Rear Brake No Pedal Pressure, Help, Please

[mabden]

Bleeding the rear brake with speed bleeder. Going well. Added a bit of DOT 4 twice. Fluid never got too low. For no apparent reason the brake pedal went to a "no pressure condition". Now, it won't pump fluid at all.

I will appreciate some advice, please.

Thanks very much in advance.
Mark

[mabden]

It's a 2000.
Mark

[Jinks]

Which bike? What year?

Have you tried bleeding with the stock bleed valve?

[mabden]

K1200 LT, 2000

Have not tried stock valve. I'm not sure how that would make a difference.

[mabden]

To clarify, no pressure with valve completely closed.
Thanks.
Mark

[zaphod]

You might have air in the line. Try a vacuum pump to bleed it.

[Jinks]

Only thing different than the stock configuration. Might have nothing to do with the problem, but it's worth eliminating the possibility.

[Zotter]

Added fluid to the wrong chamber?

Got an empty fluid reservoir you're not seeing?

[mabden]

Thanks.

As far as I know, the 2000 has only one reservoir for the rear brakes.

I used a vacuum pump at the wheel and at the pressure modulator to try to bleed the rear brake. All I am getting is air.

So, as I just had the brake pedal assembly "off" to do the transmission change, I'll check there next for a hose that may have become loose.

After that, I'll look at the master cylinder.

Still seeking advice.

Thanks.

[BecketMa]

<Fluid never got too low.>

Dumb things I have done:

Thought the cylinder behind the rear side case was for brake fluid. It never occurred to me the radiator over flow would be that far back in the bike.

Ordered two plugs and two valve cover gaskets for my 12K service.

I'll complete my list when I can stand more egg on my face.

Bob

[was]

Hey Mark. I just bled mine ('99), and was surprised at how long it took and how much air there was in the system. It would help to know:
1) Did you flush the system (remove all the old brake fluid)? If so, there is a lot of air to expell as you put in new fluid.
2) Did you use both bleeders at the rear caliper? If you have the Brembo brake there are two bleeders; if one of them is not tight, you may be getting an air leak there when using the other one.
3) Regarding the OEM bleeder screws - the manual says to use a 10 x 1 bleeder. I bought two at an auto parts store because my dealer did not have them in stock. The ones that I got are much longer than the BMW bleeders and don't seal well around the threads.
4) Are the bleeders at the ABS unit socked down tight? Air leak if not.
5) The hose from the reservoir to the master cylinder uses a crimp-on clamp at both ends, not a banjo fitting. Check that the hose is tight at both ends and is not kinked or squeezed due to repositioning the brake pedal cover.
6) If the hose to your bottle and vacuum pump is not getting a good seal around the bleeder screw you will be sucking in air.

HTH

[JPSpen]

The first time I bled the rear, I didn't remove the rubber bellows in the top of the brake res.
Just pulled the cap off and filled her up with fluid... Well the fluid was full but not in the res just in the top of the bellows that sets inside of the resevoir.

Also My master cylinder hose line failed and I lost brakes that way..

Even though the hose was bad and wouldn't develop any pressure, There was never any fluid visible....but it was a bad hose from dangleing it during service.

HTH.

JOhn

[schostev]

Are you guys opening the bleed valve and letting your reservoirs drain empty? If so I think you may be asking for trouble. I prefer to let them drain until the res. is almost empty, then filling with clean fluid. Then using clear tubing on each bleeder one at a time, start pumping the pedal or the handle never a complete stroke until you have perfectly clean fluid at the hoses. Of course you will have to fill the res. many times to cycle the old fluid out. Doing it in this manner will allow you to never get air in the system. Always use slow stokes and never completely to the stops.

Good Luck

[mabden]

Rubber Bellows not removed was my problem.

Egg on face.

Mark