Bench bleeding dual reservoir M/C 78 FJ40 (1 Viewer)

[agouge888]

New master cylinder came in for the 78 FJ40....I have started Bench bleeding it with two lines running from inlet ports looped around and down into each reservoir. I am using a vice to hold the M/C as I always do. I pumped the M/C about 20 times until it appears all of the air bubbles are gone, but I am still able to push the diaphragm in. I kept both reservoirs over 3/4 full the entire process. The end diaphram that I’m depressing with a blount screwdriver has some resistance, but I was under the impression it should get hard to where I can’t push it in at all? Let me know what I’m doing wrong or if this is correct? I feel if I can still push it in now...then when I mount it...my brakes will be spongy too.

Thanks,

Andy
agouge888

 

[reddingcruiser]

If the air is out of the M/C you are fine. Until the system is hooked up and the fluid can't go anywhere there won't be any significant resistance. Once you get everything installed and bleed you'll be fine.

 

[agouge888]

Never mind...I got it figured out...

Thanks
agouge

 

[agouge888]

Thanks for the reply ...it has 4 Wheel drums...and takes about 3 pumps of the pedal to get the pedal hard. I know I should start with farthest wheel to bleed, but how do I keep both cylinders in each wheel adjusted evenly?

Thanks

 

[handcannon]

When in the vehicle, and with the brakes fully assembled and bled you have the cylinders and shoes/drum providing something to stop the fluid flow, thus giving you the solid feel (when properly adjusted) to the brake pedal. At the current position you do not have anything to stop the flow of brake fluid, which will keep the solid stop feeling from being there. The brake fluid will continue to flow in a loop, from the piston in the MC, through the tubes which are turned back up and into the MC reservoir.

Once the MC is in the vehicle, and all the brake parts are assembled and properly adjusted, you will be able to feel the "wall" that will be there when you press the pedal.

Don

ps-my hunt and peck typing is too slow. glad you got it figured out.

 

[handcannon]

Thanks for the reply ...it has 4 Wheel drums...and takes about 3 pumps of the pedal to get the pedal hard. I know I should start with farthest wheel to bleed, but how do I keep both cylinders in each wheel adjusted evenly?

Thanks

No experience with this. I went directly to 4 wheel disc. I would assume that you start with both cylinders equally adjusted out until you can just fit the drum on. Then you will need to move one cylinder out a certain number of clicks, and then adjust out the other cylinder the same number of clicks. Do this until you get the drum to stop turning and then finish the adjusting procedure the way the FSM states.

Don