Brake fluid level the problem.....?

[STRider]

Ok, well I took it for a spin and all feels good. If it were clogged I am guessing it would be hard to stop or it would
be noticeably worse? Also the clutch would feel mushy/different?

I'd love members with more experience with fail modes in these systems to chime in, but... You mention that the clutch and brakes work correctly. If the obstruction I suggested was in the port of the bleed screw, then no, it shouldn't prevent it from operating 'normally'. With air removed and the system full of fluid between the master cylinder at the bar, and the slave cylinder in the clutch, or the pistons of the brakes, they should work. But my hypothetical obstruction would only prevent the exit of fluid via the bleeder when it was opened to do so.

What was the condition of the fluids that you displaced from the clutch slave cylinder or the brake calipers? You called it 'dirty'. Was it just discolored? Was is cloudy or emulsified? (think milky in appearance) Was there any floating debris in it?

 

[interceptor44]

Discolored and a lot of black residue on the inside of the clear flush tube. Emptied fluid from tube and black
residue remained stuck on inside of tube.

 

[Bush]

You should have been able to pump fluid through that system until the cows came home. Something is amiss, either in your technique, or within the system itself, but I have no guesses on that to offer.

 

[rwthomas1]

That little hand powered master cylinder can develop a couple thousand pounds pressure. Unlikely anything is stuck. When you bleed brakes, its a bit different than the clutch. With the clutch, you are compressing the springs, so releasing the pressure at the slave cylinder bleeder simply allows the springs to push the fluid out. When bleeding brakes, you will feel the pressure when you squeeze the brake lever. Squeeze brake lever and hold that pressure, like when you are braking. Then crack the bleeder screw on the caliper you are working on. The pressure in the brake lever should release, and allow you to squeeze the brake lever right to the grip. When this happens, HOLD THE LEVER TIGHT TO THE GRIP! Keep that lever held tight, and tighten the bleeder screw. Then release. Repeat. Following that sequence exactly you shouldn't have any problems. If by chance the pressure does NOT release when you loosed the bleeder screw, then the bleeder screw port is obstructed. Remove the bleeder screw and clear it with a paperclip, etc. Note, if you remove the bleeder screw, brake fluid will drip rather rapidly as the master cylinder reservoir drains by gravity. If you need to fiddle with the bleeder screw for any length of time, plug that hole. I find used ear plugs work decent for this.

RT

 

[Roger]

It all sounds so complex! Connect the clear pipe and drop the other end in a container. Pull the lever/press the pedal and crack the bleed nipple just enough for fluid to flow. ...And it is only just enough... Release the lever/pedal and carry on pumping. If you have set it right, there will be a lot of resistance. Air does not get back in. Top up the reservoir as needed. When the fluid comes out nice and clean, tighten the nipple, adjust the levels and it's done. If air gets sucked in at the reservoir 'cos you weren't watching, just tap/agitate the lever and the bubbles will come up. Never had any problem.

 

[interceptor44]

That little hand powered master cylinder can develop a couple thousand pounds pressure. Unlikely anything is stuck. When you bleed brakes, its a bit different than the clutch. With the clutch, you are compressing the springs, so releasing the pressure at the slave cylinder bleeder simply allows the springs to push the fluid out. When bleeding brakes, you will feel the pressure when you squeeze the brake lever. Squeeze brake lever and hold that pressure, like when you are braking. Then crack the bleeder screw on the caliper you are working on. The pressure in the brake lever should release, and allow you to squeeze the brake lever right to the grip. When this happens, HOLD THE LEVER TIGHT TO THE GRIP! Keep that lever held tight, and tighten the bleeder screw. Then release. Repeat. Following that sequence exactly you shouldn't have any problems. If by chance the pressure does NOT release when you loosed the bleeder screw, then the bleeder screw port is obstructed. Remove the bleeder screw and clear it with a paperclip, etc. Note, if you remove the bleeder screw, brake fluid will drip rather rapidly as the master cylinder reservoir drains by gravity. If you need to fiddle with the bleeder screw for any length of time, plug that hole. I find used ear plugs work decent for this.

RT

Ok, going to leave for now as the brakes are working well. It did do that when I opened the bleeder the handle went all the way
to the grip. Did it on both front bleeders. Dispensed old fluid and some dirty black stuff maybe two times....on both.
The rear did what it was supposed to do, I emptied the reservoir about 3 times! Thanks...will try cleaning bleeder screws when
I get a chance.

 

[rwthomas1]

Ok, going to leave for now as the brakes are working well. It did do that when I opened the bleeder the handle went all the way
to the grip. Did it on both front bleeders. Dispensed old fluid and some dirty black stuff maybe two times....on both.
The rear did what it was supposed to do, I emptied the reservoir about 3 times! Thanks...will try cleaning bleeder screws when
I get a chance.

It would be preferrable that you bleed the front, or really ANY system until clean fluid comes out.

RT

 

[interceptor44]

It would be preferrable that you bleed the front, or really ANY system until clean fluid comes out.

RT

Yes, going to attempt again this weekend ...will not be riding bike that much until then...thanks.

 

[ST1100Y]

That little hand powered master cylinder can develop a couple thousand pounds pressure. Unlikely anything is stuck.

Well, on the CX500 Eurosport I'd refurbed some time ago, one banjo-fitting was corroded shut -> zero fluid movement of the front MC...
So anything seems possible...