Front breaks are dead?

[teck_mountain]

Okay

I have changed the brake fluid, cleaned the lines and have every thing replaced on the front brakes of my 79 xs1100 special. Added brake fluid and pressed the lever. Nothing happened. followed the advice regarding bleeding brakes and still nothing happened. Dead, no pressure build up or anything.

However, up on closer expection I did notice drops of breake fluid coming from the back of the brake lever, where the screw depresses the plunger. I'm thinking this is a leak.

Does this mean I have to replace the master cylider? if so, is it a tough job?

thanks

Teck

[randy]

teck,

If you've already 'cleaned' the lines, how hard could it be to replace the master cylinder? it's just one line!

If, however, you mean to rebiuld the master cylinder and replace the plunger, spring and seals that is a horse of a different color.

There are quite a few threads here about rebuilding the M/C.

In the past, I've had success bleeding mine with the caliper raised above the handlebars, forcing the trapped air up the line. It's a wasted effort trying to force the air down the line.

Or, you can vacuum bleed them, but count on wasting a couple of bottles of fluid.

[teck_mountain]

Master cylinder

Sorry my mistake

I currently have the plunger out and cleaning everything. amount of crud inside the plunger cylinder was unreal! Also the one washer, or what ever it is called seemed to be out of place. (outside the grove. the boot covering the plunger is shot. However, everything else seems to be in good order?

teck

[randy]

While you've got it apart, just replace the plunger and seals. It's cheap insurance against brake failure.

ESPECIALLY THE FRONT!

[ratbyk]

Brake Bleeding

A trick I use when bleeding either the front or rear master on an XS is to have the cylinder off of it's mounting point. All lines are hooked up, everything is complete except for mounting the cylinder/s. Now proceed to bleed holding the cylinder at different angles. This moving around/rotating the cylinder seems to encourage any air trapped in the bore of the cylinder to rise up in the cylinder where you a have hope in h-ll of expelling it down the line to the caliper and then out of the system.
Ken/Sooke

[John]

Don't forget the angle of the M/C on the handle bars. You may have to loosen the handle bar clmps, and rotate them until the mcM/C is level or even pointed at a very slight downward angle. That way a bubble can't get trapped at a high spot where the line attaches to the M/C. Also, I have a Phoenix brand Reverse Brake bleeder that I use at work. It bleeds by attaching to the bleeder screw and forces fluid under pressure back into the M/C and chases the air out that way. Just make sure the reservoir is empty and the cover is on before you start. DAMHIKIJD

[prometheus578]

reverse bleed

I haven't used one of those Phoenix reverse bleeders. I just went to harbor Freight or somewhere and bought a small red "pump" oilcan. Filled it with brake fluid, attached a hose to it and the caliper bleed screw, and pumped the fluid in and up to the M/C reservoir. Don't let the res get full and overflow.

When flushing a good brake system and cleaning out the gunk in the reservoir, I used a hypodermic syringe type thingie. Can be bought from any farm and feed store for a few bucks. Lets you suck out all the old fluid, clean the res with Q tips, and then fill up with fresh fluid before bleeding/flushing. As long as you don't squeeze the lever when it's dry and you're cleaning, no air gets into the system.

[John]

Another neat trick to flushing out a brake system is to use isopropyl (rubbing) alcohol to thoroughly clean the system of gunk and moisture. It dries quickly and doesn't leave any residue. I use my Mighty Vac for emptying the reservior. I have tried to bleed the system with the Mighty Vac, but wasn't pleased with the results. I still had to finish by hand. I'll bet that 'frugal' oil can works as well as that $150 Phoenix Injector does. It does generate a lot of pressure though. I've used it on a bunch of older F 700-800's with good results.

[teck_mountain]

Brake problem solved (I hope)

Thanks for the advice

Truly XSive; I tried your idea with using the oil can and it worked like a charm. Brakes seem to be functional.

I don't have the boot on the end of the plunger as it was worn and tore upon removal. I will order a kit. However, is this a must have thing?

[TopCatGr58]

Hey Teck,

"Truly Xsive" is just a little rank every one earns here as they post, once you go over 100 posts, just look at your own name, you've got it, too! I think you meant to address Prometheus.

That cover is mostly a dust and water shield, along with dressing up the lever area, but it's not critical for operation! Glad you got the brakes to work!
T.C.

[teck_mountain]

breaks

Hey Top Cat

Thanks for the info. I'm up and runnin. I hope the weather holds as I need to ride!!!!