that one was easy to bleed. I bled the other onw with the lever and it cleaned up nicely as well. It seemed to get a little better when I went back and bled the banjo joints by the master so I'm thinking about picking one of those Galfer master cylinder bleeders. I've always wondered; could I swap a master from another bike?
If you do a reverse bleed you will be sure to get all the air out. I had some frustration doing my '95 until I made a set of reverse bleeders from two 60CC vetrinary syringes, tubing and zip-ties. You'll never want to do it another way once you see how well it works and the air you thought was gone. I could make you a set of bleeders, if you're interested. Douglasthecook got a kit from me and wrote up a review a few months back. I think he even had speed bleeders, but I think with this method you're better off without them. $12 plus actual shipping to your door via USPS. Shoot me a PM if you're interested.
Thanks for the offer Vlad, but I think I've got all the materials to do a reverse bleed except standard bleeders. That might be the best solution if everyone thinks it's an air problem; just break down and buy some regular valves. So no-one things any of my components could be faulty? I don't have a good reason for it but I just wonder if my master cylinder has something to do with it.
over night try: take the lever and squeeze it as tight as you can get it, then tie it like that so the lever always has pressure on it. leave it over night, and then do a quick bleed in the morning. I have heard countless people report that it works, but never been in a situation to need to try it.
Did you burp the MC banjo bolt. Can be done with 1 person, but easier with 2. While holding pressure on the brake handle, crack the banjo bolt until fluid starts coming out and then tighten again. Because the line is so big (compared to the bleeder valve) the release and tighten of the banjo bolt procedure has to be done quite quickly. Also noticed that you are using synthetic brake fluid. Is that DOT 5? If it is, google combining DOT 5 and DOT 3 or 4 fluid and components.
