TheSamba.com :: View topic - dual master cylinder and not getting a firm pedal

Wed Apr 29, 2015 4:13 pm

I have bleed the brakes there are no air in the system. All the rubber hoses have been changed. The car stops put cannot lock the tires up. I adjusted all the brakes. So is there adjustments for the brake pedal? What else do I need to do?[/s]

Wed Apr 29, 2015 4:27 pm

asahi1234 wrote: I have bleed the brakes there are no air in the system. All the rubber hoses have been changed. The car stops put cannot lock the tires up. I adjusted all the brakes. So is there adjustments for the brake pedal? What else do I need to do?[/s]

Adjust the brakes again, all four drums. Bleed the brakes again. Check the pedal pushrod free play.

Wed Apr 29, 2015 4:47 pm

I have about 1inch of free play. And yes I have bleed the brake at least 6 times. And that's with two people.

Wed Apr 29, 2015 4:51 pm

shouldn't freeplay be 5-7mm (roughly 1/4")?

Wed Apr 29, 2015 7:23 pm

1" of free play is way to much. 808veedub is correct.

Wed Apr 29, 2015 8:14 pm

Did you bled the front circuit first?

Did you lock up the brake shoes before you bled the brakes??

As in turn the adjusting star till really tight to turn to the second adjusting star and crank that one till the drum is locked. Repeat on all four drums.

Wed Apr 29, 2015 8:24 pm

Bleed the rears first with all the shoes adjusted so the wheels are locked. Then bleed the fronts. Then let it sit for a couple hours and bleed it again, rear first, then front and then back the shoes off. I go 3 notches back in front 5 in rear. Then take it for a short drive and get the shoes centered in the drums. Then adjust them again. It's worked for me this way for years. Sometimes if they are very stubborn I will let them sit overnight after the first bleed and then try again.

And yes, 1" of free play is far too much.

brad

Thu Apr 30, 2015 7:30 am

I did the front first but did try adjusting the brakes be locked up. I will try this weekend.

Thu Apr 30, 2015 8:40 am

asahi1234 wrote: I did the front first but did try adjusting the brakes be locked up. I will try this weekend.

Think you meant to post "did not try adjusting the brakes to be locked up".

If so try that and do not pound the pedal when bleeding, try a slower pushing down on it. Too violent of pedal action can turn large easy to bleed bubbles into tiny bubbles that are really hard to bled.

If it still does not bleed after two or three tries, check that each adjusting star is still tight. So you will need to loosen the last star you cranked down on and turn drum to first adjusting star and see if it can be adjusted tighter, then back to the last star and relock down. Repeat for all four wheels.
Most brake shoes if not adjusted regularly properly or especially when new do not have same radius as the drum they are fitted into, so when you pump the brakes the shoes can squeeze farther down into the drum and loosen up against the wheel cylinder. Any looseness like this will allow the wheel cylinder to flex and reduce greatly your ability to push out the fluid with air bubbles out.

Above all, do not let the reservoir go dry when bleeding or you have to start all over again.

Mon May 04, 2015 7:39 am

Brake issue is fixed thanks to all that helped. What i did is adjust the brakes out so the wheels will not move. Bleed the front and then the back. Then backed of the brakes 2 clicks. And now the brake are firm. And again thanks alot.

Mon May 04, 2015 7:40 am

Good to hear. Thanks for the update. Enjoy!

Tue May 05, 2015 6:44 am

slalombuggy wrote: Bleed the rears first with all the shoes adjusted so the wheels are locked. Then bleed the fronts. Then let it sit for a couple hours and bleed it again, rear first, then front and then back the shoes off. I go 3 notches back in front 5 in rear. Then take it for a short drive and get the shoes centered in the drums. Then adjust them again. It's worked for me this way for years. Sometimes if they are very stubborn I will let them sit overnight after the first bleed and then try again.

And yes, 1" of free play is far too much.

brad
67 is first year for dual circuit brakes. dual circuit system means bleed front first. FR-FL-RR-LR