Front brakes

[mack]

Terrible day today. Doing all the small things before the start up tommorrow. One thing outstanding was the front brakes. Tried all day to get the front calipers to catch but no luck. I'm getting lot's of fluid with no bubbles but no pressure on the piston. Thought maybe I had put the master cylinder together wrong so I took it a part and reassembled 3 times. Made no difference. Just can't get the pistons to work. Feed up with it now. Filled rereservoir and will let it sit over night. Maybe gravity will fix it. Any idea's.
Also, does the vacum hose attach to the carb first, then a short stub connects the boot to the octy? Also why the heck would they make gas line in yellow? what idiot came up with that? Why is the shy blue? I've had it, I'm going to bed!

[Bulldog9]

It takes a while for the lines and caliper to fill, I usually put a piece of tube on the bleeder and suck, or use a mini hand held vac. Once it starts flowing, gravity should to the rest. Once the lines and caliper are filed, you can start pumping and pressure will build. If you expect to pump them back up,well. you better have lots of time on your hands Not sure what you are talking about with the fuel lines.

[tinman905]

I have use the "mity Vac" with good results. Also some have held the calipers above the front master cylinder when bleeding the lines. "Speed Bleeder" make life easier also but not to be used with a "Mity Vac" pump.

The yellow fuel lines are ozone and UV light resistant and I believe other colors are available.

[petejw]

did you bleed the m/c first,
if its fitted on the bike, wrap a rag around the bango
bolt and crack it, depress the lever and see if there are any
bubbles coming out, if thats sweet, i place clear tubing on the bleeder
nipple on the caliper and into a small bucket with a bit of brake fluid in the bottom covering the hose, crack the bleeder and pump the lever til no air comes out, tighten the bleeder, do the same for the other side and you should be good to go,
also check the freeplay adj in your lever,
i noticed this helped a lot when its adj correctly,

[CatatonicBug]

Just can't get the pistons to work. Feed up with it now. Filled rereservoir and will let it sit over night. Maybe gravity will fix it. Any idea's.

As was mentioned, be sure you "bench-bleed" the master cylinder before attaching the brake line to it. Also, don't squeeze the handle all the way down when bleeding the brakes. Only take small, short strokes.

Also, does the vacum hose attach to the carb first, then a short stub connects the boot to the octy?

Here's a picture that shows how the lines connect:

Also why the heck would they make gas line in yellow? what idiot came up with that?

The yellow stuff is the GOOD stuff! Tygon line is yellow, and being see-through, you can see the fuel, and any air bubbles that might be causing an air lock in the lines. It's also much more plyable and durable than the black stuff.

Why is the shy blue?

I could answer that, but this post is already long enough...

[mack]

try again

Good morning. I have clear tubing attached to the bleeders and the other ends are in jars with brake fluid in them. Like I said, the MC is pushing the fluid to the calipers and I'm not getting any more bubbles at the bleeders. I primed the MC and the fact that it is pushing the fluid down to the bleeder makes me think it's ok. I'll try again today. Going to finish this coffee then head out to the dog house and prime the carbs and whatch for leaks at the T's and such, put the exhausts on then go for a start up. I'll work on the brakes again later. I got 25 feet of tygon, 3 feet of vacumn hose and some nuts and bolts for $40. Your right the tygon is nice to work with, but looks like sh..t.

[petejw]

have you checked the freeplay
between the lever and master cylinder,
i adj mine not to long ago and made a big difference.

[Suckerpunch]

Check again on how you put your MC together. I had this exact same problem last week. My problem was the cup that sits in front of the piston was placed in the wrong position. After the problem was found, I had great bleeding results.

Just a thought.

[mack]

no good news

Well the MC is toast. I managed to get good pressure on both front pistons but wont't last. My bother in law came over and he was pumping while I was bleeding. When putting the top back on I noticed bubbles blowing out of the bottom of the reservoir, between the plastic bowl and the aluminum. Didn't pick up on it soon enough so the paint is screwed. Doesn't matter though because I need a whole new unit. Hopefully they come in black not yellow. The Tygon is a bitch to work with in some respects. Short runs crimp real easy. Had to drop the carb T's well below the top of the boot so they didn't crimp when I set the tank down. Exhaust went on but the clamps were completely rusted through. Will see if I can find some on line. Obviously never got it started today but June 1 was my target date so I'm still on schedule.All I can say is I'm glad I didn't leave it in the sun with gas in it. I guess they don't make paint like they used to.

[Bulldog9]

Unless you want the stock look, you can buy a new MC from Mikes XS for $70 or so. Works much better than the rebuilt stock unit.

[Montreux_Blue]

As we all know, air rises, so while your pumping the air bubbles down, as soon as you let go of the lever where do the bubbles go, up.... I used one of these last time I rebuilt the master cylinder and both calipers. It was the quickest way to get rid of the hard to get bubbles since they are up high by the master cylinder anyways.... I just primed the lines with the master and bled the calipers first, then hooked it up and did the reverse bleed on the rest.

[fredintoon]

- - - Exhaust went on but the clamps were completely rusted through. Will see if I can find some on line. - - - All I can say is I'm glad I didn't leave it in the sun with gas in it. I guess they don't make paint like they used to.

Hi Mack,
for what is actually an upgrade on the stock exhaust pipe clamps, deke down to Princess Auto and buy the stainless steel T-bolt clamps you'll find in their hydraulics section.

Even 2-part auto paint has it's limits.
My tank paint had been happily ignoring gas spills for years but being soaked in it for some days did the paint in. Shows the difference between gas-resistant and gas-proof, eh?

[mack]

Clamps

The guy who owns the yama dealership near me used to have an xs 11. He is a supporter and gives me lot's of stuff and lets me root through all his old bins and shelves. I ordered a clamp today and asked if he had a speed bleeder. He asked if I would let him take it for a ride if he tuned it and bleed the brakes. I said ok but only for a short one. We both were grinning. I was riding it today with only partial fronts. Stupid I know but I couldn't help it. When it started after laying in the weeds for 18 years, I just had to hear it growl. God I'd forgotten how good this thing was. Must have been beginners luck because it's running smooth as silk all the way from 1100 up to 7000. Didn't want to go higher as the top end is all new. Figured I should at least let the oil get dirty first. I sat back and had a beer just looking at it when I got back and I can't beleve that it's the same bike I hooked a chain on last September and dragged out of the weeds. Brother in law and I had to winch it onto a trailer on it's side cuz the wheels wouldn't turn even after I pulled the calipers. Was going to sell it to a scrap metal yard but figured, what the heck, why not try. Really glad I did now.