[ElPaso]

I am trying to bleed my front breaks in the conventional manner using a clear hose attached to the bleed valve at one end and the other end flowing into a jar with a small amount of dot 4 fluid. When I pull on the brake lever the fluid flows well but doesn’t built up pressure. My question is, does the master cylinder reservoir cover have to closed and sealed tightly for the pressure to build up or can it be kept open. In some posts I have gotten the impression that I should be adding fluid as I operate the lever to make sure the master cylinder reservoir doesn’t become empty?

 

[alfacliff]

when the bleeder is open, the pressure is bled off, and does not build up. after you close the bleeder, it should work ok.
cliff

 

[ElPaso]

Alfacliff,

Thanks for the reply. I didn't word my question clearly enough. I am closing the bleed valve and the pressure is still not increasing. I understand that might be an indication that there is still air in the system. But my specific question is, does the master cylinder reservoir have to be closed in addition to the bleed valve for the pressure to be firm?

I appreciate any help.

 

[alfacliff]

no, he top dosnt have to be on to operate. in fact, if it is on, how do you see the level to keep the level from dropping tillit puts air back into the breaks?
cliff

 

[Matrix04]

I recently replaced the front brake line on my SM with a braided SS line from Spiegler. I found that the easiest way for me was to put clear tubing on both bleeder valves (each into a jar of fluid). Remove the master cylinder top and use the white plastic cap (the one between the gasket and the top) as a temporary cover. You'll want something to cover the M/C as when/if you pump the handle hard...it will splash fluid out of the cylinder. Make sure to keep plenty of fluid in the master cylinder when bleeding. I'm not sure that it makes a difference which caliper to start with, but I started with the one on the opposite side from the M/C. Open the bleeder valve and press the brake lever in then close the valve. Release the brake lever and then open the valve again. This time slowly pump the brake lever a few times then hold the lever in and tighten the bleeder valve. I went from one side to the other a couple of times and then finished by bleeding the caliper on the side with the M/C. Just take your time and all of the air will bleed out. Hope that helps.

 

[ElPaso]

Thanks Cliff & Matrix. You're responses are what was looking for. The weather has turned really cold so I am going to wait a couple of days before getting back to my speedy.

 

[ElPaso]

I bled the breaks today and it seems to have worked. Thanks for the replies. Ride safe