Hey guys 5 hours later and I need help please?

[Suckerpunch]

No joke I spent 5 hours trying to prime my front master brake cylinder. I just did it a few days ago and after a few pumps of the hand brake, I was able to bleed the calipers. Now I pump and Pump and pump and so on, NOTHING.

The oil level stays the same. If I place my finger on the bleeder I can feel a push pull pulsation. What should I do?

Please chime in...

[draketrumpet]

I had a similar push pull sensation on my rear brakes. On the rod in the MC, there was a metal plate with 3 or 4 small holes that were clogged. Go through every little hole in the MC with brake cleaner and a needle or thin wire, make sure everything is so sparkling clean you can see yourself.

If I remember right, those small holes allow fluid to get into the chamber and then be pushed down through the lines, kind of like a one way valve.

[Suckerpunch]

I had a similar push pull sensation on my rear brakes. On the rod in the MC, there was a metal plate with 3 or 4 small holes that were clogged. Go through every little hole in the MC with brake cleaner and a needle or thin wire, make sure everything is so sparkling clean you can see yourself.

If I remember right, those small holes allow fluid to get into the chamber and then be pushed down through the lines, kind of like a one way valve.

I did that. I used almost a full can of brake cleaner. There is two little holes. I was able to run the cleaner hose down both of them and blow them out. I know it was a success because I allowed the brake fluid run out the area you would hook the brake line to. Tons of nasty oil was blown out. I did it until it was crystal clear. I even lubed it with fresh oil then blew it out again. I repeated this process about 4 times.

I just cant figure out if im doing something wrong.

But thanks,

[perurider]

can you loosen where the hose hooks and squeeze and hold the lever and then tighten it back up and let go of lever? and still nothing? mine was doin that and i got pi//ed and started pushing the piston w/a screwdriver and seen the brake lever just wasnt pushing piston all the way in on master cyl.

[WMarshy]

What year is your bike? I believe its harder to get them bled if you have the linked break lines. (The back master cylinder is linked to the front so when you use the back break it activates the front left.)

[Suckerpunch]

can you loosen where the hose hooks and squeeze and hold the lever and then tighten it back up and let go of lever? and still nothing? mine was doin that and i got pi//ed and started pushing the piston w/a screwdriver and seen the brake lever just wasnt pushing piston all the way in on master cyl.

Hahaha

Did all that too...

Niothing

[MindWebs]

by "oil" i hope you mean brake fluid...

DOT 3 brake fluid cannot be mixed with oil.

hmm, brake systems need a little help when i tcomes to bleeding them..

don't just pump the MC with the bleeder open.

meaning.... place your finger over the end of the bleeder and lightly press on it. as you slowly pump the MC, let the air blow out of the bleeder but let your finger seal the bleeder from air going back it.

it takes a light touch.. and it sounds silly. but the MC can pull air up the lines much easier then it can draw fluid from the resivior.

so you have to slowly force it to draw fluid.

Good Luck

[Suckerpunch]

What year is your bike? I believe its harder to get them bled if you have the linked break lines. (The back master cylinder is linked to the front so when you use the back break it activates the front left.)

1980 xs1100 lg

Sorry guys I should have posted that in the first place.

Im almost sure they are separate.

[Suckerpunch]

by "oil" i hope you mean brake fluid...

DOT 3 brake fluid cannot be mixed with oil.

hmm, brake systems need a little help when i tcomes to bleeding them..

don't just pump the MC with the bleeder open.

meaning.... place your finger over the end of the bleeder and lightly press on it. as you slowly pump the MC, let the air blow out of the bleeder but let your finger seal the bleeder from air going back it.

it takes a light touch.. and it sounds silly. but the MC can pull air up the lines much easier then it can draw fluid from the resivior.

so you have to slowly force it to draw fluid.

Good Luck

yes, "oil" brake fluid.

sorry to say I did that too.

Thanks all. Im sure well get there.Has to be several different ways to do it.

[draketrumpet]

You're sure you got the little tiny holes on the rod itself, not in the master cylinder.


looking at this image, the 4 holes I'm talking about are just below the number 2 and a little to the left. A little hard to see here, but the pic is also in the manual. 4 little holes right there in the middle.

Also, try a bench bleed. if you get the same push-pull at the MC, you know your problem is there. If you can bleed the MC just fine, then you may need to replace your lines or find some obstruction in the lines to clean out.

[Suckerpunch]

You're sure you got the little tiny holes on the rod itself, not in the master cylinder.


looking at this image, the 4 holes I'm talking about are just below the number 2 and a little to the left. A little hard to see here, but the pic is also in the manual. 4 little holes right there in the middle.

Also, try a bench bleed. if you get the same push-pull at the MC, you know your problem is there. If you can bleed the MC just fine, then you may need to replace your lines or find some obstruction in the lines to clean out.

Ahhhhh...

Nope I didnt go that far.

[Incubus]

Did you pull the pistons and clean out the calipers when you did the master? There are only a few things to make these brakes work. Is the master pumping when you squeeze the lever? If unsure, pull the brake line from the master and squeeze the lever with your finger over the hole the fluid comes out of. It should squirt a little past your finger. Are the brake lines clear and full of fluid? Is there an air leak? Are the calipers freezing?

My money is on an air leak at one of the junctions of brake line and component. If they worked a few days ago but not now, I'd be looking for a slow leak. Did you reuse the copper crush washers? I've done that, but it didn't always work out.

Patrick

[Suckerpunch]

Did you pull the pistons and clean out the calipers when you did the master? There are only a few things to make these brakes work. Is the master pumping when you squeeze the lever? If unsure, pull the brake line from the master and squeeze the lever with your finger over the hole the fluid comes out of. It should squirt a little past your finger. Are the brake lines clear and full of fluid? Is there an air leak? Are the calipers freezing?

My money is on an air leak at one of the junctions of brake line and component. If they worked a few days ago but not now, I'd be looking for a slow leak. Did you reuse the copper crush washers? I've done that, but it didn't always work out.

Patrick

Long story short. I had my left caliper freezing up and my right caliper was doing all the work. I removed the calipers and cleaned them up (remover pistons and seals and did a real good cleaning). It was then I started having problems building pressure to bleed. I kept removing brake lines like until it was just my finger over the end of the master cylinder. If I put some "oil" in the brake line hole I build strong out pressure but, once I remove my finger I get nothing.

[Suckerpunch]

If I were to pull the calipers and the master cylinder, would anyone here care to do a complete cleaning and rebuild on them for me (paid of course)?

I really like to learn and do the work my self but, brakes are probably something I should leave to a pro for safety reasons.

Just a thought?

Daniel

[CatatonicBug]

Don't let the brakes intimidate you. They are super simple, and don't take much to get them working right. I recently found a cheap tool at Harbor freight that helps a lot. A one-man bleeder that only costs $5.

Start by filling the Master Cylinder with fluid. This is BEFORE you put the piston in it. Once the piston is installed, fill the reservoir and cover the hole that the banjo bolt screws into with your finger (tightly). When you squeeze the lever, DO NOT squeeze all the way! Only half pumps each time. This is true for the ENTIRE bleeding process. Squeeze the lever, release the pressure under your finger, then put your finger back, and let the lever go. Squeeze again, and repeat this several times until the fluid squirts out past your finger.

Also, be sure to pour fluid into the caliper and rock it back and forth to get as much of the air out as possible, BEFORE connecting the brake line to it. Remember that you do not need to have the caliper connected to the wheel to bleed it. A small block of wood between the pads will keep them apart enough to put it on the bike when you're done bleeding.