The Rodding Roundtable
Motorhead Message Central => Rodder's Roundtable => Topic started by: 57larry on June 23, 2022, 07:22:26 PM
I got another question guys.....have a 40 Ford sedan with a chevy 350/350 disc brakes, fron & rear. master cyl under the floor 1" bore has 2 residual valves, 6 inch power booster with a vacuum canister.
problem: brake pedal goes to the floor, car stops but I don't like the feel. disc brakes are wilwood, master cyl setup from ECI
thanks for any advice
soft pedal?
yes, soft pedal, bled many times
Do all the calipers have the bleeder screws right at the top? Do you have any of those through the frame brake line fittings ? Those 2 things can cause 'air pockets' in the system . Master was bench bled ? What is the pedal ratio?
yes, no yes
Fully bled and pedal goes to the floor . Is the volume of your master cyl able to supply the volume used in the calipers ?I would think with 1" bore it would . Does your pedal allow for a full stroke in the master cyl before it gets to the floor ?
Any chance the MC is bad. Not uncommon nowadays to be bad out of the box.
57Larry; As much as I relent from responding with advice, based upon my limited knowledge, I remember back 20 years ago when a member had a similar problem. He resolved his issue and a second members same problem by replacing the power booster canister with, in their cases a used Astro van unit, from the boneyard. They wanted one that was working hense the used boneyard part. Solved both issues quickly from soft to lock-up. I believe if the residual valves are holding then the booster canister is your issue. Hope I'm correct and your issue gets resolved. Let us know, Frank
Does the pedal go to the floor on a quick double-pump?
I'm done! taking out the master cyl & booster, going back to manual brakes. thanks for all the advice
Are the master cylinder and the booster a factory pair? Maybe the rod between the two is too long and not letting the brake cylinder retract all the way and letting the master cylinder re-fill with fluid. GPster
master cylinder, pedal, booster are from a kit from ECI
Go to the HAMB and look up a thread called " BRAKE BLEEDING!? " it was posted by ' Jaw 22 ' . On the 8th page of the thread he finds the problem . It caught me by surprize but would be worth a look on any system , especially those with under floor m/c .
thank you for the link, chimp
you are welcome . Those are the threads I like to read as a guy can usually learn something.
Helped a friend put a power disc brake kit on his 72 chevelle. Had the same problem as you. Had to adjust the small adjusting screw in between the master and the booster. Works great. It wasn't allowing the master to make a full stroke to grab brake fluid.