front brake problems

[warfman41]

Hey guy's, still tinkering around with the old 79 xs 1100F i got while back. Have got it running great, Probably wouldn't hurt if i went ahead and re-built the carb's, just haven't got to that yet. Got my new Dunlop D 404 tire on the back the other day, and got my hard bag's mounted on for the first time since i got it. Really like the look. With the Vetter fairing and the bag's, got a nice "big bike" look. Really like the old bike...but... having some serious problems with my front brakes. It had a caliper pouring fluid when i got it, so i ordered a whole front brake system off another 79 xs11 off ebay. Started to put it on, and to my dismay, the calipers were different. So...i went the re-build route. Started on that yesterday when i got home from work, and all went well up to a point. Gave the caliper's a good cleaning, piston's were in good shape,put in the kit's and put it back together with a new set of pad's in both sides. After three hour's of pumping and bleeding and still having nothing, I was starting to wonder. The master cylinder was seeping a little fluid, so i figured it must be by-passing and be no good. Luckily, i had the mc off the other brake system. I put it on when i got home today, filled it up with dot 3, and started bleeding. Master cylinder felt better than the old one, and i thought i was going to get somewhere, but i still can't get any brakes. seems like there's good pressure when you loosen the bleeders, but it just won't pump up. If anyone has any idea's as what could be the problem, i would sure appreciate it. Thank's guy's, warfman41

[TopCatGr58]

Hey Warfman,

First, do you have a clear tube stuck on the end of the bleeder screw so you can see fluid and bubbles coming out?

Secondly, folks recommend that before you put the brake line on the MC, use your finger over the end of the MC, and bleed it to make sure you're getting pressure, then attach the brake lines. Also, check the spooge hole in the new MC to make sure it's open and clear, not clogged! See tech tips for info and photos!

Another trick, but a litttle bit of a PITA is to take the calipers OFF the bike, put a piece of wood as thick or thicker than the brake rotor inbetween the pads, and raise the calipers up close to the same height as the MC, and then perform the bleeding, this way the bubbles won't keep trying to rise back up thru the brake line when they are way lower than the mc.

Others have suggested devices like a mighty vac, but that involves extra $$ for more tools and such...your choice!

ALSO, did you scrape out the corrosion that builds up inside the caliper O-ring groove before putting the new ring in? Otherwise it can make the O-ring too tight and the calipers won't release!

T.C.

[CaptonZap]

One other thing you might try is to position the front fork so that there are no portions of the brake line that have a hump in them. Usually side stand and left steering lock should do it. Look at the lines. Is there any place a bubble could hang up, if it were trying to go up to the MC?
If not, let it set overnight, take an asprin, and try the brakes in the morning.
This only works if the spooge hole is open, so check that. CZ

[jjz28]

I used a big syringe on my 750 and 1100 and it works awesome. Just get a big syringe like for mixing gas and I used clear tubing on the end the hook it to the bleeder and it will fill the master cylinder backwards. That is the easiest way i have found. 10 minutes and you have good brakes and dont have to pump it a billion times.

[GLoweVA]

Jeff, are you saying you fill thru the bleeder?

Wow, I would have never thought of that! That way it pushes all the bubbles up and out the MC. Naturally the bubbles want to flow up anyway, so why fight it.
Ingenious!

[warfman41]

Thank's guy's

Thank's a million guy's. Everyone's input is invaluble. But, i suppose the take an aspirin and try them in the morning is the winner!! Got home today, and took it down the road, tried using the front brake's, and noticed i had a little something. Rode around awhile, playing with them, then came home and started bleeding again, and wallah, got brake's now that would stop a Mack truck. A fellow at work told me today that i should have let it sit with the bleeder's opened up and the mc top off and let it gravity fed for a while. I suppose sitting overnight and today, the old girl kinda took care of it for me. Anyway, i've got some really good stopping power now, and thank's again to everyone for the input. warfman41