Brakes: Stiff Brake Pedal/No Fluid to Rear Cylinders? (Solved)

[studebaker-R2-4-me]

I've installed a new master cylinder and brake booster and the correct linkages and rods from Myers. New brake lines and hoses. Even added Turner Disc Brake package.

With the vacuum connected to the booster. I can feel the assist when the peddle depressed (really stiff) then start the engine, the peddle pulls in more.

I've manually bench bled the master. Added brake fluid. Successfully beld the Turner Disk front, leaving the rears. Can't seem to get fuild to the rears.

I unthreaded the rear circuit from the master and have a proportioning valve in the Master cylinder.

Do I remove this valve to bled the rears?

Allen

[StudeRich]

Dual or Single Master Cyl.? I think your Car would be a Disc. brake Car originally, so with the stock M/C without the residual Valve, it does NOT need a Proportioning Valve, if the stock Rear 11 inch finned Truck Brakes are sill in use.

It is Way Overcomplicated with a Proportioning Valve, and certainly also if it has a Dual M/C.
Sorry, with a modified Car I can't help.

[studebaker-R2-4-me]

My bad, residual valve. Duel Master 1 1/16" stroke. Lark origanally had drums all round, small master cylinder, 259 V8. Now R1 289 killer cam and heads, power shift and Dana 44.

[JoeHall]

Are you working on a Hawk or a Lark?

[studebaker-R2-4-me]

1963 Lark Convertible.

[Warren Webb]

I take it that the original drums are being used in the rear, correct? Leave the proportioning valve in place. Crack open the right rear wheel cylinder & with low air pressure, disconnect & blow out the line to the rear brakes. This insures there are no obstructions in the line. Reconnect & bleed starting at the r/r wheel cylinder. Bleeding the brakes on a "dual" system is no different than on a single. The routine is the same.

[studebaker-R2-4-me]

Yes the original drums are being used from the Dana 27 converted to the Dana 44 axle. I've redone all the metal brake lines on the car. All is new, ....everything front and rear!

[DieselJim]

Just saw a NOS master cylinder that the second plunger saw stuck.

[studebaker-R2-4-me]

Thought I should post a picture of my master cylinder setup.

The rear circuit is off the front of the master cylinder. When I cracked the nut on the rear brake line circuit and had my fiance Caroline pressing on the brake pedal there was little to no brake fluid coming out this outlet. I can see the residual valve in the outlet. Is this blocking the fluid? I need this residual valve in the rear circuit? I'm tempted to remove it and bleed the brakes, then re install if necessary.

I have a hard time believing a blockage in new brake lines. But I will remove the rear wheel cylinder vent plugs and blow this circuit out with low pressure air. I am also thinking of removing the master one more time to bench bled it again to see if brake fuild will pump out the master cylinder.

To clarify. New Turner Brake Disc setup on the fronts, new brake lines front and back, new hoses (3), new rear wheel cylinders, new brake shoes in rear. really stiff hard brake peddle. I can tell the brake booster is working since the peddle moves down when I have pressure on the peddle and then start the car.

Allen

[StudeRich]

OK I get it now, you are working on the Lark Daytona, I should have known that.

It sounds like you are saying that you have the original 10 Inch Drum Brake Rear drum setup and no proportioning Valve, but with a Dual M/C conversion with a Residual Valve ONLY in the Front Port for the Rear Brakes. That sounds correct.

So for proper operation AFTER you get the rears working, you may want to reverse the Wedges at the top brake shoe anchor to prevent rear wheel lockup, since you are using Self Energizing Drum Brakes with Disc. fronts and a high pressure Dual Master-Vac Booster.

[Pat Dilling]

I recently went through a similar experience and finally found that one of my brand new brake hoses was plugged. Defective from the manufacturer. It's something for you to check if you haven't already.

[studebaker-R2-4-me]

I recently went through a similar experience and finally found that one of my brand new brake hoses was plugged. Defective from the manufacturer. It's something for you to check if you haven't already.

I haven't made it out to the shop today to blow out the rear circuit yet but I've been thinking since yesterday something is going on with the Master Cylinder. When I have good foot pressure on the brake pedal and crack open the rear circuit from the master. I am getting no movement in the pedal. This tells me the master's rear circuit is blocked, the second piston is not moving or the rod length totally off. I don't get bubbles in the reservoir when applying pressure to the pedal. All this means no fluid to the rears.

Am I thinking right?


Allen

[studebaker-R2-4-me]

I'm out in my shop now. Re-bench bled the master. Noticed how far the piston would move for optimal braking. The offending part was the adjustable pushrod in the booster. It was retracted all the way in but was still to long. I cut a grade 8 bolt fine thread head off, drilled the tip of the now stud so that I could use an extractor to get it out or adjust it as needed. The cause of my issue was that the master was at was at near full plunge before pressing brake pedal.

Allen

[JoeHall]

I'm out in my shop now. Re-bench bled the master. Noticed how far the piston would move for optimal braking. The offending part was the adjustable pushrod in the booster. It was retracted all the way in but was still to long. I cut a grade 8 bolt fine thread head off, drilled the tip of the now stud so that I could use an extractor to get it out or adjust it as needed. The cause of my issue was that the master was at was at near full plunge before pressing brake pedal.

Allen

How could that be? In the OP you said you'd installed, "the correct linkages and rods from Myers." Soo Myers sent you incorrect parts?

[Studebaker1962]

For the over thinker in all of us:

Ockham's razor (also written as Occam's razor and in Latin lex parsimoniae) is a principle of parsimony, economy, or succinctness used in problem-solving devised by William of Ockham