Originally Posted by Jack of Heats JoH
The Kawi manual indicates brake lines should be replaced every 4 years along with rebuilding the calipers etc.. I have a 2011 versys with original brake lines 9K miles on the bike. I replaced the fluid when I purchased the bike last spring at 3K miles. The brakes are functioning properly and I have no issues with them.
My current plan is to replace them at the end of 2018. I do about 6K miles a year so that will put me at 15K miles time for valve check, new tires, chain sprocket, brakes etc..
Not a big job to replace brake lines so I could do it sooner if need be.
My guess is the 4 year replacement is just a conservative recommendation by kawi. However if brake line replacement is a critical safety issue with potential of sudden brake failure I would like to know.
Also I am going to replace with made in USA stainless steel brake lines. Will these also need to be replaced in 4 years or are SS lines good for the life of the bike?
The only thing that really causes rubber hoses to deteriorate is UV light and perhaps time. If you don't park your bike outdoors without a cover for long periods of time the lines should last at least 10 years and probably much longer. That said if you do replace use braided SS lines, they greatly improve brake feel because they don't expand with pressure, just make sure you do a really good bleed job as even microscopic amounts of air left in the system will negate any benefit from them.
I had to top up the front brake reservoir 6 or 7 times to get all the air out. Watch for tiny bubbles coming out of clear plastic hose connected to collector bottle. They continue to come out for a while after the bulk of the air is expelled from the system. You can pour what you collect back in the reservoir. Given my experience I would expect most vacuum pumps used for this remove most but not all of the air. A collector bottle is really the only way to be 100% sure all the air is out of the system.
1) start with caliper furthest from brake handle and switch back and forth between calipers every so often. It takes a while to get all the air out.
2) to start fluid flowing out of the bleeder valve you will first need to expel the bulk of the air from the system. Fill the reservoir with fresh fluid. Opening the bleeder valve 1/2 turn and using your thumb as a valve on the bleeder valve hole, block the hole before releasing the brake lever so as not to suck air back into the system. Unblock the hole when squeezing the lever to let air out. Once a steady stream of fluid is coming out of the bleeder valve close it and connect the collection bottle and go to step 2.
3) connect collection bottle to bleeder valve with clear plastic hose it comes with, a brake bleed collector bottle with hose will only cost ~$5
4) open bleeder valve ~1/2 turn and squeeze lever but do not release until bleeder valve is closed
5) repeat ~50 times or until no tiny bubbles in collector hose. Do not let reservoir run dry or you will need to start again. Keep reservoir topped up as fluid is exiting from bleeder valve.
The result of doing this however is a rock hard brake lever where you can feel pads suddenly contact the rotor with your right hand and there is no softness or vagueness in the system. You'll be able to brake a lot harder, with practice, because you will be better able to better sense imminent front wheel lock up with your right hand. If you can move or squeeze the brake lever once you feel the the initial resistance of the pads contacting the brake disks it is a sign that something is giving, either air in the system is compressing or the brake lines are expanding. The benefit of SS brake lines vs rubber lines is they do not expand with brake pressure.