tubing size for brake bleeding and what's the chance I introduced air into my lines?
After watching a few videos decided to give changing out my brake fluid a go on my older 05 R1 since it seemed easy enough .. picked up a mityvac 8000 since it seemed like it would be easier then doing the whole pump the lever, open the bleed valve, rinse and repeat..
Some had suggest to make it even easier pop the reservoir and removed all the old brake fluid first, fill with fresh and then move on down to the bleed screws so and not have to waste time flushing all the old stuff in addition to what was in the lines and wouldn't you know.. like motherfucking Goldilocks the tubing supplied was too big or too small for the bleed screews. Same with the Bleed screw adapters.
The adapters were listed as 6mm and the tubing I believe was 6mm(amazon says 6.4mm) and the small was 4mm(4.4mm), .. so I'm guessing 5mm would do the trick but just want to get some actual confirmation.
so until I can get tubing that will create a tight seal and not let air slowly leak, I just made sure it was to the fill line and replaced the cap but is there a chance I introduce air into the lines by first emptying the reservoir, even if I didn't engage the break at all?
Posted Jun 26, 2018, 4:55 AM UTC
You’re not supposed to completely empty the reservoir, just enough to make sure no air gets in and then you add to that old fluid. Go to a hardware store and get tubing that’s very small in diameter so it fits snug against the bleeder valve, you can always stretch the tubing with a pair of needle nose pliers.
Yeah, that's what I thought but deferred to a video of someone emptying before starting, I knew once you started at the lower bleed screws you didn't want it to go too low to avoid air getting pulled into the lines but going forward will just empty enough but not pass the low line.
then it sounds like the 4mm tubing I already have will work, I was just trying to work it on but it was not wanting to budge after about half way on but sounds like if I stretch it a tad with a pair of needle nose pliers I'll be good.
Thanks, I'll try that in the morning and providing that works, that will also deal with any air that I may have introducing by trying to "save time".
Yea just stretch it. If you have a heat gun or blow dryer you can also warm it up so it will go on easier, or lube it with some brake fluid. You want that bad boy snug.