Everything is new, lines, res valve, wilwood alum. master, tuff stuff 7 in booster, I have bled and bled brakes, don't see any air. The brake pedal still goes all the way to the floor. I thought, without the motor on and creating vacuum, the pedal would be firm and only travel a couple inches. I'm curious if air is trapped before rear residual valve. I opened proportioning valve all the way up just to let any air out..
Any ideas? Please forgive the temporary proportioning valve bracket

 

You've created air traps in several places, particularly at the proportioning valve. Pressure bleeding is likely the only way to purge the system.

 

Residual valves are basically a one way valve that lets fluid flow freely one way, but holds a certain amount of backpressure the other. If you have them installed correctly with the proper direction of flow, that shouldn't be your problem. The number one cause of problems like yours is disc brake calipers installed incorrectly (typically left side on the right, and vice-versa) where the bleeder valve isn't all the way to the top and allowing a large pocket of air to remain unbleedable. You might check for that. The other question I would ask is did you bench bleed the m/c before installation? If you left air inside there, you'll experience the same symptoms. It can happen even though it looks full and is moving fluid. Good luck with your search. and keep us posted.

 

I did bench bleed the MC. All bleeder valves are at the top of caliper.

 

Do you get a stream of fluid when the bleeder is open and the pedal pressed?

 

I do get a steady stream. I just feel like the pedal should be stiffer. compared to modern day cars and trucks when the engine is off. I have never driven the 55 ford yet, so I have nothing to compare it to. I should try and post a video...

thx for your help

 

I agree 100% with what Ross said.

 

Looks to me like you have the Master below the brake lines and
even the wheel cylinders and calipers? The only way I have ever
got a system like that to bleed was a pressure bleeder. Than still
had problems with it down the road. No way can the fluid gravity
feed the system. It always seemed to draw in air from some where.
Mostly after sitting a few weeks. I would have to pressure bleed
almost every time I wanted to move it. I finally put a large reservoir
on the fire wall for fluid. That helped a lot as long as the system
stayed sealed. Be sure none of your fittings are sucking air. My .02c

 

When bleeding do you put a tight fitting plastic tube on the bleed screw and put the other end under the surface of a clear jar of brake fluid? That way you can watch the end of the tube and see any air come out and prevent air from being sucked back in while tightening the screw. Are you bleeding the wheels in the right order? What happens when the engine is running? Hold the pedal down and start the engine, the pedal should rise and get firm.

 

I will disclose one of my screw-ups in hopes that it saves someone else the 2 weeks it took me to find my problem. I had the same issue - spongy pedal and weak brakes. I built a pressure bleeder and still no luck.


Finally discovered that when I assembled the rear brakes, I never spun the adjusters out. Therefore, most of the fluid was going to the rears just trying to fill the cylinders enough to get the shoes to touch the drums.


Good luck and keep us posted.

 

but I have disc brakes on all four corners... does that matter?

Ax- I haven't started the motor yet. new rebuild. installing distributor and wiring next... just finished transmission lines..I have done the clear tube submerged in a clear bottle of brake fluid. no bubbles. even had my wife press pedal as I did the bleeder screw...

 

I jacked up the front wheels, spun them and hit the pedal. They stopped really quick. I think I might just be over analyzing. I should have it running in a couple weeks. I'll test out the brakes on a quick trip down the driveway. I'll report back

 

Edit:
Do you have these on your system?? I have used these to fix spongy pedals. Willwood brakes should be real firm.

 

Residual pressure valve...

 

My bad, I see one in your pics now.