Hi
[b]Short version[/b] - Basically I keep leaving air in system. What the best way to bleed them?
[b]Long version[/b] -I seem to keep getting the lever going to the bar recently when I've tried bleeding these. I've bled another pair the same way and they've been fine. Basically lever's for both front and rear have decided to be to pull right to the bar sometimes. Re-bled the rear as per instructions and it decided to do it again, only once though. When these were originally bled all seemed fine for a good few months. This time however I left the lever closed (brake on) for a while and some small bubbles appeared. Also tapped the brake lines and caliper etc..
I basically bled them the the top down, but then pushed some fluid back through the system with the brake off and then top to bottom again..Pushed about one syringe worth's excess fluid through
Only thing that I don't like with the instructions is the way the caliper grub screw should be tightened after the oil cap at the lever has been tightened, as a small amount of oil always seems to come out as the grub screw needs to be inserted. So I insert the grub screw and then topped up the oil at the brake lever again. Also I wound out the reach adjustment before the bleed and then readjusted after. Found this works before. Thing is I am pretty certain it's an air problem as when I re-bled the rear I found a couple of small air locks came through the system, although everything seemed fine...for the majority of the bleed, and these additional air locks only appeared at the end the excess syringe content.
So in short, how do I ensure all air locks are removed?
Any advice greatly appreciated.
Thanks
You should be bleeding them bottom to top. Squirt the fluid into the caliper, suck it back a bit, squirt it back in, repeat until bored.
ok thanks 😀
Bloke in lbs said to me his opinion that Mag Louises take two or (mostly) three bleeds before they are spot on.
Yep, I have bled them from bottom to top. Also, when the reservoir is full, gently, and I mean gently, pull the brake lever back and release it gently too. There will be some air trapped there IME.
I find the rear one hardest, it may be worth trying to get the bike. (or hose ) more vertical as the front usually is.
EDIT, if you bleed them to satisfaction, then put the top cap and rubber thingy back onto the reservoir. Removing the syringe and putting the grub screw back in, can be a bit of an affair as you need to be dead quick I think or start again.
slowoldgit - do you mean 2 or 3 complete cycles of the fluid? or 2 or 3 complete bleeds - ie ride then - redo etc
cool thanks everyone. I'll give them another go. Thanks.
Boss brakes BTW. Mine go to the Alps every year and every year my brakes are the only ones that seem to perform flawlessly compared to those of all my mates.
Don't loose hope, they are worth the effort and if you do it properly you'll probably not need to do it for years or until you need to change your hoses.
It was a while ago, and I think he meant complete bleeds.
yeah cool. I rode some in the alps too on a ht and dragged them loads ( i know), but had to really in sections and they were faultless even with 180 front 160 rear rotors and the original hoses:-)
Recently put some braided hoses on..
ok thanks s/o/g.
thanks everyone.
I did my Louises (2008 variety) last weekend for the first time and it took a couple of goes to get the back one done properly. I found cycling the fluid as slowly as possible helped, as did cycling the lever gently a couple of times and waiting a few minutes between each pull and push of the fluid. I must have cycled the fluid 10-12 times on the back brake and maybe half that for the front. Like Luke said, I tried to get the rear hose as vertical as possible by rotating the bike in my workstand.
Good luck!
ok.