Front Brake Help

[tdecotis]

I have a 2005 250 that I just replaced the front and rear brakes with stainless steel lines. The rear brake works great and the front brake was working before I installed the new line but now nothing. I have tried properly bleeding the front brake but the issue I am having is that the brake fluid is not even leaving the master cylinder and going thru the line. The reservoir has stayed full after 10 minutes of trying to bleed the old fashion (wrench on bleeder valve and squeezing brake). Any suggestions will help. Thanks.

[cuong-nutz]

Piston in the MC might be stuck due to corrosion. No amount of pumping the lever works?

[chugs]

A mity vac would make the brake bleeding process easier, harbor freight has a similar one for cheap.

[crazymadbastard]

crack open the line at the MC and use it like a bleeder-loose and tighten to let air out the MC, if not then mighty vac time.

[tdecotis]

I took both pistons out and cleaned them. When I put the pistons back in I lubed them with brake fluid so I don' think that is the issue. As I mentioned the front brakes were working just before I installed the new lines. The bike just needed new pads and the lines had never been changed so I did everything for the front and rear. I know a minivac would help but do you think it would solve the problem.

[crazymadbastard]

Originally Posted by crazymadbastard

crack open the line at the MC and use it like a bleeder-loose and tighten to let air out the MC, if not then mighty vac time.

[tdecotis]

I attempted to bleed from the master cylinder. Some fluid dripped from the banjo but it was still not a significant amount. I cleaned the master cylinder and put new brake fluid in but still the same result when trying to bleed from the top. I will try to get my hands on a mighty vac today and try again.

Someone mentioned that maybe the pistons are stuck or corroded in the master cylinder but it was working just fine earlier today when the old lines were on which is why I don't want to believe that is the answer although it might be.

[GeorgeRYoung]

This worked for me.

Make sure the two little ports at the bottom of the master cylinder are clear, a toothpick helps. Position the handlebars so that the master cylinder is at the highest point.

With the bleeder bolt at the caliper closed, squeeze the lever a bit, you should see some bubbles rise out of the new line. Release and repeat.

[csmith12]

You can't "really" pump bleed brakes on a bike like you would on a car. There is just not enough movement of air/fluid to get the job done.

I force feed my fluid in through the bleeder valve on the caliper via a piece of clear tubing (same tubing I use to wrap my safety wire) and believe it or not..... a jagermeister shot pump. Yep, in true KY genius fashion.



Kill 3 birds with one stone;

clear tubing for safety wire - check
clear tubing to force feed brake fluid by fitting tightly over the valves - check
liquor for the mechanic trying to bleed brakes without a vac - check

lol

[crazymadbastard]

so you really need to reverse bleed the darn thing.

[Lychee]

Originally Posted by tdecotis

I attempted to bleed from the master cylinder. Some fluid dripped from the banjo but it was still not a significant amount. I cleaned the master cylinder and put new brake fluid in but still the same result when trying to bleed from the top. I will try to get my hands on a mighty vac today and try again.

Someone mentioned that maybe the pistons are stuck or corroded in the master cylinder but it was working just fine earlier today when the old lines were on which is why I don't want to believe that is the answer although it might be.

If something is blocking the flow of fluid, you will need to reverse bleed and remove the blockage. Or you can take apart the master cylinder and clean the internals and not just the bowl. Sucking harder from the bleeder nipple with the mighty vac will just force the blockage deeper into the master cylinder or worse, the lines.

[tdecotis]

Originally Posted by Lychee

If something is blocking the flow of fluid, you will need to reverse bleed and remove the blockage. Or you can take apart the master cylinder and clean the internals and not just the bowl. Sucking harder from the bleeder nipple with the mighty vac will just force the blockage deeper into the master cylinder or worse, the lines.

I attempted to back bleed and some fluid got in but it seems like something is clogged near the master cylinder. I took the MC off the bike and removed the brake lever. I am having a tough time removing the rubber piece and spring in the master cylinder. I don't want to force it out with pliers which is all I can think to do right now. I can't find anything on the site that shows a master cylinder rebuild. Anyone know a way to get this piece out?

[tdecotis]

http://www.newmotorcycleparts.com/to...rebuild_2.html

I found a link that helped. Guess I do just go at it with pliers.

[Asspire]

probably dislodged some crud built up in the master when you pulled the lever all the way in, pull apart and rebuild master, don't want a cup seal to fail while riding.

[Lychee]

Originally Posted by tdecotis

I attempted to back bleed and some fluid got in but it seems like something is clogged near the master cylinder. I took the MC off the bike and removed the brake lever. I am having a tough time removing the rubber piece and spring in the master cylinder. I don't want to force it out with pliers which is all I can think to do right now. I can't find anything on the site that shows a master cylinder rebuild. Anyone know a way to get this piece out?

Did you take out the snap ring? Part# 43022 in the picture.

[tdecotis]

Thanks for all the help. I took the master cylinder apart and cleaned it. I was then able to reverse bleed the bike and now have my front brakes back.

[cuong-nutz]

Good stuff

[csmith12]